Loading...
HomeMy WebLinkAboutBritton_SWPPP_ReportREV5A Storm Water Pollution Prevention Plan for Proposed Britton Single Family Home Subdivision Town of Lansing Lansing, New York September 2019 REV December 2020 Prepared by: Timothy C. Buhl, PE NYSPE#: 053134 For: Scotty & Wayne Britton 18 Murfield Drive Ithaca, NY 14850 TABLE OF CONTENTS 1.0 EXECUTIVE SUMMARY .................................................................................. 1 2.0 INTRODUCTION...............................................................................................5 3.0 PROJECT DESCRIPTION...............................................................................8 4.0 RUNOFF REDUCTION VOLUME ..................................................................9 5.0 STORM WATER POLLUTION PREVENTION MEASURES AND CONTROLS.......................................................................................................11 6.0 LOCAL PLANS.................................................................................................14 7.0 STATE HISTORIC PRESERVATION.......................................................... 14 8.0 ENVIRONMENTAL MAPPING..................................................................... 15 9.0 INSPECTIONS AND SYSTEM MAINTENANCE .......................................15 10.0 POST CONSTRUCTION INSPECTION, OPERATION AND MAINTENANCE................. ...........................................................................17 ATTACHMENTS Attachment A: Notice of Intent, (NOI) and MS4 Acceptance Form (if applicable) Attachment B: Notice of Termination, (NOT) Attachment C: Certification Forms Attachment D: State Historic Preservation Mapping Attachment E: Environmental Mapping Attachment F: Inspection Report (Sample Form) Attachment G: Record of Stabilization and Construction Activity Dates Attachment H: Vegetative and Structural Measures for Erosion and Sediment Control New York State Standards & Specifications for Erosion and Sediment Control Attachment I: NYSDEC Stormwater Controls Construction Checklist Attachment J: NYSDEC Controls Operation & Maintenance Check List Attachment K: Stormwater Management Summary 1.0 EXECUTIVE SUMMARY The engineer, owner and all contractors involved with construction activity that disturb site soil or who implement pollutant control measures identified in the Storm Water Pollution Prevention Plan (SWPPP) are responsible for complying with the requirements set forth in the New York State Department of Environmental Conservations SPDES General Permit from Construction Activity Permit No. GP-0-20-001 and any local and/or state governing agencies having jurisdiction with regards to erosion and sediment control. The requirements of the SPDES Permit are as follows: A. Owner: Scotty & Wayne Britton 18 Murfield Drive Ithaca, NY 14850 (607) 275-9677 Project Site: Tax Parcel#37.1-4-2.12 N. Triphammer Road Lansing, NY 14882 This project is subject to the requirements of a regulated, traditional land use control MS4. Therefore, the following requirements must be met before a construction activity is authorized to discharge stormwater. 1. An owner or operator that is subject to the requirements of a regulated, traditional land use control MS4, must have its SWPPP reviewed and accepted by the regulated MS4 prior to submitting the NOI to the Department. The owner or operator shall then have the "MS4 SWPPP Acceptance Form," as provided in Attachment A, authorized by the MS4 and submitted to the Department along with the NOI for approval. 2. Complete the Notice of Intent (NOI) provided in Attachment A and forward to the recipients following this section. Five (5) business days from the date the Department receives a complete electronic version of the NOI (eNOI) for construction activities with a SWPPP that has been preopared in conformance with the design criteria in the technical standard referenced in Part III.B.1. of the SPDES General Permit and the performance cirteria in the technical standard referenced in Parts III.B., 2 or 3 of the SPDES general permit, for construction activities that require post-construction stormwater management practices pursuant to Part III.C. of the SPDES General Permit; or Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, AT 3. Sixty (60) business days from the date the Department receives a complete NOI (electronic or paper version) for construction activities with a SWPPP that has not been prepared in conformance with the design criteria in technical standard referenced in Part III.B.1. or, for construction activities that require post-construction stormwater management practices pursuant to Part III.C., the performance criteria in the technical standard referenced in Parts III.B., 2 or 3, or; 4. Ten (10) business days from the date the Department receives a complete paper version of the NOI for construction activities with a SWPPP that has not been prepared in conformance with the design criteria in technical standard referenced in Part III.B.l. or, for construction activities that require post-construction stormwater. NYS Department of Environmental Conservation (DEC) Division of Water 625 Broadway, 4th Floor Albany, New York 12233-3505 Town of Lansing Town Hall 29 Auburn Road Lansing, New York 14882 (607) 533-4142 All notifications shall be sent via certified mail with return receipt. Copies of mailing receipts shall be kept on record at the project site with the SWPPP and shall be considered part of the contract documents. The Town's representative shall be included in the pre-construction meeting. Copies of the SWPPP must be provided to the Town of Lansing once all signatures and attachments are complete. B. A copy of the General Construction Permit (GP-0-20-001), Notice of Intent (NOI), NOI acknowledgement letter received by the DEC, and MS4 Acceptance Form (if applicable), shall be posted in a prominent place for public viewing at the project site. C. A complete copy of the SWPPP, NOI, NOI Acknowledgement letter, MS4 Acceptance form (if applicable), including copies of all inspection reports, plan revisions, etc., must be retained at the project site at all times during working hours and kept as part of the permanent project records for a duration of no less than five (5) years following submission of the Notice of Termination (NOT). 2 1 P a g e Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,NY D. The site development contractors must provide names and addresses of all subcontractors working on the project who will be involved with the major construction activities that will result in soil disturbance. The Owner shall ensure that each contracting firm identifies one trained individual who will be responsible for implementation of the SWPPP. The owner shall also ensure that at least one trained individual is on site daily when soil disturbance activities are being performed. This information must be retained as part of the SWPPP. E. The site development contractor and all subcontractors involved with the major construction activities that disturb site soil must sign a copy of the appropriate certification statement included in Attachment C along with the identity of the appropriate trained individual as described in paragraph D of this section. F. Regular inspections must be made to determine effectiveness of the SWPPP. It would be modified as needed to prevent pollutants from discharging from the site. The inspector must be a person familiar with the site, the nature of the major construction activities, and qualified to evaluate both overall system performance and individual component performance. Additionally, the inspector must either be someone empowered to implement modifications to the SWPPP and the pollutant control devices, if needed, in order to increase effectiveness to an acceptable level, or someone with the authority to cause such events to happen. G. This SWPPP must be updated each time there is a significant modification to the pollutant prevention system or a change of contractors working on the project who may disturb site soil. The site development contractor must notify the governing agency(s) as soon as these modifications are implemented. H. Discharge of oil or other hazardous substances into the storm water is subject to reporting and cleanup requirements. Refer to Part I.B.l.d of the SPDES General Permit for additional information. Copies of the SPDES General Permit and the Notice of Intent Forms may be found on-line. I. Notice of Termination (NOT) - Once the site reaches final stabilization upon completion of the project, Scott & Wayne Britton, as Owner, may terminate coverage of SPDES permit coverage by submitting a Notice of Termination, Form (included in Attachment B), when one or more of the following conditions are met: 1. Total Project Completion - All construction activity identified in the SWPPP has been completed; and all disturbance have achieved final 3 1 P a g e Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, NY stabilization and all temporary, structural erosion and sediment control measures have been removed, and all post-construction stormwater management practices have been constructed in conformance with the SWPPP and are operational. 2. Planned shutdown with partial project completion — All soil disturbance activities have ceased; and all areas disturbed as of the project shut down date have achieved final stabilization, and all temporary, structural erosion and sediment control measures have been removed, and all post- construction stormwater management practices have been constructed in conformance with the SWPPP and are operational. 3. A new owner or operator has obtained coverage under the General SPDES Permit in accordance with Part II.E. 4. The owner or operator obtains coverage under an alternative SPDES General Permit or individual SPDES permit. For construction activities meeting 1.0.I above, the owner or operator shall have a qualified inspector perform a final site inspection prior to submitting the NOT. The qualified inspector shall, by signing the "final stabilization" and "Post-Construction Stormwater Management Practice certification statements on the NOT, certify that all requirements of the SPDES General Permit have been met. Further, construction activities subject to the requirements of a regulated, transitional land use control MS4, must have the MS4 sign the "MS4 acceptance" statement on the NOT, indicating that the project has been constructed in accordance SPDES General Permit requirements. Lastly, for construction activities that require post-construction stormwater management practices, the owner or operator must, prior to submitting the NOT, ensure one of the following: 1. The post-construction stormwater management practices and any right of ways needed to maintain such practices have been deeded to the municipality in which the practice is located. 2. An executed maintenance agreement is in place with the municipality that will maintain the post-construction stormwater management practices. 3. If the post-constructed management practices are privately owned, the owner or operator must have a mechanism in place that requires operation and maintenance of the practices in accordance with the 4 1 P a g e Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, AT operation and maintenance plan, such as a deed covenant in the owner or operator's deed of record. 4. If the post-constructed practices are owned by a public or private institution, government agency or authority, or public utility, the owner or operator has policy and procedure in place that ensures operation and maintenance of the practices in accordance with the operation and maintenance plan. J. This SWPPP intends to control water-borne and liquid pollutant discharges by some combination of interception, filtration, and containment. The general contractor and subcontractors implementing this SWPPP must remain alert to the need to periodically refine and update the SWPPP in order to accomplish the intended goals. K. This SWPPP must be amended as necessary during the course of construction in order to keep it current with the pollutant control measures utilized at the site. Amending the SWPPP does not mean that it has to be reprinted. It is acceptable to add addenda, sketches, new sections, and/or revised drawings. L. A record of the dates when major grading activities occur, when construction activities temporarily or permanently cease on a portion of the site, and when stabilization measures are initiated must be maintained until the NOT is filed. A log for keeping such records is included in Attachment G. A different form for the log may be substituted if it is found to be more useful. 2.0 INTRODUCTION This SWPPP has been prepared for major activities associated with the construction of a 10 single family home subdivision consisting of 1,100-SF homes, a maintenance building, associated driveways, landscaping, public water and sewer. The Britton Subdivision is located in the Town of Lansing, New York at Tax Parcel#37.1-4-2.12, approximately 1,500 feet north of the intersection of Asbury Road and N. Triphammer Road and 700 feet south of Sharon Drive. The property sits within a drainage area of approximately 36.63-AC of which, the cumulative land disturbance will be approximately 8.75 acres. The additional total impervious cover added to the site will be 11% based on the calculated ratio of proposed new impervious surface area to existing pervious. Reference the Project Plans for the permanent stormwater management facilities planned. This SWPPP includes the elements necessary to comply with the SPDES General Permit for Stormwater Discharges GP-0-20-001 administered by the New York State Department of Environmental Protection, the U.S. Environmental Protection Agency (EPA) under the National Pollutant Discharge Elimination System (NPDES) program and all local governing 5 1 P a g e Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,NY agency requirements. This SWPPP must be implemented at the start of construction. Construction phase pollutant sources anticipated at the site are disturbed (bare) soil, vehicle fuels and lubricants, chemicals associated with building construction, and building materials. Without adequate control there is the potential for each type of pollutant to be transported by storm water. Aside from the commercial construction, the project includes, asphalt driveways, an access road, landscaping, public water and private sewer, as well as connections to other service utilities ie. (gas, electric, phone). Permanent stormwater management facilities are proposed including one (1) dry pond, a perimeter diversion swale, two (2) grassed swales, and eight (8) green infrastructure filter strips to address runoff reduction volume concerns. The pond will provide any remaining water quality volume treatment beyond the green infrastructure and satisfy requirements for quantity attenuation as necessary to control runoff to less than pre-developed conditions as required by the NYSDEC General SPDES Permit. Please see Attachment K for this information. A. Purpose The major goal of pollution prevention efforts during project construction is to control the migration of soil and pollutants that originate on-site and prevent them from impacting surface waters and the environment. The purpose of this SWPPP is to provide guidelines for achieving that goal. A successful pollution prevention program also relies upon careful inspection and adjustments during the construction process in order to enhance its effectiveness. B. Scope This SWPPP must be implemented before construction begins on the site. It primarily addresses the impact of storm rainfall and runoff in areas of the ground surface disturbed during the construction process. In addition, there are recommendations for controlling other sources of pollution that could accompany the major construction activities. This SWPPP will terminate when disturbed areas are stabilized, construction activities covered herein have ceased, and a completed Notice of Termination (NOT) is mailed to the governing agency requiring the NOT. See Section 1.0.I for specific NOT eligibility requirements. Particular forms are included which are necessary for implementing the SWPPP. 6 Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, NY The SPDES General Permit for Storm Water Discharges from Construction Activities prohibits most non-storm water discharges during the construction phase. Allowable non-storm water discharges that could occur during construction on this project, which would therefore be covered by the General Permit, include: 1. Discharges from fire fighting activities; 2. Fire hydrant flushing; 3. Waters to which cleansers or other components have not been added that are used to wash vehicles or control dust; 4. Routine external building washdown which does not use detergents; 5. Irrigation drainage; 6. Uncontaminated discharges from construction site de-watering operations; 7. External building wash down which does not use detergents; 8. Runoff from pavement wash down where spills or leaks of toxic or hazardous materials have not occurred (unless all spilled material has been removed) and where detergents have not been used; 9. Air conditioning condensate; 10. Springs and uncontaminated groundwater; and 11. Foundation or footing drains where flows are not contaminated with process materials such as solvents. The techniques described in this SWPPP focus on providing control of pollutant discharges with practical approaches that utilize readily available expertise, materials, and equipment. The Owner/Developer referred to in this SWPPP is Scott & Wayne Britton who will be responsible for full development and build-out of the subject parcel. 7 1 P a g e Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, AT 3.0 PROJECT DESCRIPTION Described below are the major construction activities that are subject to this SWPPP. The Owner shall not disturb greater than five (5) acres of soil at any one time without prior written authorization from the DEC, or, in areas under the jurisdiction of a regulated MS4, authorization by that municipality. They are presented in the order (or sequence) they are expected to begin, but each activity will not necessarily be completed before the next begins. Install erosion and sediment control measures as shown on Drainage, Sediment and Erosion Control Plans, down slope from construction activities that disturb site soil before disturbance of soil; CONSTRUCTION PHASE 1 A. Construction of stabilized construction entrance(s); B. Placement of silt fence; C. Construction of dry pond and associated access road swales necessary to bring runoff into practice(s) from areas as shown on design plans ST-11. D. Construction of development roadway to gain access to each individual construction area. E. Construction activities for the development of buildings and associated driveway/parking area: a. Construct driveways and individual lot temporary parking; b. Construct general utility services (ie. water and sewer piping, storm piping, etc.) c. Construct buildings; d. Construct other utility service connections (gas, electric, phone); e. Construct filter strips as shown on site plans. Note: For all Underground Utilities — Sediment barriers such as silt fencing, proper seeding and mulching will be utilized as required to bind the down slope side of utility construction and soil stockpiles; F. Remove any accumulated sedimentation from the pond forebays, and associated swales. Return property to permanent lines and grades; 8I Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, NY G. Final Grading Mulching & Seeding — Sediment barriers will be maintained down slope from disturbed soil during these operations; H. Completion of site stabilization, ie. Vegetative cover, driveway surface. Sediment & Erosion Controls to remain in place until vegetative cover reaches 80% density. 4.0 RUNOFF REDUCTION VOLUME This project follows guidelines set forth by the DEC for runoff reduction. Chapter 3 of the New York State Stormwater Management Design Manual requires a five step planning process to document compliance with required processes. Step 1 — Protect natural resources and utilize site hydrology This planning step is designed to preserve area natural resources by protecting areas, avoiding sensitive locations, and minimizing grading and soil disturbances. There were no erodible soils, critical areas, wetlands, riparian buffer areas, or locally listed protected areas. Another component of the planning process is an evaluation of all green infrastructure practices that might be acceptable for runoff reduction on site. This project will utilize filter strips. The selection process is described as follows: o Conservation of natural areas — Pre-development hydrology and water quality characteristics of undisturbed natural areas remains unaltered. o Sheetflow to riparian buffers — None were available on-site. o Vegetated open swales — Site runoff will be collected and directed to specific treatment practices by way of diversion swales and direct sheet flow. o Tree planting/tree box — This was not a specific reduction practice considered for this project. o Disconnection of rooftop runoff — Roof downspouts and driveways will be sheet flowed across grassed filter strip surfaces. o Stream daylighting for redevelopment projects —None on site. o Bioswale— Grassed filter strips will be used for water quality treatment. 9 1 P a g e Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, AT o Green roof — This practice was cost prohibitive to the project and is impractical for individual homes. As such, this option was not considered. o Stormwater planters — Grassed filter strip areas will control runoff from rooftop and driveway areas due to the large surface areas involved. o Rain cistern — This practice was considered impractical for the overall usage and square footage of the developed parcels. Source control measures using a bioretention area and rain garden was considered instead. o Porous pavement - This practice was cost prohibitive to the project and as such, this was not considered. Step 2 — Determine Overall Water Quality Treatment Volume (WQv) See Attachment K for the calculation summary. Step 3 — Runoff reduction by pplyinggreen infrastructure technology and standard SMPs. Green infrastructure techniques were evaluated to potentially reduce the overall water quality volume. Green infrastructure practices used for this project were identified in Steps 1 and 2. The majority of site controls was through the use of eight grassed filter strip areas allowing for an impervious cover credit in overall water quality volume and runoff reduction volume calculations. As shown in Attachment K, minimum requirements for runoff reduction volume were met. Step 4 — Provide standard practices to address remaining water quality volume A dry pond and associated forebays will treat for the remaining water quality volume so that 100% is met across the site. Reference Attachment K for the overall treatment calculations. Step 5 —Apply volume and peak rate control practices if still required Peak rate control is met using one dry pond. The pond reduces runoff from the proposed development to less than pre-developed conditions. See modeling report output for further information. 101Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, AT 5.0 STORM WATER POLLUTION PREVENTION MEASURES AND CONTROLS Various erosion and sediment control measures have been incorporated into the design of the project, Reference Stormwater, Sediment and Erosion Control Plans accompanying this SWPPP. These measures will be implemented during construction to minimize soil erosion and to protect the character and integrity of downstream receiving waters. Eight grassed filter strips, two grassed swales, and a dry pond will remain upon completion of the project to control the quality and quantity of storm water runoff from the developed site. The site development contractor shall take all appropriate precautions to prevent soil erosion and discharge of sediment and other pollutants to receiving water bodies and wetlands. Specific measures are outlined in this plan. In general, disturbance areas shall be limited to the smallest practical areas at any given time, and the areas are to be reseeded as soon as possible. During construction the measures outlined in this document and shown on the plans are to be installed as described. Additional measures may be warranted or required by site and climatic conditions. Specific erosion control measures, designed to minimize soil loss, and sediment control measures devised to retain eroded soil and prevent it from reaching water bodies or adjoining properties have been developed in accordance with the New York State Stormwater Management Design Manual, 2015, NYSDEC and New York Standards & Specifications for Erosion and Sedimentation Control, November 2016. Reference Attachment H for copy of Vegetative and Structural, Measures for Erosion and Sediment Control, New York State Standards & Specifications for Erosion and Sedimentation Control. (Vegetative; November 2016, Structural; August 2005) A variety of storm water pollutant controls are recommended for this project. Some controls are intended to function temporarily and will be used as needed for pollutant control during the construction period. These include temporary sediment and erosion control measures as shown on the plans and permanent stormwater facilities including, grassed filter strips, grassed swales, a dry pond, and a diversion swale. For all disturbed areas, permanent stabilization will be accomplished by covering the disturbed soil with vegetation, pavement, or commercial structures. A. Erosion and Sediment Controls 1. Soil Stabilization — The purpose of soil stabilization is to prevent soil from leaving the site. In the natural condition, soil is stabilized by native vegetation. The primary technique to be used under this project 11IPage Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,NY for stabilizing site soil will be to provide a protective cover of turf grass, pavement, or building structure. a. Temporary Seeding - Where land disturbance is necessary, temporary seeding with fast-germinating temporary seed and a protection of mulch must be used on areas which will be exposed for more than 14 days. b. Permanent Seeding — All areas at final grade must be seeded and mulched within 7 days after completion of the major activity. c. Structural Controls — The storm water will be managed on site utilizing proposed site grading, grassed filter strips, pond, and associated drainage systems. Their design is shown on the Project Site Stormwater Plans. Final site stabilization is achieved when there is a uniform 80 percent density of permanent vegetation on all previously disturbed soil surfaces, exclusive of areas that have been paved. B. Other Pollutant Controls Control of sediments has been described previously. Other aspects of this SWPPP are listed below: 1. Dust Control — Construction traffic must enter and exit the site at the stabilized construction/driveway entrance. The purpose is to trap dust and mud that would otherwise be carried off-site by construction traffic. Dust control must be provided by the general contractor to a degree that is acceptable to the Owner, and in compliance with applicable local and state dust control regulations. After construction, the site will be stabilized (as described elsewhere), which will reduce the potential for dust generation. 2. Solid Waste Disposal — No solid materials, including building materials, are allowed to be discharged from the site with storm water. All solid waste, including disposable materials incidental to the major construction activities, must be collected and placed in containers. The containers will be emptied periodically by a contract trash disposal service and hauled away from the site. 121Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, NY Substances that have the potential for polluting surface and/or groundwater must be controlled by whatever means necessary in order to ensure that they do not discharge from the site. As an example, special care must be exercised during equipment fueling and servicing operations. If a spill occurs, it must be contained and disposed so that it will not flow from the site or enter groundwater, even if this requires removal, treatment, and disposal of soil. In this regard, potentially polluting substances should be handled in a manner consistent with the impact they represent. 3. Sanitary Facilities —All personnel involved with construction activities must comply with state and local sanitary or septic system regulations. Temporary sanitary facilities will be provided at the site throughout the construction phase. They must be utilized by all construction personnel and will be serviced by a commercial contractor. 4. Water Source — Non-storm water components of site discharge must be clean water. Water used for construction, which discharges from the site, must originate from a public water supply or private well approved by the State Health Department. Water used for construction that does not originate from an approved public supply must not discharge from the site. It can be retained in temporary ponds until it infiltrates and evaporates. 5. Long-Term Pollutant Controls — Storm water pollutant control measures installed during construction that will also provide benefits after construction, include one (1) dry pond, two (2) grassed swales, and eight (8) grassed filter strips. Those sediment barriers, such as check dams, that do not interfere with normal operations and appear to provide long-term benefits can be left in place after construction is completed. All silt fencing must be removed once the site has received proper stabilization. C. Construction Phase "Best Management Practices" During the construction phase, the general contractor will implement the following measures: 1. Permanent traffic corridors shall be established and "routes of convenience" shall be avoided; 2. Preservation of existing vegetation as much as possible. Following the completion of construction activities in any portion of the site permanent vegetation shall be established an all exposed soils; 131Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,NY 3. Site preparation activities shall be planned to minimize the area and duration of soil disruption; 4. Minimizing soil erosion and sedimentation by stabilization of disturbed areas and by removing sediment from construction site discharges; 5. Material resulting from the clearing and grubbing operation will be stockpiled up slope from adequate sedimentation controls. 6. The general contractor will designate areas for equipment cleaning, maintenance, and repair. The general contractor and subcontractors will utilize those areas. The areas will be protected by a temporary perimeter berm. 7. Use of detergents for large scale washing is prohibited (i.e., vehicles, buildings, pavement surfaces, etc.) 8. Chemicals, paints, solvents, fertilizers, and other toxic material must be stored in waterproof containers. Except during application, the contents must be kept in trucks or within storage facilities. Runoff containing such material must be collected, removed from the site, treated and disposed at an approved solid waste or chemical disposal facility. 6.0 LOCAL PLANS In addition to this SWPPP, construction activities associated with this project must comply with any guidelines set forth by local and state regulatory agencies. Reference Project Plans and the Stormwater Management Design Summary (Attachment K) prepared to meet Local and State requirements for post- development stormwater quantity & quality. 7.0 NYSHPO A search was conducted on the New York State Parks, Recreation and Historic Preservation Office website to identify whether the subject parcel is listed under natural or historic places registration, or if the area resides within an archaeologically sensitive location. Although Attachment D, includes a "grey map" indicating that the property is not within a sensitive area, the project is currently awaiting a no-impact statement from SHPO. 141Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,11Y 8.0 ENVIRONMENTAL MAPPING A search was conducted on the Tompkins County, New York State, and Federal Inventory websites to identify any areas with known wetlands, protected plants or animal species, or any significant environmental concerns that could be impacted by this project. No issues or concerns were noted. Please see Attachment E for screen prints of this review. 9.0 INSPECTIONS AND SYSTEM MAINTENANCE Between the time this SWPPP is implemented and final site stabilization is achieved, all disturbed areas and pollutant controls must be inspected at least once every seven calendar days by a licensed professional or Qualified Inspector, as identified by the SPDES General Permit. The purpose of site inspections is to assess performance of pollutant controls. The inspections will be conducted by an independent third party Qualified Inspector to be provided by the Owner using a form similar to the example provided in Attachment F. The Owner/Operator will also be required to arrange for a designated Trained Contractor (as defined by the SPDES General Permit) to be responsible for the management of this SWPPP during construction, while on-site. Based on these inspections, the Trained Contractor will decide whether it is necessary to modify this SWPPP, add or relocate sediment barriers, or whatever else may be needed in order to prevent pollutants from leaving the site via storm water runoff. The Trained Contractor has the duty to cause pollutant control measures to be repaired, modified, maintained, supplemented, or whatever else is necessary in order to achieve effective pollutant control. Examples of particular items to evaluate during site inspections are listed below. This list is not intended to be comprehensive. During each inspection the inspector must evaluate overall pollutant control system performance as well as particular details of individual system components. Additional factors should be considered as appropriate to the circumstances. A. Construction of stormwater facilities. Insure facilities are constructed substantially in accordance with the plans. (Also, Reference Attachment I for sample inspection checklist - NYSDEC Stormwater Construction Checklist): B. Locations where vehicles enter and exit the site must be inspected for evidence of off-site sediment tracking. A stabilized construction entrance will be constructed where vehicles enter and exit. This entrance will be maintained or supplemented as necessary to prevent sediment from leaving the site on vehicles. 151Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,NY C. Sediment barriers must be inspected and, if necessary, they must be enlarged or cleaned in order to provide additional capacity. All material from behind sediment barriers will be stockpiled on the up slope side. Additional sediment barriers must be constructed as needed. D. Inspections will evaluate disturbed areas and areas used for storing materials that are exposed to rainfall for evidence of, or the potential for, pollutants entering the drainage system. If necessary, the materials must be covered or original covers must be repaired or supplemented. Also, protective berms must be constructed, if needed, in order to contain runoff from material storage areas. E. Grassed areas will be inspected to confirm that a healthy stand of grass is maintained. The site has achieved final stabilization once all areas are covered with building foundation or pavement, or have a stand of grass with at least 80 percent density. The density of 80 percent or greater must be maintained to be considered as stabilized. Areas must be watered, fertilized, and reseeded as needed to achieve this goal. F. All discharge points must be inspected to determine whether erosion control measures are effective in preventing significant impacts to receiving waters. Based on inspection results, any modification necessary to increase effectiveness of this SWPPP to an acceptable level must be made within seven calendar days of the inspection. The inspection reports must be completed entirely and additional remarks should be included if needed to fully describe a situation. An important aspect of the inspection report is the description of additional measures that need to be taken to enhance plan effectiveness. The inspection report must identify whether the site was in compliance with the SWPPP at the time of inspection and specifically identify all incidents of non-compliance. Inspection reports must be kept on file by the Trained Contractor as an integral part of this SWPPP for at least five years from the date of completion and filing of NOT for the project. Ultimately, it is the responsibility of the site Trained Contractor to assure the adequacy of site pollutant discharge controls. Actual physical site conditions or contractor practices could make it necessary to install more structural controls than are shown on the plans. (For example, localized concentrations of runoff could make it necessary to install additional sediment barriers.) Assessing the need for additional controls and implementing them or adjusting existing controls will be a continuing aspect of this SWPPP until the site achieves final stabilization. 161Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing,11Y 10.0 POST CONSTRUCTION INSPECTION, OPERATION AND MAINTENANCE PLAN A. Maintenance Responsibility Short and Long term maintenance responsibilities for the grassed filter strips, dry ponds, diversion swales, and associated drainage infrastructure will be within a drainage district carried by deed through individual lot owner. Specifically, each lot owner will be aware that the following shall be incorporated into the project as part of an O&M post construction management plan: 1. A sign shall be erected in a conspicuous area (ie. close proximity to each developed practice) to identify each stormwater management practice including: the grassed filter strips, dry pond, and associated swales, and perimeter diversion swale,. The sign shall be of a size not less than 18" x 24" (or 10" x 12" for footprints smaller than 400 SF) bearing the following information: STORMWATER MANAGEMENT PRACTICE Project Identification (SPDES Permit #) [Grassed filter strips, dry pond, swale(s)], (insert structure description as appropriate) Must be maintained in Accordance with O&M Plan 2. Maintenance responsibility for individual filter strip areas, dry pond and associated swales and drainage systems, shall lie with each lot owner. 3. Copies of the practice designs and details shall be kept on record and be made available at all times. Copies shall also be forwarded to the Town of Lansing for archival purposes. B. Sediment & Debris Removal For grassed filter strip areas, sediment shall be cleaned out at the base of the porous berms when it accumulates to a depth of more than three inches. Trash and debris shall be removed as necessary. Silt/sediment shall be removed from forebays of the dry pond when the accumulation exceeds 6 inches. The removed sediments shall be disposed in an acceptable manner (ie. Landfill) 171Page Stormwater Pollution Prevention Plan Britton Single Family Home Subdivision (T)Lansing, NY A stone drop (pea gravel diaphragm) of at least six inches shall be provided at the edge of all driveways leading to a grassed filter strip area. C. Inspection & Periodic Maintenance To ensure the continued operation and long term performance of the proposed stormwater management system(s), inspections shall be conducted periodically for the first few months following construction and then on an annual basis. Site inspection should also be performed following major storm events (i.e., intense storms, thunder storms, cloud bursts, etc.). Items to check for include, but are not limited to the following: (Reference Attachment J for complete inspection checklist - NYSDEC Stormwater Operation, Maintenance and Management Inspection Checklists): i) Embankment & Structural; ❑ Check basin embankments, outlets and spillways note cracks, bulges, animal burrows, differential settlement, damage to or fatigue of stormwater pipe, structures and permanent erosion control. Components of the system that require repair or replacement should be addressed immediately following identification. Check pipes, channels, grates, inlet structures and spillways to insure design capacity. Look for objects or accumulations of sediments and debris obstructing flow path. ii) Vegetation; ❑ Preclude deep rooted woody plant growth on structure embankment by mowing at least once annually. ❑ Maintain a dense vigorous growth of grass cover. Spot seed, mulch and fertilize where necessary. 18111agc Attachment A: Notice of Intent, (NOI) and MS4 Acceptance Form (if applicable) 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 N01 - Britton Subdv Alternate ID Britton Single Family Home Subdivision Submission HPO-2901-2K6PN Revision 1 Form Version 1.28 Review This step allows you to review the form to confirm the form is populated completely and accurately, prior to certification and submission. Please note: Any work you perform filling out a form will not be accessible by NYSDEC staff or the public until you actually submit the form in the 'Certify & Submit' step. OWNER/OPERATOR INFORMATION Owner/Operator Name(Company/Private Owner/Municipality/Agency/Institution,etc.) Scotty &Wayne Britton Owner/Operator Contact Person Last Name(NOT CONSULTANT) Britton Owner/Operator Contact Person First Name Scotty &Wayne Owner/Operator Mailing Address 18 Murfield Drive City Ithaca https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 1/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 State NY Zip 14850 Phone 6072759677 Email slbritton@att.net Federal Tax ID None Specified PROJECT LOCATION Project/Site Name Britton Single Family Home Subdivision Street Address(Not P.O. Box) N.Triphammer Road Side of Street East City/Town/Village(THAT ISSUES BUILDING PERMIT) Lansing State NY Zip 14882 https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 2/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 County TOMPKINS DEC Region 7 Name of Nearest Cross Street Sharon Drive Distance to Nearest Cross Street(Feet) 700 Project In Relation to Cross Street South Tax Map Numbers Section-Block-Parcel 37.1-4-2.12 Tax Map Numbers None Specified 1.Coordinates Provide the Geographic Coordinates for the project site.The two methods are: - Navigate to the project location on the map (below) and click to place a marker and obtain the XY coordinates. -The "Find Me" button will provide the [at/long for the person filling out this form.Then pan the map to the correct location and click the map to place a marker and obtain the XY coordinates. Navigate to your location and click on the map to get the X,Y coordinates Latitude Longitude 42.533392025774425 -76.49055431166992 PROJECT DETAILS https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 3/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 2.What is the nature of this project? New Construction 3.Select the predominant land use for both pre and post development conditions. Pre-Development Existing Landuse Forest Post-Development Future Land Use Single Family Subdivision (Please answer 3a) 3a. If Single Family Subdivision was selected in question 3,enter the number of subdivision lots. 10 4. In accordance with the larger common plan of development or sale, enter the total project site acreage, the acreage to be disturbed and the future impervious area (acreage)within the disturbed area. *** ROUND TO THE NEAREST TENTH OF AN ACRE. *** Total Site Area(acres) 9.70 Total Area to be Disturbed(acres) 8.75 Existing Impervious Area to be Disturbed(acres) 0 Future Impervious Area Within Disturbed Area(acres) 1.00 5. Do you plan to disturb more than 5 acres of soil at any one time? No https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 4/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 6. Indicate the percentage (%) of each Hydrologic Soil Group(HSG) at the site. A(%) 0 B(%) 41 CM 59 D(%) 0 7. Is this a phased project? No 8. Enter the planned start and end dates of the disturbance activities. Start Date 9/15/2020 End Date 9/15/2022 9. Identify the nearest surface waterbody(ies)to which construction site runoff will discharge. Unnamed creek which receives N. Triphammer Road R.O.W. ditch runoff 9a.Type of waterbody identified in question 9? Other Type Off Site (enter description below) Other Waterbody Type Off Site Description Road R.O.W. swale to unnamed creek to Gulf Creek to Cayuga Lake https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 5/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 9b. If"wetland"was selected in 9A, how was the wetland identified? None Specified 10. Has the surface waterbody(ies in question 9 been identified as a 303(d)segment in Appendix E of GP-0-20-001? No 11. Is this project located in one of the Watersheds identified in Appendix C of GP-0-20-001? No 12. Is the project located in one of the watershed areas associated with AA and AA-S classified waters? Yes If No,skip question 13. 13. Does this construction activity disturb land with no existing impervious cover and where the Soil Slope Phase is identified as an E or F on the USDA Soil Survey? No If Yes,what is the acreage to be disturbed? None Specified 14.Will the project disturb soils within a State regulated wetland or the protected 100 foot adjacent area? No 15. Does the site runoff enter a separate storm sewer system (including roadside drains, swales, ditches,culverts,etc)? Yes 16.What is the name of the municipality/entity that owns the separate storm sewer system? (T) Lansing 17. Does any runoff from the site enter a sewer classified as a Combined Sewer? No 18.Will future use of this site be an agricultural property as defined by the NYS Agriculture and Markets Law? No https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 6/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 19. Is this property owned by a state authority,state agency,federal government or local government? No 20. Is this a remediation project being done under a Department approved work plan?(i.e.CERCLA, RCRA,Voluntary Cleanup Agreement,etc.) No REQUIRED SWPPP COMPONENTS 21. Has the required Erosion and Sediment Control component of the SWPPP been developed in conformance with the current NYS Standards and Specifications for Erosion and Sediment Control(aka Blue Book)? Yes 22. Does this construction activity require the development of a SWPPP that includes the post-construction stormwater management practice component(i.e. Runoff Reduction,Water Quality and Quantity Control practices/techniques)? Yes If you answered No in question 22,skip question 23 and the Post-construction Criteria and Post-construction SMP Identification sections. 23. Has the post-construction stormwater management practice component of the SWPPP been developed in conformance with the current NYS Stormwater Management Design Manual? Yes 24.The Stormwater Pollution Prevention Plan (SWPPP)was prepared by: Professional Engineer (P.E.) SWPPP Preparer Timothy C. Buhl, PE Contact Name(Last, Space, First) Gibson, Scott Mailing Address 5 Orchard Avenue City Watkins Glen https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 7/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 State New York Zip 14891 Phone 6072280662 Email scottgibsonl 98@gmail.com Download SWPPP Preparer Certification Form Please take the following steps to prepare and upload your preparer certification form: 1) Click on the link below to download a blank certification form 2)The certified SWPPP preparer should sign this form 3) Scan the signed form 4) Upload the scanned document Download SWPPP Preparer Certification Form Please upload the SWPPP Preparer Certification No files uploaded Comment At least one file is required. None Specified EROSION & SEDIMENT CONTROL CRITERIA 25. Has a construction sequence schedule for the planned management practices been prepared? Yes 26.Select all of the erosion and sediment control practices that will be employed on the project site: https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 8/19 NEW YORK Qepartment of STATE Or OPPORTUNITY Environmental Conservation SWPPP Preparer Certification Form SPDES General Permit for Stormwater Discharges From Construction Activity (GP-0-20-001) Project Site Information Project/Site Name Britton Wood Subdivsion Owner/Operator Information Owner/Operator (Company Name/Private Owner/Municipality Name) Scotty&Wayne Britton Certification Statement — SWPPP Preparer I hereby certify that the Stormwater Pollution Prevention Plan (SWPPP) for this project has been prepared in accordance with the terms and conditions of the GP-0-20-001. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of this permit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings. Timothy IC [Buhl First name MI Last Name Signature Date Revised:January 2020 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 Temporary Structural Check Dams Silt Fence Stabilized Construction Entrance Biotechnical None Vegetative Measures Seeding Topsoiling Permanent Structural Land Grading Diversion Other None Specified POST-CONSTRUCTION CRITERIA * IMPORTANT: Completion of Questions 27-39 is not required if response to Question 22 is No. 27. Identify all site planning practices that were used to prepare the final site plan/layout for the project. Roadway Reduction Building Footprint Reduction 27a. Indicate which of the following soil restoration criteria was used to address the requirements in Section 5.1.6("Soil Restoration")of the Design Manual(2010 version). All disturbed areas will be restored in accordance with the Soil Restoration requirements in Table 5.3 of the Design Manual (see page 5-22). 28. Provide the total Water Quality Volume(WQv)required for this project(based on final site plan/layout).(Acre-feet) 0.108 https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 9/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 29. Post-construction SMP Identification Use the Post-construction SMP Identification section to identify the RR techniques (Area Reduction), RR techniques(Volume Reduction) and Standard SMPs with RRv Capacity that were used to reduce the Total WQv Required (#28). Identify the SMPs to be used by providing the total impervious area that contributes runoff to each technique/practice selected. For the Area Reduction Techniques, provide the total contributing area (includes pervious area) and, if applicable, the total impervious area that contributes runoff to the technique/practice. Note: Redevelopment projects shall use the Post-Construction SMP Identification section to identify the SMPs used to treat and/or reduce the WQv required. If runoff reduction techniques will not be used to reduce the required WQv, skip to question 33a after identifying the SMPs. 30. Indicate the Total RRv provided by the RR techniques(Area/Volume Reduction)and Standard SMPs with RRv capacity identified in question 29.(acre-feet) 0.04 31. Is the Total RRv provided(#30)greater than or equal to the total WQv required (#28)? No If Yes,go to question 36. If No,go to question 32. 32. Provide the Minimum RRv required based on HSG. [Minimum RRv Required =(P)(0.95)(Ai)/ 12,Ai=(s)(Aic)](acre-feet) 0.024 32a. Is the Total RRv provided (#30)greater than or equal to the Minimum RRv Required(#32)? Yes If Yes,go to question 33. Note: Use the space provided in question #39 to summarize the specific site limitations and justification for not reducing 100% of WQv required (#28). A detailed evaluation of the specific site limitations and justification for not reducing 100% of the WQv required (#28) must also be included in the SWPPP. If No, sizing criteria has not been met; therefore, N01 can not be processed. SWPPP preparer must modify design to meet sizing criteria. https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 10/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 33.SMPs Use the Post-construction SMP Identification section to identify the Standard SMPs and, if applicable,the Alternative SMPs to be used to treat the remaining total WQv (=Total WQv Required in #28 -Total RRv Provided in #30). Also, provide the total impervious area that contributes runoff to each practice selected. NOTE: Use the Post-construction SMP Identification section to identify the SMPs used on Redevelopment projects. 33a. Indicate the Total WQv provided (i.e.WQv treated)by the SMPs identified in question#33 and Standard SMPs with RRv Capacity identified in question#29. (acre- feet) 0.064 Note: For the standard SMPs with RRv capacity, the WQv provided by each practice =the WQv calculated using the contributing drainage area to the practice - provided by the practice. (See Table 3.5 in Design Manual) 34. Provide the sum of the Total RRv provided(#30)and the WQv provided (#33a). 0.104 35. Is the sum of the RRv provided(#30)and the WQv provided (#33a)greater than or equal to the total WQv required(#28)? Yes If Yes, go to question 36. If No, sizing criteria has not been met; therefore, NOI can not be processed. SWPPP preparer must modify design to meet sizing criteria. 36. Provide the total Channel Protection Storage Volume(CPv required and provided or select waiver(#36a), if applicable. CPv Required (acre-feet) 0.203 https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 11/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 CPv Provided (acre-feet) 0.23 36a.The need to provide channel protection has been waived because: None Specified 37. Provide the Overbank Flood(Qp)and Extreme Flood(Of)control criteria or select waiver(#37a), if applicable. Overbank Flood Control Criteria(Qp) Pre-Development(CFS) 14.48 Post-Development(CFS) 10.92 Total Extreme Flood Control Criteria(Of) Pre-Development(CFS) 50.17 Post-Development(CFS) 42.10 37a.The need to meet the Qp and Of criteria has been waived because: None Specified 38. Has a long term Operation and Maintenance Plan for the post-construction stormwater management practice(s)been developed? Yes If Yes, Identify the entity responsible for the long term Operation and Maintenance Town drainage district https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 12/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 39. Use this space to summarize the specific site limitations and justification for not reducing 100%of WQv required(#28).(See question#32a)This space can also be used for other pertinent project information. While minimum RRv has been met for this project using grassed filter strips, it is difficult to provide alternative green infrastructure practices in the frontage of this small development. As such, forebays are proposed to treat remaining WQv prior to the capture retention using dry ponds. POST-CONSTRUCTION SMP IDENTIFICATION Runoff Reduction(RR)Techniques,Standard Stormwater Management Practices(SMPs)and Alternative SMPs Identify the Post-construction SMPs to be used by providing the total impervious area that contributes runoff to each technique/practice selected. For the Area Reduction Techniques, provide the total contributing area (includes pervious area) and, if applicable, the total impervious area that contributes runoff to the technique/practice. RR Techniques(Area Reduction) Round to the nearest tenth Total Contributing Acres for Conservation of Natural Area (RR-1) None Specified Total Contributing Impervious Acres for Conservation of Natural Area(RR-1) None Specified Total Contributing Acres for Sheetflow to Riparian Buffers/Filter Strips(RR-2) 3.24 Total Contributing Impervious Acres for Sheetflow to Riparian Buffers/Filter Strips(RR-2) None Specified Total Contributing Acres for Tree Planting/Tree Pit(RR-3) None Specified https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 13/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 Total Contributing Impervious Acres for Tree Planting/Tree Pit(RR-3) None Specified Total Contributing Acres for Disconnection of Rooftop Runoff(RR-4) None Specified RR Techniques(Volume Reduction) Total Contributing Impervious Acres for Disconnection of Rooftop Runoff(RR-4) None Specified Total Contributing Impervious Acres for Vegetated Swale(RR-5) None Specified Total Contributing Impervious Acres for Rain Garden(RR-6) None Specified Total Contributing Impervious Acres for Stormwater Planter(RR-7) None Specified Total Contributing Impervious Acres for Rain Barrel/Cistern(RR-8) None Specified Total Contributing Impervious Acres for Porous Pavement(RR-9) None Specified Total Contributing Impervious Acres for Green Roof(RR-10) None Specified Standard SMPs with RRv Capacity Total Contributing Impervious Acres for Infiltration Trench(1-1) None Specified https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 14/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 Total Contributing Impervious Acres for Infiltration Basin (1-2) None Specified Total Contributing Impervious Acres for Dry Well(1-3) None Specified Total Contributing Impervious Acres for Underground Infiltration System(1-4) None Specified Total Contributing Impervious Acres for Bioretention (F-5) None Specified Total Contributing Impervious Acres for Dry Swale(0-1) None Specified Standard SMPs Total Contributing Impervious Acres for Micropool Extended Detention (P-1) None Specified Total Contributing Impervious Acres for Wet Pond(P-2) None Specified Total Contributing Impervious Acres for Wet Extended Detention(P-3) None Specified Total Contributing Impervious Acres for Multiple Pond System (P-4) None Specified Total Contributing Impervious Acres for Pocket Pond (P-5) 4.72 Total Contributing Impervious Acres for Surface Sand Filter(F-1) None Specified https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 15/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 Total Contributing Impervious Acres for Underground Sand Filter(F-2) None Specified Total Contributing Impervious Acres for Perimeter Sand Filter(F-3) None Specified Total Contributing Impervious Acres for Organic Filter(F-4) None Specified Total Contributing Impervious Acres for Shallow Wetland(W-1) None Specified Total Contributing Impervious Acres for Extended Detention Wetland(W-2) None Specified Total Contributing Impervious Acres for Pond/Wetland System(W-3) None Specified Total Contributing Impervious Acres for Pocket Wetland(W-4) None Specified Total Contributing Impervious Acres for Wet Swale(0-2) None Specified Alternative SMPs(DO NOT INCLUDE PRACTICES BEING USED FOR PRETREATMENT ONLY) Total Contributing Impervious Area for Hydrodynamic None Specified Total Contributing Impervious Area for Wet Vault None Specified Total Contributing Impervious Area for Media Filter None Specified https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 16/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 "Other"Alternative SMP? None Specified Total Contributing Impervious Area for"Other" None Specified Provide the name and manufaturer of the alternative SMPs(i.e. proprietary practice(s)) being used for WQv treatment. Note: Redevelopment projects which do not use RR techniques, shall use questions 28, 29, 33 and 33a to provide SMPs used,total WQv required and total WQv provided for the project. Manufacturer of Alternative SMP None Specified Name of Alternative SMP None Specified OTHER PERMITS 40. Identify other DEC permits, existing and new,that are required for this project/facility. None If SPDES Multi-Sector GP,then give permit ID None Specified If Other,then identify None Specified 41. Does this project require a US Army Corps of Engineers Wetland Permit? No If"Yes,"then indicate Size of Impact, in acres,to the nearest tenth None Specified https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 17/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 42. If this N01 is being submitted for the purpose of continuing or transferring coverage under a general permit for stormwater runoff from construction activities, please indicate the former SPDES number assigned. None Specified MS4 SWPPP ACCEPTANCE 43. Is this project subject to the requirements of a regulated,traditional land use control MS4? Yes - Please attach the MS4 Acceptance form below If No,skip question 44 44. Has the"MS4 SWPPP Acceptance"form been signed by the principal executive officer or ranking elected official and submitted along with this N01? None Specified MS4 SWPPP Acceptance Form Download Download form from the link below. Complete, sign, and upload. MS4 SWPPP Acceptance Form MS4 Acceptance Form Upload No files uploaded Comment None Specified OWNER/OPERATOR CERTIFICATION The owner/operator must download, sign, and upload the certification form in order to complete this application. https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 18/19 12/3/2020 NYSDEC eBusiness Portal System-NOI-Britton Subdv. Revision 1 Owner/Operator Certification Form Download Download the certification form by clicking the link below. Complete, sign, scan, and upload the form. Owner/Operator Certification Form (PDF, 45KB) Upload Owner/Operator Certification Form No files uploaded Comment At least one file is required. None Specified https://nform-prod.dec.ny.gov/app/#/submissionwizard/02a9395c-7980-4399-a7b8-e8e3e3a7c247/11 19/19 NEWYORK Departmentof STATE OF OPPORTUNITY Environmental Conservation Owner/Operator Certification Form SPDES General Permit For Stormwater Discharges From Construction Activity (GP-0-20-001) Project/Site Name: Britton Woods Subdivision eN01 Submission Number: H PO-2901 -2k6PN eN01 Submitted by: Owner/Operator Fv-] SWPPP Preparer Other Certification Statement - Owner/Operator I have read or been advised of the permit conditions and believe that I understand them. I also understand that, under the terms of the permit, there may be reporting requirements. I hereby certify that this document and the corresponding documents were prepared under my direction or supervision. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. I further understand that coverage under the general permit will be identified in the acknowledgment that I will receive as a result of submitting this NOI and can be as long as sixty (60) business days as provided for in the general permit. I also understand that, by submitting this NOI, I am acknowledging that the SWPPP has been developed and will be implemented as the first element of construction, and agreeing to comply with all the terms and conditions of the general permit for which this NOI is being submitted. Owner/Operator First Name M.I. Last Name Signature Date New York State Department of Environmental Conservation Division of Water 625 Broadway,4th Floor Albany,New York 12233-3505 MS4 Stormwater Pollution Prevention Plan (SWPPP) Acceptance Form for construction Activities Seeking Authorization Under SPDES General Permit *(NOTE: Attach Completed Forth to Notice Of Intent and Submit to Address Above) I.Project Owner/Operator Information 1. Owner/Operator Name: 2. Contact Person: 3. Street Address: 4.City/State/Zip: H.Project Site Information 5.Project/Site Name: 6. Street Address: 7. City/State/Zip: III.Stormwater Pollution Prevention Plan(SWPPP)Review and Acceptance Information 8. SWPPP Reviewed by: 9.Title/Position: 10.Date Final SWPPP Reviewed and Accepted: IV.Regulated MS4 Information 11.Name of MS4: 12.MS4 SPDES Permit Identification Number:NYR20A 13. Contact Person: 14. Street Address: 15. City/State/Zip: 16.Telephone Number: MS4 SWPPP Acceptance Form -continued V.Certification Statement-MS4 Official(principal executive officer or ranking elected official)or Duly Authorized Representative I hereby certify that the final Stormwater Pollution Prevention Plan(SWPPP)for the construction project identified in question 5 has been reviewed and meets the substantive requirements in the SPDES General Permit For Stormwater Discharges from Municipal Separate Storm Sewer Systems(MS4s).Note:The MS4,through the acceptance of the SWPPP,assumes no responsibility for the accuracy and adequacy of the design included in the SWPPP.In addition,review and acceptance of the SWPPP by the MS4 does not relieve the owner/operator or their SWPPP preparer of responsibility or liability for errors or omissions in the plan. Printed Name: Title/Position: Signature: Date: VI.Additional Information Attachment B: Notice of Termination, (NOT) AmYork State Department of Environmental Conservation Am Division of Water _ 625 Broadway,4th Floor Albany,New York 12233-3505 *(NOTE:Submit completed form to address above)* NOTICE OF TERMINATION for Storm Water Discharoes :authorized under the SPDES General Permit for Construction :kcti%it,* Please indicate your permit identification number: NYK 1. O«ner or Operator Information 1.Owner/Operator Name: 2.Street Address: 3.City/State/Zip: 4.Contact Person: 4a.Telephone: 5.Contact Person E-Mail: II. Project Site Information 5.Project/Site Name: 6.Street Address: 7.City/Zip: 8.County: III. Reason for Termination 9a. L All disturbed areas have achieved final stabilization in accordance with the general permit and SWPPP. *Date final stabilization completed(month/year): 9b.L Permit coverage has been transferred to new owner/operator. Indicate new owner/operator's permit identification number:NYR (Note:Permit coverage can not be terminated by owner identified in 1.1.above until new owner/operator obtains coverage under the general permit) 9c. ❑Other(Explain on Page 2) IV. Final Site Information: I Oa. Did this construction activity require the development of a SWPPP that includes post-construction stormwater management practices? ❑yes ❑no (If no,go to question 1 Of.) 10b.Have all post-construction stormwater management practices included in the final SWPPP been constructed? ❑yes I I no (If no,explain on Page 2) 1 Oc.Identify the entity responsible for long-term operation and maintenance of practice(s)? Page 1 of 3 NOTICE OF TERMINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity-continued I ud.Has the entity responsible for long-term operation and maintenance been given a copy of the operation and maintenance plan required by the general permit? C yes U no I He. Indicate the method used to ensure long-term operation and maintenance of the post-construction stormwater management practice(s): U Post-construction stormwater management practice(s)and any right-of-ways)needed to maintain practice(s)have been deeded to the municipality. 1 Executed maintenance agreement is in place with the municipality that will maintain the post-construction stormwater management practice(s). For post-construction stormwater management practices that are privately owned,the deed of record has been modified to include a need covenant that requires operation and maintenance of the practice(s)in accordance with the operation and maintenance plan. C For post-construction stormwater management practices that are owned by a public or private institution (e.g.school,college,university),or govenument agency or authority,policy and procedures are in place that ensures operation and maintenance of the practice(s)in accordance with the operation and maintenance plan. I Of. Provide the total area of impervious surface(i.e.roof,pavement,concrete,gravel,etc.)constructed within the disturbance;area? (acres) 1 1.Is this project subject to the requirements of a regulated,traditional land use control MS4? ❑yes I i no (If Yes,complete section VI-"MS4 Acceptance"statement V. Additional Information/Explanation: (Use this section to answer questions 9c. and 10b.,if applicable) N't. NM Acceptance-MS4 Official(principal executive officer or ranking elected official)or Duly Authorized Representative(Mote:Not required when 9b. is checked-transfer of coverage) I Dave determined that it is acceptable for the owner or operator of the construction project identified in question submit the Notice of Termination at this time. 1'rinted Name: I-itleiPosition: Si-onature: Date: Page 2 of 3 NOTICE OF TERNIINATION for Storm Water Discharges Authorized under the SPDES General Permit for Construction Activity-continued NTI. Qualified Inspector Certification-Final Stabilization: I hereby certify that all disturbed areas have achieved final stabilization as defined in the current version of the general permit,and that all temporary,structural erosion and sediment control measures have been removed. Furthermore,I understand that certifying false,incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal,civil and/or administrative proceedings. Printed Name: Title/Position: 7 ignature: Date: 17III. Qualified Inspector Certification-Post-construction Storm water Management Practice(%): I hereby certify that all post construction stormwater management practices have been constructed in conformance with the SWPPP. Furthermore,I understand that certifying false, incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal,civil and/or administrative proceedings. Printed Name: Title/Position: Signature: Date: IX. Owner or Operator Certification I hereby certify that this document was prepared by me or under my direction or supervision.My determination based upon my inquiry of the person(s)who managed the construction activity,or those persons directly responsible for gathering the information,is that the information provided in this document is true,accurate and complete. Furthermore,I understand that certifying,false,incorrect or inaccurate information is a violation of the referenced permit and the laws of the State of New York and could subject me to criminal,civil and/or administrative proceedings. Printed Name: Title/Position: Si nature: Date: (NYS DEC Notice of Termination-January 2010) Page 3 of 3 Attachment C: Certification Forms CONTRACTOR and SUBCONTRACTOR CERTIFICATION STATEMENT for the New York State Department of Environmental Conservation (DEC) State Pollutant Discharge Elimination System Permit for Stormwater Discharges from Construction Activity (GP-0-10-001) As per Part X.A.6 on page 13 of GP-0-10-001 (effective January 29, 2010): `Prior to the commencement of construction activity, the owner or operator must identify the contractor(s) and subcontractor(s) that will be responsible for installing, constructing, repairing, replacing, inspecting and maintaining the erosion and sediment control practices included in the SWPPP; and the contractor(s) and subcontractor(s) that will be responsible for constructing the post- construction stormwater management practices included in the SWPPP. The owner or operator shall have each of the contractors and sub-contractors identify at least one person from their company that will be responsible for implementation of the SWPPP. This person shall be known as the trained contractor. The owner or operator shall ensure that at least one trained contractor is on site on a daily basis when soil disturbance activities are being performed.' The owner or operator shall have each contractor and subcontractor involved in soil disturbance sign a copy of the following certification statement before they commence any construction activity: NYR Name of Construction Site DEC Permit ID Municipality (MS4) "I hereby certify that I understand and agree to comply with the terms and conditions of the SWPPP and agree to implement any corrective actions identified by the qualified inspector during a site inspection. I also understand that the owner or operator must comply with the terms and conditions of the most current version of the New York State Pollutant Discharge Elimination System ("SPDES')general permit for stormwater discharges from construction activities and that it is unlawful for any person to cause or contribute to a violation of water quality standards. Furthermore, I understand that certifying false, incorrect or inaccurate information is a violation of the referencedpermit and the laws of the State of New York and could subject me to criminal, civil and/or administrative proceedings. Responsible Corporate Officer/Partner Signature Date Name of above Signatory Name of Company Title of above Signatory Mailing Address Telephone of Company City, State and Zip Identify the specific elements of the SWPPP the contractor or subcontractor is responsible for: `TRAINED CONTRACTOR'FOR THE CERTIFIED CONTRACTOR OR SUBCONTRACTOR Name of Trained Employee Title of Trained Employee NYSDEC SWT# A copy of this signed contractor certification statement must be maintained at the SWPPP on site Attachment D: State Historic Preservation Mapping Cultural Resource Information System(CRIS) https:Hcris.parks.ny.gov/ CRISHOME SUBMIT SEARCH COMMUNICATE Criteria Spotltal Results + _L^ Building1 Results Found Surveys Y ( ) Download Results I t View Zoom Number Name - > 19SR00506 WOMEN'S SUFFRAGE IN CENTRAL NEW YORK Terpening — vwu�lrI.Rd "EI �u South LanSIMW Aubuln U- coril e7'S - 11 � I f r O Ft AcrA<lyer I1r C n I ro o n � an cata Ar a 'Or I 8 4 a a e e O Asbu m 9� Po I r W'µend—Or E Meadow Or Rd Asbury Of S ti Qr tia 8 4 ;... 'e lgjet O&V Ln R n L Cf cJ� C w�Y 0. k GNaveM1 WaTurw _ aeon Ra - p 0 CLI 0.�E _ Arrowood Ln s n _ County of Tompkins,EA.HERE 1 of 1 9/20/2019, 10:50 AM Attachment E: Environmental Mapping Environmental Resource Mapper http://www.dec.ny.gov/gis/erm/ .• , WMEMMOromn Environmental Resource Mapper Base Map: Topographical Using this map Search Tools Layers and Legend �J All Layers — u i I - F, I ®*Unique Geological Features ® Waterbody Classifications for Rivers/Streams 0 � d Waterbody Classifications for Lakes ® State Regulated Freshwater Wetlands i� lea- I I I F LI State Regulated Wetland Checkzone 0 B 0 Significant Natural Communities a l ®Natural Communities Near This Location 9 Rare Plants or Animals I t , Other Wetland Layers s� Reference Layers Tell Me More... \ - II� 3s Need APermit? _ 10 Contacts o. \tso aoort - - ----- -- -----" - � __ roea— — Asb�,y� u -I - .I 1 of 2 9/20/2019, 10:52 AM Environmental Resource Mapper http://www.dec.ny.gov/gis/erm/ 2 of 2 9/20/2019, 10:52 AM Attachment F: Inspection Report (Sample Form) TOWN OF Construction Stormwater Inspection Report for SPDES General Permit GP-0-15-002 Project Name arid Location: Date: _F­thcr: Permit#(if any): NYR10 Municipality: County: Entry Time: Exit Time: Name of SPDES Permittee: Contacted: YesE] NoD Inspection Type. Phone Number: [:]Compliancc, OReftmilaOMPIRIT11 On-site Representatives)and Company(s): Phone Number(s): SPDES Authorl(y Yes No NIA 1. E] ❑ 0 Does the project have permit coverage? 2. Is a copy of the NOI and Acknowledgment Letter available,on site and accessible for viewing? 3. Is a copy of the MS4 SWPPP Acceptance Form available on site and accessible for viewing? 4. Is an up-to-date copy of the signed SWPPP retained at the construction site? 5. Is a copy of the SPDES General Permit retained a[the construction site? 6. 0 Does the NOI accurately report the number of acres to be disturbed? SNVT-IPP Content Yes No NA 7- 1:1 El 0 Does the SWPPP describe and identify the erosion and sediment control measures to be employed? S. [] [] [] Does the SWPPP provide an inspect-ion schedule and maintenance requirements for the E&SC measures? 9. [:] [3 '' Does the SWPPP describe and identify the stormwater management practices to be employed? 10.Ll [:1 [3 Does the SWPPP identify the contractor(s)and subcontractor(s)responsible for each measure? 11.[:] El [I Does the SWPPP identify at leas[one trained individual from each contractors)and subcolitractor(s)companies 12.El [I [] Does the SWPPP include all the necessary Contractor Certification Statements and signatures? 13.E] E] E] Is the SWPPP signed by the permittre? 14.[:] Q El Is the SWPPP prepared by a qualified professional(if post-construction stormwater management required)? 15-E] [] E] Do the SNIPs conform to the Enhanced Phosphorus Removal Standards(projects in TMDL watersheds)? Recordkeephip- Yes No N/A 16.[:] Are self inspections performed as required by the permit(weekly,or twice weekly for>5 acres disturbed)? 17.D Are the self-inspections performed by and signed by a qualified inspector and retained on site? 18.E] E] ❑ Do the qualified inspector's reports include the minimum reporting requirements? o.E] El El Do inspection reports identify corrective mea�nrcs that have not been implemented or are recurring? Visual Observations Yes No NIA 20.El El El Are all erosion and sediment contra[measures installed properly? 21.El [:3 [1 Are all erosion and sediment control measures being maintained properly? 22.0 0 0 Was written authorization issued for any disturbance greater than 5 acres? 23.El D 0 Have stabilization measures been implemented in inactive areas per Permit(>5 acres)and E&.SC Standards? 24J] ❑ [] Are post-construction storrawater management practices constructed/installed correctly? 25.[:] ❑ 0 Has final site stabilization been achieved and temporary E&SC measures removed prior to NOT submittal? 26.0 [1 0 Was there a discharge from the site on the day of inspection? 27.E] E] [:] Is there evidence that a discharge caused or contributed to a violation of water quality standards? Pk�e I of 2 Page 2 of 2 Water Oualltar Observat.lons Describe the discharge(s):location,source(s),impact on receiving water(s),etc. Describe the quality of the receiving water(s)both upstream and downstream of the discharge Describe any tither water quality standards or permit violations Additional Comments 17 Photographs attached Overall Inspection Rating: ❑satisfactory Dmarginal ®Unsatisfactory S' ature of Lead Inspector:f Il Inspector: Names'Agencles of Other Inspectors: Attachment G: Record of Stabilization and Construction Activity Dates (Sample Form) SITE STABILIZATION and CONSTRUCTION ACTIVITY DATES A record of dates when major grading activities occur, when construction activities temporarily or permanently cease on a portion of the site, and when stabilization measures are initiated shall be maintained until final site stabilization is achieved and the Notice of Termination is filed. The dates can be entered in the following form, or on a different form. MAJOR GRADING ACTIVITIES: Description of Activity: Begin(date): Site Contractor: Location: End(date): Description of Activity: Begin(date): Site Contractor: Location: End (date): Description of Activity: Begin(date): Site Contractor: Location: End(date): Description of Activity: Begin(date): Site Contractor: Location: End(date): Description of Activity: Begin(date): Site Contractor: Location: End(date): Description of Activity: Begin(date): Site Contractor: Location: End(date): Description of Activity: Begin (date): Site Contractor: Location: End(date): Attachment H: Vegetative and Structural Measures For Erosion and Sediment Control (NYS Standards & Specifications for Erosion & Sediment Control) (Reference) STANDARD AND SPECIFICATIONS FOR MULCHING Remove all undesirable stones and other debris to meet the needs of the anticipated land use and maintenance required. Apply mulch after soil amendments and planting is accomplished or simultaneously if hydroseeding is used. o- Select appropriate mulch material and application rate or material needs. Hay mulch shall not be used in wetlands or in areas of permanent seeding. Clean straw mulch is preferred alternative in wetland application. Determine local availability. Definition and Scope Select appropriate mulch anchoring material. Applying coarse plant residue or chips,or other suitable NOTE: The best combination for grass/legume materials,to cover the soil surface to provide initial erosion establishment is straw(cereal grain)mulch applied at 2 ton/ control while a seeding or shrub planting is establishing. acre(90 lbs./1000sq.ft.)and anchored with wood fiber Mulch will conserve moisture and modify the surface soil mulch(hydromulch)at 500—750 lbs./acre(11— 17 temperature and reduce fluctuation of both. Mulch will lbs./l000 sq.ft.). The wood fiber mulch must be applied prevent soil surface crusting and aid in weed control.Mulch through a hydroseeder immediately after mulching. can also be used alone for temporary stabilization in non- growing months. Use of stone as a mulch could be more permanent and should not be limited to non-growing months. Conditions Where Practice Applies On soils subject to erosion and on new seedings and shrub plantings. Mulch is useful on soils with low infiltration rates by retarding runoff. Criteria Site preparation prior to mulching requires the installation of necessary erosion control or water management practices and drainage systems. Slope,grade and smooth the site to fit needs of selected mulch products. New York State Standards and Specifications Page 4.39 November 2016 For Erosion and Sediment Control z 0 CD a Mulch Quality Depth of n, Material Standards per 1000 Sq.Ft. per Acre Application Remarks 0 Wood chips or Air-dried. Free of 500-900 lbs. 10-20 tons 2-7" Used primarily around shrub and tree shavings objectionable coarse plantings and recreation trails to inhibit material weed competition. Resistant to wind blowing.Decomposes slowly. Wood fiber cellulose Made from natural wood 50 lbs. 2,000 lbs. — Apply with hydromulcher. No tie down . (partly digested usually with green dye required. Less erosion control provided ¢ wood fibers) and dispersing agent than 2 tons of hay or straw. Gravel,Crushed Washed; Size 2B or 9 cu.yds. 405 cu.yds. Excellent mulch for short slopes and C Stone or Slag 3A-1 1/2" around plants and ornamentals. Use 2B where subject to traffic. (Approximately C 2,000 lbs./cu.yd.). Frequently used over n filter fabric for better weed control. Hay or Straw Air-dried;free of 90-100 lbs.2-3 bales 2 tons(100- cover about 90% Use small grain straw where mulch is undesirable seeds& 120 bales) surface maintained for more than three months. �.r G coarse materials Subject to wind blowing unless anchored. p Most commonly used mulching material. Provides the best micro-environment for N germinating seeds. Jute twisted yarn Undyed,unbleached 48"x 50 yds.or 48" Use without additional mulch. Tie down plain weave. Warp 78 x 75 yds. as per manufacturers specifications. z ends/yd.,Weft 41 ends/ Good for center line of concentrated yd.60-90 lbs./roll water flow. o � Excelsior wood fiber Interlocking web of 4'x 112.5'or 8'x — Use without additional mulch. Excellent omats excelsior fibers with 112.5'. for seeding establishment. Anchor as per M CD photodegradablc plastic manufacturers specifications. VA netting Approximately 72 lbs./roll for excelsior with plastic on both sides. Use two sided n plastic for centerline of waterways. a " c Straw or coconut Photodegradable plastic Most are 6.5 ft.x 3.5 81 rolls Designed to tolerate higher velocity water CL fiber,or net on one or two sides ft. flow,centerlines of waterways,60 sq. 173 CD combination yds.per roll. C) o o w o � Table 4.3 Mulch Anchoring Guide Anchoring Method Kind of Mulch to or Material be Anchored How to Apply After mulching,divide areas into blocks approximately 1 sq. yd.in size. Drive 4-6 pegs per block to within 2"to 3"of soil 1. Peg and Twine Hay or straw surface. Secure mulch to surface by stretching twine between pegs in criss-cross pattern on each block. Secure twine around each peg with 2 or more tight turns. Drive pegs flush with soil. Driving stakes into ground tightens the twine. Staple the light-weight paper,jute,wood fiber,or plastic 2. Mulch netting Hay or straw nettings to soil surface according to manufacturer's recommendations. Should be biodegradable. Most products are not suitable for foot traffic. Apply with hydroseeder immediately after mulching. Use 500 3. Wood cellulose fiber Hay or straw lbs.wood fiber per acre. Some products contain an adhesive material("tackifier"),possibly advantageous. Apply mulch and pull a mulch anchoring tool(blunt, straight 4. Mulch anchoring tool Hay or straw discs)over mulch as near to the contour as possible. Mulch material should be"tucked"into soil surface about 3". Mix and apply polymeric and gum tackifiers according to 5. Tackifier Hay or straw manufacturer's instructions. Avoid application during rain.oA 24-hour curing period and a soil temperature higher than 45 Fahrenheit are required. New York State Standards and Specifications Page 4.41 November 2016 For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR PERMANENT CONSTRUCTION AREA PLANTING Y� ground agricultural limestone to attain a pH of 6.0 in the upper 2 inches of soil. If soil must be fertilized before results of a soil test can be obtained to determine fertilizer a+ ' needs,apply commercial fertilizer at 600 lbs.per acre of 5-5 -10 or equivalent. If manure is used,apply a quantity to meet the nutrients of the above fertilizer. This requires an appropriate manure analysis prior to applying to the site. a_ Do not use manure on sites to be planted with birdsfoot trefoil or in the path of concentrated water flow. Seed mixtures may vary depending on location within the state and time of seeding. Generally,warm season grasses should only be seeded during early spring,April to May. These grasses are primarily used for vegetating excessively drained sands and gravels. See Standard and Specification Definition & Scope for Sand and Gravel Mine Reclamation. Other grasses may be seeded any time of the year when the soil is not frozen Establishing permanent grasses with other forbs and/or and is workable. When legumes such as birdsfoot trefoil shrubs to provide a minimum 80%perennial vegetative are included, spring seeding is preferred. See Table 4.4, cover on areas disturbed by construction and critical areas "Permanent Construction Area Planting Mixture to reduce erosion and sediment transport. Critical areas Recommendations"for additional seed mixtures. may include but are not limited to steep excavated cut or fill slopes as well as eroding or denuded natural slopes and areas subject to erosion. General Seed Mix: Variety lbs./ lbs/1000 acre sq.It. Conditions Where Practice Applies Red Clovers OR Acclaim,Rally, 8 0?0 This practice applies to all disturbed areas void of,or Red Head II, having insufficient,cover to prevent erosion and sediment Renegade transport. See additional standards for special situations Common white clovers Common 0?0 such as sand dunes and sand and gravel pits. PLUS Criteria Creeping Red Fescue Common 20 0.45 All water control measures will be installed as needed prior PLUS to final grading and seedbed preparation. Any severely Smooth Bromegrass 2 0.05 compacted sections will require chiseling or disking to OR Common provide an adequate rooting zone,to a minimum depth of 12",see Soil Restoration Standard. The seedbed must be Ryegrass(perennial) Pennfinc/Linn 5 0.10 prepared to allow good soil to seed contact,with the soil not s too soft and not too compact. Adequate soil moisture must z add inoculant immediately prior to seeding be present to accomplish this. If surface is powder dry or Mix 41bs each of Empire and Pardee OR 4 lbs of sticky wet,postpone operations until moisture changes to a Birdsfoot and 41bs white clover per acre. All seeding rates favorable condition. If seeding is accomplished within 24 1 are given for Pure Live Seed(PLS) hours of final grading,additional scarification is generally not needed,especially on ditch or stream banks. Remove pine Live Seed,or(PLS)refers to the amount of live seed all stones and other debris from the surface that are greater in a lot of bulk seed. Information on the seed bag label than 4 inches,or that will interfere with future mowing or includes the type of seed,supplier,test date,source of seed, maintenance. purity,and germination. Purity is the percentage of pure Soil amendments should be incorporated into the upper 2 seed. Germination is the percentage of pure seed that will inches of soil when feasible. The soil should be tested to produce normal plants when planted under favorable determine the amounts of amendments needed. Apply conditions. November 2016 Page 4.42 New York State Standards and Specifications For Erosion and Sediment Control ��•hA To compute Pure Live Seed multiply the"germination percent"times the"purity"and divide that by 100 to get Pure Live Seed. A PoreLWeSeedMA)=%Garmin@timx%Ptuit7r 100 WA For example,the PLS for a lot of Kentucky Blue grass with 75%purity and 96%germination would be calculated as follows: (96) (75) ue A& I00 —72%A Live Sad 4� 711 For 1 Olbs of PLS from this lot= ► 10=139Pm 80%Perennial Vegetative Cover 0.72 Therefore, 13.9 lbs of seed is the actual weight needed to meet l Olbs PSL from this specific seed lot. Time of Seeding: The optimum timing for the general seed mixture is early spring. Permanent seedings may be made any time of year if properly mulched and adequate moisture is provided. Late June through early August is not a good time to seed,but may facilitate covering the land without additional disturbance if construction is completed. Portions of the seeding may fail due to drought and heat. These areas may need reseeding in late summer/fall or the following spring. Method of seeding: Broadcasting,drilling,cultipack type seeding,or hydroseeding are acceptable methods. Proper soil to seed contact is key to successful seedings. Mulching: Mulching is essential to obtain a uniform stand of seeded plants. Optimum benefits of mulching new seedings are obtained with the use of small grain straw 50%Perennial Vegetative Cover applied at a rate of 2 tons per acre,and anchored with a netting or tackifier. See the Standard and Specifications for Mulching for choices and requirements. Irrigation: Watering may be essential to establish a new seeding when a drought condition occurs shortly after a new seeding emerges. Irrigation is a specialized practice and care must be taken not to exceed the application rate for the soil or subsoil. When disconnecting irrigation pipe,be sure pipes are drained in a safe manor,not creating an erosion concern. New York State Standards and Specifications Page 4.43 November 2016 For Erosion and Sediment Control Table 4.4 Permanent Construction Area Planting Mixture Recommendations Seed Mixture Variety Rate in Ibs./acre Rate in lbs./ (PLS) 1,000 ft Mix#1 Creeping red fescue Ensylva,Pennlawn,Boreal 10 .25 Perennial ryegrass Pennfine,Linn 10 .25 *This mix is used extensively for shaded areas. Mix#2 Switchgrass Shelter,Pathfinder,Trailblazer,or Blackwell 20 .50 *This rate is in pure live seed,this would be an excellent choice along the upland edge of a wetland to filter runoff and pro- vide wildlife benefits. In areas where erosion may be a problem,a companion seeding of sand lovegrass should be added to provide quick cover at a rate of 2 lbs.per acre(0.05 lbs.per 1000 sq.ft.). Mix#3 Switchgrass Shelter,Pathfinder,Trailblazer,or Blackwell 4 .10 Big bluestem Niagara 4 .10 Little bluestem Aldous or Camper _' .05 Indiangrass Rumsey ' .10 Coastal panicgrass Atlantic ? .05 Sideoats grama El Reno or Trailway .05 Wildflower mix .50 .01 *This mix has been successful on sand and gravel plantings. It is very difficult to seed without a warm season grass seeder such as a Truax seed drill. Broadcasting this seed is very difficult due to the fluffy nature of some of the seed,such as bluestems and indiangrass. Mix#4 Switchgrass Shelter,Pathfinder,Trailblazer,or Blackwell 10 .25 Coastal panicgrass Atlantic 10 .25 *This mix is salt tolerant,a good choice along the upland edge of tidal areas and roadsides. Mix#5 Saltmeadow cordgrass(Spartina patens)--This grass is used for tidal shoreline protection and tidal marsh restoration. It is planted by vegetative stem divisions. 'Cape'American beachgrass can be planted for sand dune stabilization above the saltmeadow cordgrass zone. Mix#6 Creeping red fescue Ensylva,Pennlawn,Boreal 20 .45 Chewings Fescue Common 20 .45 Perennial ryegrass Pennfine,Linn 5 .10 Red Clover Common 10 .45 *General purpose erosion control mix. Not to be used for a turf planting or play grounds. November 2016 Page 4.44 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TEMPORARY CONSTRUCTION AREA SEEDING Criteria Water management practices must be installed as appropriate for site conditions. The area must be rough _ - graded and slopes physically stable. Large debris and rocks _ are usually removed. Seedbed must be seeded within 24 hours of disturbance or scarification of the soil surface will be necessary prior to seeding. Fertilizer or lime are not typically used for temporary " seedings. -� - IF: Spring or summer or early fall,then seed the area with f - ryegrass(annual or perennial)at 30 lbs.per acre Definition & Scope (Approximately 0.7 lb./1000 sq.ft.or use 1 lb./1000 sq.ft.). IF: Late fall or early winter,then seed Certified Providing temporary erosion control protection to disturbed `Aroostook'winter rye(cereal rye)at 100 lbs.per acre(2.5 areas and/or localized critical areas for an interim period by lbs./1000 sq.ft.). covering all bare ground that exists as a result of construction activities or a natural event. Critical areas may Any seeding method may be used that will provide uniform include but are not limited to steep excavated cut or fill application of seed to the area and result in relatively good slopes and any disturbed,denuded natural slopes subject to soil to seed contact. erosion. Mulch the area with hay or straw at 2 tons/acre(approx.90 Conditions Where Practice Applies lbs./1000 sq.ft. or 2 bales). Quality of hay or straw mulch allowable will be determined based on long term use and Temporary seedings may be necessary on construction sites visual concerns. Mulch anchoring will be required where to protect an area,or section,where final grading is wind or areas of concentrated water are of concern. Wood complete,when preparing for winter work shutdown,or to fiber hydromulch or other sprayable products approved for provide cover when permanent seedings are likely to fail erosion control(nylon web or mesh)may be used if applied due to mid-summer heat and drought. The intent is to according to manufacturers' specification. Caution is provide temporary protective cover during temporary advised when using nylon or other synthetic products. They shutdown of construction and/or while waiting for optimal may be difficult to remove prior to final seeding and can be planting time. a hazard to young wildlife species. November 2016 Page 4.58 New York State Standards and Specifications For Erosion and Sediment Control STANDARD AND SPECIFICATIONS FOR TOPSOILING Site Preparation 1. As needed,install erosion and sediment control practices such as diversions,channels,sediment traps, - and stabilizing measures,or maintain if already installed. 2. Complete rough grading and final grade,allowing for depth of topsoil to be added. 3. Scarify all compact,slowly permeable,medium and fine textured subsoil areas. Scarify at approximately right angles to the slope direction in soil areas that are steeper than 5 percent.Areas that have been overly compacted shall be decompacted in accordance with the Soil Restoration Standard. 4. Remove refuse,woody plant parts,stones over 3 inches in diameter,and other litter. Definition & Scope Topsoil Materials Spreading a specified quality and quantity of topsoil 1. Topsoil shall have at least 6 percent by weight of fine materials on graded or constructed subsoil areas to provide textured stable organic material,and no greater than 20 acceptable plant cover growing conditions,thereby percent. Muck soil shall not be considered topsoil. reducing erosion;to reduce irrigation water needs;and to reduce the need for nitrogen fertilizer application. 2. Topsoil shall have not less than 20 percent fine textured material(passing the NO.200 sieve)and not more than Conditions Where Practice Applies 15 percent clay. Topsoil is applied to subsoils that are droughty(low 3. Topsoil treated with soil sterilants or herbicides shall available moisture for plants),stony,slowly permeable, be so identified to the purchaser. salty or extremely acid. It is also used to backfill around 4. Topsoil shall be relatively free of stones over 1 1/2 shrub and tree transplants.This standard does not apply to inches in diameter,trash,noxious weeds such as nut wetland soils. sedge and quackgrass,and will have less than 10 percent gravel. Design Criteria 5. Topsoil containing soluble salts greater than 500 parts 1. Preserve existing topsoil in place where possible, per million shall not be used. thereby reducing the need for added topsoil. 6. Topsoil may be manufactured as a mixture of a mineral 2. Conserve by stockpiling topsoil and friable fine component and organic material such as compost. textured subsoils that must be stripped from the Application and Grading excavated site and applied after final grading where vegetation will be established. Topsoil stockpiles must 1. Topsoil shall be distributed to a uniform depth over the be stabilized. Stockpile surfaces can be stabilized by area. It shall not be placed when it is partly frozen, vegetation,geotextile or plastic covers. This can be muddy,or on frozen slopes or over ice,snow,or aided by orientating the stockpile lengthwise into standing water puddles. prevailing winds. 2. Topsoil placed and graded on slopes steeper than 5 3. Refer to USDA Natural Resource Conservation Service percent shall be promptly fertilized,seeded,mulched, soil surveys or soil interpretation record sheets for and stabilized by"tracking"with suitable equipment. further soil texture information for selecting appropriate design topsoil depths. 3. Apply topsoil in the amounts shown in Table 4.7 below: New York State Standards and Specifications Page 4.59 November 2016 For Erosion and Sediment Control Table 4.7 - Topsoil Application Depth Minimum Site Conditions Intended Use Topsoil Depth 1.Deep sand or Mowed lawn 6 in. loamy sand Tall legumes,unmowed 2 in. Tall grass,unmowed 1 in. 2.Deep sandy Mowed lawn 5 in. loam Tall legumes,unmowed 2 in. Tall grass,unmowed none 3.Six inches or Mowed lawn 4 in. more: silt loam, clay loam,loam, Tall legumes,unmowed 1 in. or silt Tall grass,unmowed 1 in. November 2016 Page 4.60 New York State Standards and Specifications For Erosion and Sediment Control STRUCTURAL MEASURES FOR EROSION AND SEDIMENT CONTROL General minimize the amount of sediment that is produced. In general,it is advantageous to clear only as much area as is Uncontrolled runoff and excess erosion often occurs in necessary to accommodate construction needs. Grade and urban developments,particularly during the construction stabilize large sites in stages whenever possible. Limiting stage. This erosion forms rills and gullies;washes out the amount of disturbed area limits the amount of sediment roads; scours cut and fill areas;fills road ditches, storm that is generated,thus decreasing the amount of drains,and streams; and does other damage that is costly to maintenance required on sediment control measures. the developers and damaging to land and water users below. Careful inclusion of proven conservation practices in the Sediment generated during the construction of cut and fill development plan can prevent or alleviate much of this slopes can also be minimized through design and grading damage and should be a part of every development plan. techniques. When designing either a cut or fill slope, factors to consider include slope length and steepness,soil These practices will usually be a combination of vegetative type,and upslope drainage area. In general,it is important and structural measures. They may be temporary and serve to leave soil surfaces on disturbed slopes in a roughened only during the construction stage or they may be condition and to construct a water diversion practice at the permanent in nature and become a part of the completed top of slopes. Rough soil surfaces do not erode as readily development. Permanent structural practices should be as smooth soil surfaces. installed as early as possible in the construction stage. This section deals with the more common structural measures Although design and grading techniques can reduce soil that may be used. Adequate designs,plans,and erosion,they cannot eliminate it entirely. Therefore, specification should be prepared for the measures to be practices must be installed to prevent offsite sedimentation. used. A number of measures and specifications are included throughout this section. The designer shall Even though the specific conditions of each site determine determine those elements to be installed to control erosion what measures are necessary to control erosion and (Section 2)and follow the criteria included in these sedimentation, some general principles apply to the standards and specifications. selection and placement of sediment control measures. Introduction 1. Prevent clean water from becoming turbid,by diverting runoff from upslope areas away from Structural erosion and sediment control practices have been disturbed areas. Earth dikes,temporary swales, classified as either temporary or permanent,according to perimeter dike/swales,or diversions that outlet in how they are used. Temporary structural practices are used stable areas can be used in this capacity. during construction to prevent offsite sedimentation. The length of time that temporary practices are functional varies 2. Remove sediment from turbid water before the water from project to project,since the sediment control strategy leaves the site. The method of sediment removal. may change as construction activity progresses. Permanent depends upon how the water drains from the site. structural practices are used to convey surface water runoff Concentrated flow must be diverted to a trapping to a safe outlet. Permanent structural practices will remain device so that suspended sediment can be deposited. Dikes or swales that outlet into traps or basins can in place and continue to function after the completion of construction. accomplish this. A storm drain system may be used to convey concentrated sediment laden water only if Regardless of whether the practices are temporary or the system empties into a trap or basin. Otherwise, permanent,runoff control measures should be the first items all storm drain inlets must be protected so that constructed when grading begins,and be completely sediment laden water cannot enter the drainage functional before downslope land disturbance takes place. system before being treated to remove the sediment. Earthen structures such as diversions,dikes,and swales should be stabilized before being considered functional. 3. Surface runoff draining in sheet flow must be Only after the runoff control structures are operational and controlled and treated before the water leaves the sediment control measures are in place,should clearing and site. Straw bale dikes, silt fences, vegetative grading on the rest of the construction site begin. buffer strips can be used to treat sheet flow. While clearing and grading the site,it is important to August 2005 Page 5.1 New York Standards and Specifications For Erosion and Sediment Control All practices designed and implemented must be properly 3. Protect streams from chemicals,fuel,lubricants, maintained in order to remain functional. Sediment sewage,or other pollutants. accumulated in basins and traps must be removed and disposed of in a manner that stabilizes them on the 4. Avoid disposal of fill in floodplains or drainage ways. construction site. This reduces the capacity of these areas to pass flood flows. Other factors should be observed during construction in order to make erosion and sediment control measures more 5. Do not locate sanitary facilities over,or adjacent to, effective in pollution control. waterways,wells,or springs. These are: 6. Locate storage yards and stockpiles where erosion and sediment hazards are slight. Where this is not 1. Sprinkle or apply dust suppressors. Keep dust down possible,apply necessary erosion control practices. to a tolerable limit on construction sites and haul roads. 2. Use temporary bridges or culverts where fording of streams is objectionable. Avoid borrow areas where pollution from this operation is inevitable. New York Standards and Specifications Page 5.2 August 2005 For Erosion and Sediment Control STANDARD SYMBOLS BRANCH PACKING BI' BRUSH LAYER BM_ BRUSH MATTRESS BEM CHECK DAM — � — ► CMNSTR*UCTION 'ROAD STABILIZATION = CR CURB DROP INLET PROTECTION DIVERSION D DUNE STABILIZATION T1S DUST CONTROL EARTH DIME EXCAVATED DROP INLET PROTECTION IER FIBER ROLL �R FILTER FABRIC DROP INLET PROTECTION GRADE STABILIZATION STRUCTURE GRASSED WATERWAY GL ADAPTED FROM DETAILS PROVIDED BY+ USDA - NRCS, NEW YORK STATE DEPARTMENT OF TRANSPnRTATION, STANDARD SYMBOLS NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, NEW YORK STATE SOIL & WATER CCNSERVATI❑N COMMITTEE August 2005 Page 5.3 New York Standards and Specifications For Erosion and Sediment Control STANDARD SYMBOLS (cont'd) LAND GRADING LEVEL SPREADER LINED WATERWAY RR LIVE CRIBWALL LIVE CUTTINGS/LIVE STAKES PLANTING LC/L LIVE FASCINE LL hMULCHING h� OPTIONAL SEDIMENT TRAP DEWATERING DEVICE � PAVED FLUME PERIMETER DIKE OR SWALE PD PERMANENT SEEDING F� PIPE 12UTLET SEDIMENT TRAP Q PIPE SLDPE DRAIN FLEXIBLE PSI) PORTABLE SEDIMENT TANK PROTECTING VEGETATION ADAPTED FROM DETAILS PROVIDED BY, USDA — NRCS, NEW YORK STATE DEPARTMENT OF TRANSPORTATION, � ��'� � vlr ��� NEW PORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, -NEW YORK STATE SOIL L WATER CONSERVATION COMMITTEE New York Standards and Specifications Page 5.4 August 2005 For Erosion and Sediment Control STANDARD SYMBOLS (cont'd) RECREATION AREA IMPROVEMENT �A,I RIP RAP OUTLET PROTECTION RIP RAP SLOPE PROTECTION FLIP RAP STREAMBANK PROTECTION ROCK DAM SEDIMENT BASIN SEDIMENT TRAP SEGMENTED RETAINING WALL. SILT FENCE ■--�� SODDING STABILIZED CDNSTRUCTION ENTRANCE 0--z-0 STONE & BLOCK DROP INLET PROTECTION STRUCTURE STRAW BALE DIKE " SUBSURFACE DRAIN SD:::) SUMP PIT ADAPTED FROM DETAILS PROVIDED DYa USDA - NRCS, NEW YORK STATE DEPARTMENT OF TRANSPORTATION, T��D PAR� SYMBOLS NEW YORK STATE DEPARTMENT OF EN RONRENTAL CONSERVATION, NEW YORK STATE SOIL & WATER CONSER'VATICIN COMMITTEE August 2005 Page 5.5 New York Standards and Specifications For Erosion and Sediment Control STANDARD SYMBOLS (cont'd) SURFACE ROUGHENING I I TEMPORARY SEEDING QD A-2 B-3 TEMPORARY SWALE T13P"SOILING TREE REVETMENT CD TURBIDITY CURTAIN VEGETATED RDCK GABIOiNS 21R WATER BAR \A/ - WATERWAY CROSSING T ADAPTED FROM DETAILS PROVIDED BY[ USDA — NROS, NEW YORK STATE DEPARTMENT OF TRANSPORTATION, ��' T������ SYMBOLS NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION, NEW YORK STATE SOIL & WATER CONSERVATION COMMITTEE New York Standards and Specifications Page 5.6 August 2005 For Erosion and Sediment Control Attachment I: NYSD E C Stormwater Construction Checklists (Sample Form) Appendix F: Construction Inspection Checklists Stormwater/Wetland Pond Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY Pre-Construction/Materials and Equipment Pre-construction meeting Pipe and appurtenances on-site prior to construction and dimensions checked 1. Material (including protective coating, if specified) 2. Diameter 3. Dimensions of metal riser or pre-cast concrete outlet structure 4. Required dimensions between water control structures (orifices, weirs, etc.) are in accordance with approved plans 5. Barrel stub for prefabricated pipe structures at proper angle for design barrel slope 6. Number and dimensions of prefabricated anti-seep collars 7. Watertight connectors and gaskets 8. Outlet drain valve Project benchmark near pond site Equipment for temporary de-watering i F-1 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 2. Subgrade Preparation Area beneath embankment stripped of all vegetation, topsoil, and organic matter 3. Pipe Spillway Installation Method of installation detailed on plans A. Bed preparation Installation trench excavated with specified side slopes Stable, uniform, dry subgrade of relatively impervious material (If subgrade is wet, contractor shall have defined steps before proceeding with installation) Invert at proper elevation and grade B. Pipe placement Metal /plastic pipe 1. Watertight connectors and gaskets properly installed 2. Anti-seep collars properly spaced and having watertight connections to pipe 3. Backfill placed and tamped by hand under"haunches" of pipe 4. Remaining backfill placed in max. 8 inch lifts using small power tamping equipment until 2 feet cover over pipe is reached F-2 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 3. Pipe Spillway Installation Concrete pipe 1. Pipe set on blocks or concrete slab for pouring of low cradle 2. Pipe installed with rubber gasket joints with no spalling in gasket interface area 3. Excavation for lower half of anti-seep collar(s) with reinforcing steel set 4. Entire area where anti-seep collar(s) will come in contact with pipe coated with mastic or other approved waterproof sealant 5. Low cradle and bottom half of anti-seep collar installed as monolithic pour and of an approved mix 6. Upper half of anti-seep collar(s)formed with reinforcing steel set 7. Concrete for collar of an approved mix and vibrated into place (protected from freezing while curing, if necessary) 8. Forms stripped and collar inspected for honeycomb prior to backfilling. Parge if necessary. C. Backfilling Fill placed in maximum 8 inch lifts Backfill taken minimum 2 feet above top of anti- seep collar elevation before traversing with heavy equipment F-3 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 4. Riser I Outlet Structure Installation Riser located within embankment A. Metal riser Riser base excavated or formed on stable subgrade to design dimensions Set on blocks to design elevations and plumbed Reinforcing bars placed at right angles and projecting into sides of riser Concrete poured so as to fill inside of riser to invert of barrel B. Pre-cast concrete structure Dry and stable subgrade Riser base set to design elevation If more than one section, no spalling in gasket interface area; gasket or approved caulking material placed securely Watertight and structurally sound collar or gasket joint where structure connects to pipe spillway C. Poured concrete structure Footing excavated or formed on stable subgrade, to design dimensions with reinforcing steel set Structure formed to design dimensions, with reinforcing steel set as per plan Concrete of an approved mix and vibrated into place (protected from freezing while curing, if necessary) Forms stripped & inspected for"honeycomb" prior to backfilling; parge if necessary F-4 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 5. Embankment Construction Fill material Compaction Embankment 1. Fill placed in specified lifts and compacted with appropriate equipment 2. Constructed to design cross-section, side slopes and top width 3. Constructed to design elevation plus allowance for settlement 6. Impounded Area Construction Excavated /graded to design contours and side slopes Inlet pipes have adequate outfall protection Forebay(s) Pond benches 7. Earth Emergency Spillway Construction Spillway located in cut or structurally stabilized with riprap, gabions, concrete, etc. Excavated to proper cross-section, side slopes and bottom width Entrance channel, crest, and exit channel constructed to design grades and elevations F-5 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY I COMMENTS UNSATISFACTORY B. Outlet Protection A. End section Securely in place and properly backfilled B. Endwall Footing excavated or formed on stable subgrade, to design dimensions and reinforcing steel set, if specified Endwall formed to design dimensions with reinforcing steel set as per plan Concrete of an approved mix and vibrated into place (protected from freezing, if necessary) Forms stripped and structure inspected for "honeycomb" prior to backfilling; parge if necessary C. Riprap apron /channel Apron /channel excavated to design cross- section with proper transition to existing ground Filter fabric in place Stone sized as per plan and uniformly place at the thickness specified 9. Vegetative Stabilization Approved seed mixture or sod Proper surface preparation and required soil amendments Excelsior mat or other stabilization, as per plan F-6 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY/ COMMENTS UNSATISFACTORY 10. Miscellaneous Drain for ponds having a permanent pool Trash rack/anti-vortex device secured to outlet structure Trash protection for low flow pipes, orifices, etc. Fencing (when required) Access road Set aside for clean-out maintenance 11. Stormwater Wetlands Adequate water balance Variety of depth zones present Approved pondscaping plan in place Reinforcement budget for additional plantings Plants and materials ordered 6 months prior to construction Construction planned to allow for adequate planting and establishment of plant community (April-June planting window) Wetland buffer area preserved to maximum extent possible Comments: F-7 New York State Stormwater Management Design Manual Appendix F Actions to be Taken: F-8 New York State Stormwater Management Design Manual Appendix F Open Channel System Construction Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: CONSTRUCTION SEQUENCE SATISFACTORY I COMMENTS UNSATISFACTORY 1. Pre-Construction Pre-construction meeting Runoff diverted Facility location staked out 2. Excavation Size and location Side slope stable Soil permeability Groundwater/bedrock Lateral slopes completely level Longitudinal slopes within design range Excavation does not compact subsoils 3. Check dams Dimensions Spacing Materials F-20 New York State Stormwater Management Design Manual Appendix F CONSTRUCTION SEQUENCE SATISFACTORY I COMMENTS UNSATISFACTORY 4. Structural Components Underdrain installed correctly Inflow installed correctly Pretreatment devices installed 5. Vegetation Complies with planting specifications Topsoil adequate in composition and placement Adequate erosion control measures in place 6. Final inspection Dimensions Check dams Proper outlet Effective stand of vegetation and stabilization Contributing watershed stabilized before flow is routed to the factility Comments: F-21 New York State Stormwater Management Design Manual Appendix F Actions to be Taken: F-22 Attachment J: NYSDEC Operation & Maintenance Checklist (Sample Form) Appendix G: Maintenance Inspection Checklists Stormwater Pond/Wetland Operation, Maintenance and Management Inspection Checklist Project Location: Site Status: Date: Time: Inspector: Maintenance Item Satisfactory/ Comments Unsatisfactory 1. Embankment and emergency spillway (Annual, After Major Storms) 1. Vegetation and ground cover adequate 2. Embankment erosion 3. Animal burrows 4. Unauthorized planting 5. Cracking, bulging, or sliding of dam a. Upstream face b. Downstream face c. At or beyond toe downstream upstream d. Emergency spillway 6.Pond, toe & chimney drains clear and functioning 7.Seeps/leaks on downstream face 8.Slope protection or riprap failure 9. Vertical/horizontal alignment of top of dam "As-Built" G-1 New York State Stormwater Management Design Manual Appendix G Maintenance Item Satisfactory/ Comments Unsatisfactory 10. Emergency spillway clear of obstructions and debris 11. Other(specify) 2. Riser and principal spillway (Annual) Type: Reinforced concrete Corrugated pipe Masonry 1. Low flow orifice obstructed 2. Low flow trash rack. a. Debris removal necessary b. Corrosion control 3. Weir trash rack maintenance a. Debris removal necessary b. corrosion control 4. Excessive sediment accumulation insider riser 5. Concrete/masonry condition riser and barrels a. cracks or displacement b. Minor spalling (<1" ) c. Major spalling (rebars exposed) d. Joint failures e. Water tightness 6. Metal pipe condition 7. Control valve a. Operational/exercised b. Chained and locked 8. Pond drain valve a. Operational/exercised b. Chained and locked 9. Outfall channels functioning 10. Other(specify) G-2 New York State Stormwater Management Design Manual Appendix G Maintenance Item Satisfactory/ Comments Unsatisfactory 3. Permanent Pool (Wet Ponds) (monthly) 1. Undesirable vegetative growth 2. Floating or floatable debris removal required 3. Visible pollution 4. Shoreline problem 5. Other(specify) 4. Sediment Forebays 1.Sedimentation noted 2. Sediment cleanout when depth < 50% design depth 5. Dry Pond Areas 1. Vegetation adequate 2. Undesirable vegetative growth 3. Undesirable woody vegetation 4. Low flow channels clear of obstructions 5. Standing water or wet spots 6. Sediment and /or trash accumulation 7. Other(specify) 6. Condition of Outfalls (Annual , After Major Storms) 1. Riprap failures 2. Slope erosion 3. Storm drain pipes 4.Endwalls/ Headwalls 5. Other(specify) 7. Other ( Monthly) 1. Encroachment on pond, wetland or easement area G-3 New York State Stormwater Management Design Manual Appendix G Maintenance Item Satisfactory/ Comments Unsatisfactory 2. Complaints from residents 3.Aesthetics a. Grass growing required b. Graffiti removal needed c. Other(specify) 4. Conditions of maintenance access routes. 5. Signs of hydrocarbon build-up 6. Any public hazards (specify) 8. Wetland Vegetation (Annual) 1. Vegetation healthy and growing Wetland maintaining 50% surface area coverage of wetland plants after the second growing season. (If unsatisfactory, reinforcement plantings needed) 2. Dominant wetland plants: Survival of desired wetland plant species Distribution according to landscaping plan? 3. Evidence of invasive species 4. Maintenance of adequate water depths for desired wetland plant species 5. Harvesting of emergent plantings needed 6. Have sediment accumulations reduced pool volume significantly or are plants "choked"with sediment 7. Eutrophication level of the wetland. 8. Other(specify) Comments: G-4 New York State Stormwater Management Design Manual Appendix G Actions to be Taken: G-5 New York State Stormwater Management Design Manual Appendix G Open Channel Operation, Maintenance, and Management Inspection Checklist Project: Location: Site Status: Date: Time: Inspector: MAINTENANCE ITEM SATISFACTORY/ COMMENTS UNSATISFACTORY 1. Debris Cleanout (Monthly) Contributing areas clean of debris 2. Check Dams or Energy Dissipators (Annual, After Major Storms) No evidence of flow going around structures No evidence of erosion at downstream toe Soil permeability Groundwater/bedrock 3. Vegetation (Monthly) Mowing done when needed Minimum mowing depth not exceeded No evidence of erosion Fertilized per specification 4. Dewatering (Monthly) Dewaters between storms G-13 New York State Stormwater Management Design Manual Appendix G MAINTENANCE ITEM SATISFACTORY/ COMMENTS UNSATISFACTORY 5. Sediment deposition (Annual) Clean of sediment 6. Outlet/Overflow Spillway (Annual) Good condition, no need for repairs No evidence of erosion Comments: Actions to be Taken: G-14 Attachment K: Stormwater Management Summary Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 1 of 11 Town of Lansing, Tompkins County INDEX Stormwater Management Summary SiteDate—General..............................................................................................................2 Runoff Reduction Volume Management Strategy...............................................................5 DPP-1 Control Sizing..........................................................................................................7 Design Point 1 Summary (DPP-1).......................................................................................7 Methodology........................................................................................................................9 ModelingResults Tabled...................................................................................................10 StageStorage Tables..........................................................................................................11 Water Quality Volume/Runoff Reduction Volume Worksheets........................Appendix 1 Hydraulic Modeling Results...............................................................................Appendix 2 Soils.....................................................................................................................Appendix 3 Precipitation........................................................................................................Appendix 4 Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 2 of 11 Town of Lansing, Tompkins County STORMWATER MANAGEMENT SUMMARY SITE DATA - GENERAL Site Notes: This summary is for the proposed construction of a ten(10)unit residential subdivision consisting of 1100-SF homes, a maintenance building, associated driveways, an access road, and landscaping on 345,618 (7.93-AC) of land in the Town of Lansing, Tompkins County,NY. The project will disturb approximately 381,516-SF (8.75-AC) of former wooded and light underbrush area, introducing roughly 43,583-SF (1.00-AC) of new impervious cover, increasing the site total by 11%. Subcatchment Evaluation: There is one pre-developed(existing)watershed subcatchment for this site totaling 950,525-SF (21.82-AC). To the north, a runoff analysis was prepared for two separate off-site drainage areas OSC-1 (14.81-AC) and OSC-3 (1.63-AC) for pre and post developed impacts on culvert design at the proposed driveway apron in the Triphammer road swale. Runoff generally moves in a northeast to southwest direction over moderate slopes of 2- 8%. Flow from these subcatchments is collected along Triphammer Road and runs south toward Design Point Existing - 1 (DPE-1) as shown on hydrologic and hydraulic worksheet ST-10. Overall, the entire watershed is mainly wooded with the exception of the upper reaches of OSC-1 and within OSC-3, which are 2-AC developed lots. Post construction site runoff has been divided into two proposed subcatchments,PSC-1 and PSC-2. A standard 2' D x 8'W diversion swale is planned along the eastern and southern edge of PSC-2 to capture 13.87-AC of runoff from the east(OSC-2). This will redirect undisturbed area flow around the developed parcel and into the Triphammer Road swale as shown on Sheet ST-11. PSC-1 and PSC-2 represent areas that will be impacted by the proposed development. Changes in landcover during construction, minor grading modifications, and the introduction of impervious hardscape surfaces can negatively affect runoff rates and volumes and introduce pollutants as compared to previously existing conditions. As such, a plan to provide water quality volume treatment and quantity attenuation in accordance with NYSDEC standards is necessary. According to State runoff reduction requirements, the use of certain practices, such as grassed filter strips, allows for an impervious cover credit in overall water quality volume calculations. Four lots within PSC-1 and four within PSC-2 will contain shallow permeable berms to promote infiltration across the grassed lawnscape from adjacent rooftops and driveways. Any runoff that percolates through these mounds will sheet flow into the proposed road swale where it will then be carried into a dry pond for quantity attenuation. Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 3 of 11 Town of Lansing, Tompkins County Treatment Flowpath: Both proposed subcatchments have been identified as areas in need of water quality treatment due to impacts from construction and added impervious surfaces. Overall, there are eight(8) grassed filter strips, one (1) dry pond, and two (2) grassed swales that have been designed to address runoff reduction volume concerns and to treat 100%o of the site water quality volume. The dry pond has been designed to reduce runoff rates to less than pre-developed conditions as required. Site Control Methods: This project follows the newer DEC design standards on runoff reduction by applying green infrastructure techniques for water quality volume treatment. Eight grassed filter strips will yield a 0.35-AC impervious cover credit to meet NYSDEC guidance standards. Site Soils: Using the USDA Web Soil Survey, five soil types have been identified within the watershed analysis of the existing site. Conesus (CfA and CfB), Kendaia (KfB), and Lansing (LbB) are gravelly silt loams with moderately low to moderately high drainage characteristics from 0.01 — 1.42 in/hr in the hydrologic soil group B. The areas within the proposed development consist of Ovid (OaA), and Ilion (IcA) silt clay loams, with moderately low to moderately high drainage characteristics from 0.01 — 0.20 in/hr in the hydrologic soil group C. Soils data was obtained from the on-line USDA Soil Conservation Service Web Soil Survey. Site Topography: The site as a whole has a varied slope of between 2 — 8% primarily moving downhill from northeast to southwest. Site Watershed: Of the 36.63-acre watershed, the area of disturbance will be approximately 4.6-acres. Rainfall: Rainfall data used in the modeling and analysis was taken from www.precipt.net, from the Northeast Regional Climate Center which is an accepted NYSDEC reference (Appendix 4). Rainfall data specific to Tompkins County under consideration, for various 24-hour storm events tabled below: RAINFALL DATA STORM 24-HOUR RAINFALL 1-year 1.99 inches 10-year 3.40 inches 25-year 4.22 inches 100-year 5.84 inches Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 4 of 11 Town of Lansing, Tompkins County These values were used in modeling for the evaluation of existing and proposed stormwater run-off conditions. Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 5 of 11 Town of Lansing, Tompkins County RUNOFF REDUCTION VOLUME MANAGEMENT STRATEGY (See Appendix 1 for Worksheet Analyses) 1. Water Ouality Volume and Runoff Reduction Stormwater Management Strategy -Reference modeling results and WQvIPRv worksheets which follow this summary: The total site water quality volume is: WQv=4,695 cu-ft (0.108af) Of this amount, seven grassed filter strips have been proposed to provide an impervious cover credit of 0.35-AC which reduces the overall water quality volume: WQv credit= 1,729 cuft(0.040 afi Adjusted WQv =2,966 cuft(0.068 af) The minimum RRv was based on the following calculation: Soil group for site: C-7.71-ACS = 30%o Minimum RRv: S = 0.30 Impervious Area= 0.96-AC Precipitation= 1.0 in Rv=0.95 Minimum Rv= [(P)(Rv)(A)] /12= ((1.0 * 0.95"/AC *0.96AC)/12)0.30= 988 cuft or, 0.024-acft 2. Water Quality Volume Treatment Practices Seven grassed filter strips have been designed to the minimum total volume specifications as calculated in the attached practice worksheets. A summary of total runoff reduction volumes is provided in the table below: Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 6 of 1 I Town of Lansing, Tompkins County Subcatchment Required RRv (cult) RRv Adjust. (Cult) Adjusted RRv PSC-1&PSC-2 4,695 1,729 GF (Credit) 4,695 1,729 3. Total of RRv Total RRv provided by practices 1,729 cuft(0.040-AF) Total Remaining Storage Volume for practices (after RRv) 2,966 cuft - 0 cuft = 2,966cuft(0.068af) Is provided RRv>adjusted WQv from#1? 0.040 acft> 0.068 acft NO Is provided RRv>minimum RRv for C soils from#1? 0.040 acft>0.024 acft YES Is volume available within standard practices for remaining untreated WQv? YES Total Site WQv- 2,966 CF, 0.068AF RRv 0-CF, 0.000-AF Remaining WQv -2,966 CF, 0.068-AF Remaining WQv is treated by the two standard practice dry pond forebays. Each forebay offers 4,000-CF of storage which represents 8,000-CF of available WQv storage volume. Is all of the watershed drainage area treated by either area reduction or source control practices? YES Is all of the watershed impervious area treated with either reduction or source control practices? YES Minimum runoff reduction requirements are met for this project. Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 7 of 11 Town of Lansing, Tompkins County DPP-1 CONTROL SIZING Dry Pond Cpv=24 hour extended detention of post-developed 1-year, 24-hour Storm event(1.99-inch rainfall Tompkins County) - 1 yr Cpv 0.267-AF (11,631-CF)— RRv credit of 0.040AF (1,729-CF) =(9,902-CF). Pond CPv orifice 1. Determine H—Avg head above centerline of proposed orifice invert for 1 yr storm. H between 962.00 and 964.72 (1 Yr Peak)=2.72/2 = 1.36' 2. Determine Q—Flow over 24 hr period. 1 Yr Peak Volume= Stage storage table volume between 964.72 and 0.00' _ 8,362 cuft 8,362 cuft/day x ld/24hrs x lhr/60min x 1 min/60sec= 0.0968cfs 3. A= Q/ [Cs * Sgrt(2gH)] Where, Cs=0.6 and g=32.2 ft/s2 A= 0.0968 cfs/ [0.6(Sgrt(2*32.2 ft/s2*1.36 ft)] =0.0172 ft2 4. A=zzr2 r2= Sgrt(0.0172 ft2/3.14) * 2=0.148 ft or 1.68, round up to 2.0" Orifice can adequately outlet the 1 yr 24 hour storm —Entire storm captured. CPv conditions are met. DESIGN POINT 1 SUMMARY (DP-1) Overbank Flood (00—DP1 Qp= Controls the peak discharge from the 10-year storm (3.40-inch rainfall Tompkins County) to 10-year predevelopment rates. Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 8 of 11 Town of Lansing, Tompkins County Pre-developed max rate= 14.48-CFS, Total Volume=2.297AF (100,057-CF). Post- developed w/o controls max rate= 15.45-CFS, Total Volume=2.574-AF (112,123-CF). The maximum post-developed run-off rate with the dry pond in-line is 10.92-CFS, and the total run-off volume is 2.048-AF (89,211-CF). The Qp Overbank Flood control criterion is met with the dry pond in-line. Extreme Storm (Of)—DPI Control the peak discharge from the 100-year storm (5.84-inch rainfall Tompldns County) to 100-year predevelopment rates. Safely pass the 100-year storm event. Pre-developed max run-off rate=50.17-CFS, Total Volume= 7.062-AF (307,621-CF). Post-developed w/o controls max rate=48.54-CFS, Total Volume =7.513-AF (327,266- CF). The maximum post-developed run-off rate with the dry pond inline is 45.91-CFS, and the total run-off volume is 6.935-AF (278,566-CF). The Qf Overbank Flood control criterion is met with the dry pond in-line. Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 9 of 11 Town of Lansing, Tompkins County METHODOLOGY The methodology used for the hydrologic and hydraulic analysis was obtained from the United States Department of Agriculture (USDA) Soil Conservation Service's (SCS) Technical Release No. 20, as implemented by the application program HydroCAD. HydroCAD, developed by Applied Microcomputer Systems of Chocorua,New Hampshire, is a Computer-Aided-Design (CAD)program for analyzing the hydrologic and hydraulic characteristics of a given watershed and associated stormwater management facilities. It utilizes the latest modeling techniques to predict the consequences of any given storm. HydroCAD has the capability of computing hydrographs and routing flows through pipes, streams and ponds. Hydrographs represent discharge rates characteristic of specified watershed conditions,precipitation and geologic factors. For this analysis, the watershed and drainage system was broken down into a network consisting of three types of components described below: Subcatchment: A relatively homogeneous area of land,which produces a volume and rate of surface run-off unique to that area. Reach: Uniform streams, channels or pipes which convey stormwater from one distinct point to another reach or pond. Pond: Natural or man-made impoundment (ie. pond), which temporarily stores stormwater run-off and empties in a manner determined by its geometry and the hydraulic structure located at its outlet(s). Subcatchments, reaches and ponds are represented by hexagons, squares and triangles, respectively, on the watershed routing diagrams provided with the computations reference modeling results attached. Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 10 of 11 Town of Lansing, Tompkins County MODELING RESULTS TABLED (See Appendix 2 for actual modeling data) DPP-1 EXISTING EXISTING FLOW CONDITIONS AT DESIGN POINT DPI STORMEVENT PEAKFLOW TOTAL VOLUME CFS AF ]-year 1.90 0.478 10- ear 14.48 2.297 100- ear 50.17 7.062 PROPOSED WITHOUT STORMWA TER MANAGEMENT FLOW CONDITIONS AT DESIGN POINT DPI STORMEVENT PEAKFLOW TOTAL VOLUME CFS AF 1-year 3.04 0.618 10- ear 15.45 2.574 100- ear 1 48.54 1 7.513 PROPOSED WITH DRY POND IN-LINE PROPOSED FLOW CONDITIONS AT DESIGN POINT(DPI) STORMEVENT PEAKFLOW TOTAL VOLUME (CFS AF 1-ye 1.42 0.431 10- ear 10.92 2.048 100- ear 45.91 6.935 Stormwater Management Summary August 2020,REV December 2020 Proposed Britton Single Family Homes Page 11 of 11 Town of Lansing, Tompkins County STAGE STORAGE TABLES DRYPOND STAGE-STORAGE TABLE P STORMEVENT PEAK PEAKDEPTH STORAGE CF FT WQv 2,966 0.85' 1 year (Cpv) 6,594 1.48' 10 year 21.567 3.06' 100 year 1 34,217 1 4.05' Notes: Invert of Dry Pond=El. 0' Invert I Yr Primary Outlet(2.0"dia orifice Culvert)El. = 0.0' Invert 10 Yr Primary Outlet(12.0"dia. Culvert)El. =2.72' Invert Qf Outlet(18"horizontal outlet)El. = 3.00' Invert of Emergenyc Overflow— 10'x 4'broadcrested weir = 3.75' Top of Pond Crest Elev. El. = 5.00' APPENDIX 1 WATER QUALITY VOLUME/RUNOFF REDUCTION WORKSHEETS Version 1.6 Total Water Quality Volume Calculation Last Updated: 03/28/2014 WQv(acre-feet) = [(P)(Rv)(A)] /12 Is this project subject to Chapter 10 of the NYS Design Manual (i.e. WQv is equal to post- development 1 year runoff volume)?...................................................................................... No Design Point: 1 Manually enter P, Total Area and Impervious Cover. P=J 1.00 1 inch Breakdown of Subcatchments Catchment Total Area Impervious Area Percent WQv Impervious Rv 3 Description Number (Acres) (Acres) (ft ) 1 0.32 0.05 16% 0.19 221 Filter Strips-PSC 1a 2 0.68 0.05 7% 0.12 287 Filter Strips-PSC 1b 3 0.59 0.05 8% 0.13 270 Filter Strips-PSC 1c 4 0.62 0.05 7% 0.12 260 Filter strips-PSC 1d 5 6 7 8 9 10 Subtotal (1-30) 2.21 0.20 9% 0.13 1,038 Subtotal 1 Total 2.21 0.20 9% 0.13 1,038 Initial WQv Identify Runoff Reduction Techniques By Area Total Contributing Technique Contributing Impervious Area Notes Area (Acre) (Acre) Conservation of Natural Areas 0.00 0.00 minimum 10,000 sf Riparian Buffers 0.00 0.00 maximum contributing length 75 feet to 150 feet Filter Strips 2.21 0.20 Tree Planting 0.00 0.00 Up to 100 sf directly connected impervious area may be subtracted per tree Total 2.21 0.20 Recalculate WQv after application of Area Reduction Techniques Total Area Impervious Area Percent Runoff WQv Impervious Coefficient 3 (Acres) (Acres) "" Rv (ft ) "«Initial WQv" 2.21 0.20 9% 0.13 1,038 Subtract Area -2.21 -0.20 WQv adjusted after Area 0.00 0.00 0% 0.05 0 Reductions Disconnection of Rooftops 0.00 wim t- J Version 1.6 Total Water Quality Volume Calculation Last Updated: 03/28/2014 WQv(acre-feet) = [(P)(Rv)(A)] /12 Adjusted WQv after Area Reduction and Rooftop 0.00 0.00 0% 0.05 0 Disconnect T WQv reduced by Area 1,03 Reduction techniques Total Water Quality Volume Calculation WQv(acre-feet) = [(P)(Rv)(A)] /12 All Subcatchments Catchment Total Area Impervious Percent Runoff WQv Description Cover Impervious Coefficient (Acres) (Acres) % Rv (ft 3) 1 0.32 0.05 0.16 0.19 221.43 Filter Strips- PSC 1a 2 0.68 0.05 0.07 0.12 287 Filter Strips- PSC 1b 3 0.59 0.05 0.08 0.13 270.44 Filter Strips- 4 0.62 0.05 0.07 0.12 259.55 Filter Strips- PSC 1d 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Total Runoff Reduction Tech iques/Standard Total Contributing Contributing WQv Reduced WQv SMps Area Impervious (RRv) Treated Area T (acres) (acres) cf cf Conservation of Natural Areas RR-1 0.00 0.00 Sheetflow to Riparian Buffers/Filter RR-2 2.21 0.20 .0o Strips Tree Planting/Tree Pit RR-3 0.00 0.00 Disconnection of Rooftop Runoff RR-4 0.00 Vegetated Swale RR-5 0.00 0.00 0 o Rain Garden RR-6 0.00 0.00 0 Stormwater Planter RR-7 0.00 0.00 0 Rain Barrel/Cistern RR-8 0.00 0.00 0 a Porous Pavement RR-9 0.00 0.00 0 Green Roof(Intensive & Extensive) RR-10 0.00 0.00 0 Infiltration Trench 1-1 0.00 0.00 0 0 a Infiltration Basin 1-2 0.00 0.00 0 0 U � Q Dry Well 1-3 0.00 0.00 0 0 U Underground Infiltration System 1-4 0.00 N3 Bioretention & Infiltration Bioretention F-5 0.00 0.00 0 0 Dry swale 0-1 0.00 0.00 0 0 Micropool Extended Detention (P-1) P-1 Wet Pond (P-2) P-2 Wet Extended Detention (P-3) P-3 Multiple Pond system (P-4) P-4 Pocket Pond (p-5) P-5 Surface Sand filter(F-1) F-1 _0 Underground Sand filter(F-2) F-2 L a Perimeter Sand Filter(F-3) F-3 fu Organic Filter(F-4 F-4 `n Shallow Wetland (W-1) W-1 Extended Detention Wetland (W-2 W-2 Pond/Wetland System (W-3) W-3 Pocket Wetland (W-4) W-4 Wet Swale (0-2) 0-2 Totals by Area Reduction 2.21 0.20 1038 Totals by Volume Reduction 0.00 0.00 0 Totals by Standard SMP w/RRV 0.00 0.00 0 0 Totals by Standard SMP 0.00 0.00 0 Totals ( Area + Volume + all SMPs) -> 2.21 0.20 1,038 0 Impervious Cover V I okay Minimum RRv Enter the Soils Data for the site Soil Group Acres S A 55% B 40% C 2.32 30% D 20% Total Area 2.32 Calculate the Minimum RRv S= 0.30 Impervious= 0.20 acre Precipitation 1 in Rv 0.95 Minimum RRv 202 ft3 0.00 of Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 1 0.32 0.05 0.16 0.19 221.43 1.00 Filter Strips - PSC 1a Design Elements Is another area based practice applied to No YIN this area? Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from heavy equipment during construction? Yes YIN Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope<3.0% level spreader shall be used for buffer slopes ranging from 3-15% Average contributing slope 2% % 3%maximum unless a level spreader is Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 84 ft 150 ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum (IC) Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% Filter Strip Width 70 ft 75 ft minimum for slopes 8-12% 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria for Filter Strips in Section Yes 5.3.2 met? Area Reduction Adjustments Subtract 0.32 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 2 0.68 0.05 0.07 0.12 286.77 1.00 Filter Strips - PSC 1b Design Elements Is another area based practice applied to No YIN this area? Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from Yes YIN heavy equipment during construction? Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope<3.0% level spreader shall be used for buffer slopes ranging from 3-15% Average contributing slope 2 3%maximum unless a level spreader is used. Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 49 ft 150 ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% Filter Strip Width 70 ft 75 ft minimum for slopes 8-12% 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria for filter strips in Section Yes 5.3.2 met? Area Reduction Adjustments Subtract 0.68 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 3 0.59 0.05 0.08 0.13 270.44 1.00 Filter Strips - PSC 1c Design Elements Is another area based practice applied to this area? No YIN Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from Yes YIN heavy equipment during construction? Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope<3.0% level spreader shall be used for buffer slopes ranging from 3-15% Average contributing slope 2 3%maximum unless a level spreader is Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 54 ft 150 ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% 75 ft minimum for slopes 8-12% Filter Strip Width 70 ft 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria in Section 5.3.2(filter Yes strips) met? Area Reduction Adjustments Subtract 0.59 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 4 0.62 0.05 0.07 0.12 259.55 1.00 Filter Strips - PSC 1d Design Elements Is another area based practice applied to this area? No YIN Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from heavy equipment during construction? Yes YIN Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Permeable Berm at bottom Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope <3.0% level spreader shall be used for buffer slopes rongingfrom 3-15% Average contributing slope 2 % 3%maximum unless a level spreader is used. Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 42 ft 1150ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum (IC) Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% Filter Strip Width 70 ft 75 ft minimum for slopes 8-12% 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria in Section 5.3.2(fitler Yes strips) met? Area Reduction Adjustments Subtract 0.62 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE Filter Strip Total Subtracted from Total Area 2.21 Total Subtracted from Total Impervious Area0.20 Version 1.6 Total Water Quality Volume Calculation Last Updated: 03/28/2014 WQv(acre-feet) = [(P)(Rv)(A)] /12 Is this project subject to Chapter 10 of the NYS Design Manual (i.e. WQv is equal to post- development 1 year runoff volume)?...................................................................................... No Design Point: 1 Manually enter P, Total Area and Impervious Cover. P=J 1.00 1 inch Breakdown of Subcatchments Catchment Total Area Impervious Area Percent WQv Impervious Rv 3 Description Number (Acres) (Acres) (ft ) 1 0.43 0.05 12% 0.15 241 Filter Strips-PSC 2e 2 0.24 0.05 21% 0.24 207 Filter Strips-PSC 2f 3 0.36 0.05 14% 0.18 229 Filter Strips-PSC 2g 4 4.72 0.65 14% 0.17 2,980 Dry Pond 5 6 7 8 9 10 Subtotal (1-30) 5.75 0.80 14% 0.18 3,657 Subtotal 1 Total 5.75 0.80 14% 0.18 3,657 Initial WQv Identify Runoff Reduction Techniques By Area Total Contributing Technique Contributing Impervious Area Notes Area (Acre) (Acre) Conservation of Natural Areas 0.00 0.00 minimum 10,000 sf Riparian Buffers 0.00 0.00 maximum contributing length 75 feet to 150 feet Filter Strips 1.03 0.15 Up to 100 sf directly connected impervious Tree Planting 0.00 0.00 area may be subtracted per tree Total 1.03 0.15 Recalculate WQv after application of Area Reduction Techniques Total Area Impervious Area Percent Runoff WQv (Acres) (Acres) Impervious Coefficient (ft 3 ) % Rv "<<Initial WQv" 5.75 0.80 14% 0.18 3,657 Subtract Area -1.03 -0.15 WQv adjusted after Area 4.72 0.65 14% 0.17 2,980 Reductions Disconnection of Rooftops 1 0.00 Version 1.6 Total Water Quality Volume Calculation Last Updated: 03/28/2014 WQv(acre-feet) = [(P)(Rv)(A)] /12 Adjusted WQv after Area Reduction and Rooftop 4.72 0.65 14% 0.17 2,980 Disconnect WQv reduced by Area Reduction techniques T 677 Total Water Quality Volume Calculation WQv(acre-feet) = [(P)(Rv)(A)] /12 All Subcatchments Catchment Total Area Impervious Percent Runoff WQv Description Cover Impervious Coefficient (Acres) (Acres) % Rv (ft 3) 1 0.43 0.05 0.12 0.15 241.40 Filter Strips- PSC 2e 2 0.24 0.05 0.21 0.24 207 Filter Strips- PSC 2f 3 0.36 0.05 0.14 0.18 228.69 Filter Strips- 4 4.72 0.65 0.14 0.17 2980.23 Dry Pond 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Total Runoff Reduction Tech iques/Standard Total Contributing Contributing WQv Reduced WQv SMps Area Impervious (RRv) Treated Area T (acres) (acres) cf cf Conservation of Natural Areas RR-1 0.00 0.00 Sheetflow to Riparian Buffers/Filter RR-2 1.03 0.15 .0o Strips Tree Planting/Tree Pit RR-3 0.00 0.00 Disconnection of Rooftop Runoff RR-4 0.00 Vegetated Swale RR-5 0.00 0.00 0 o Rain Garden RR-6 0.00 0.00 0 Stormwater Planter RR-7 0.00 0.00 0 Rain Barrel/Cistern RR-8 0.00 0.00 0 a Porous Pavement RR-9 0.00 0.00 0 Green Roof(Intensive & Extensive) RR-10 0.00 0.00 0 Infiltration Trench 1-1 0.00 0.00 0 0 a Infiltration Basin 1-2 0.00 0.00 0 0 U � Q Dry Well 1-3 0.00 0.00 0 0 U Underground Infiltration System 1-4 0.00 N3 Bioretention & Infiltration Bioretention F-5 0.00 0.00 0 0 Dry swale 0-1 0.00 0.00 0 0 Micropool Extended Detention (P-1) P-1 Wet Pond (P-2) P-2 Wet Extended Detention (P-3) P-3 Multiple Pond system (P-4) P-4 Pocket Pond (p-5) P-5 4.72 0.65 2777.000 Surface Sand filter(F-1) F-1 _0 Underground Sand filter(F-2) F-2 L a Perimeter Sand Filter(F-3) F-3 fu Organic Filter(F-4 F-4 `n Shallow Wetland (W-1) W-1 Extended Detention Wetland (W-2 W-2 Pond/Wetland System (W-3) W-3 Pocket Wetland (W-4) W-4 Wet Swale (0-2) 0-2 Totals by Area Reduction 1.03 0.15 677 Totals by Volume Reduction 0.00 0.00 0 Totals by Standard SMP w/RRV 0.00 0.00 0 0 Totals by Standard SMP 4.72 0.65 2777 Totals ( Area + Volume + all SMPs) -> 5.75 0.80 677 2,777 Impervious Cover V I okay Minimum RRv Enter the Soils Data for the site Soil Group Acres S A 55% B 40% C 5.39 30% D 20% Total Area 5.39 Calculate the Minimum RRv S= 0.30 Impervious= 0.80 acre Precipitation 1 in Rv 0.95 Minimum RRv 828 ft3 0.02 laf Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 1 0.43 0.05 0.12 0.15 241.40 1.00 Filter Strips - PSC 2e Design Elements Is another area based practice applied to this area? No YIN Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from yes YIN heavy equipment during construction? Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope<3.0% level spreader shall be used for buffer slopes ranging from 3-15% Average contributing slope 2 % 3%maximum unless a level spreader is Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 70 ft 150 ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum (IC) Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% Filter Strip Width 70 ft 75 ft minimum for slopes 8-12% 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria for Filter Strips in Section Yes 5.3.2 met? Area Reduction Adjustments Subtract 0.43 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 2 0.24 0.05 0.21 0.24 206.91 1.00 Filter Strips - PSC 2f Design Elements Is another area based practice applied to No YIN this area? Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from Yes YIN heavy equipment during construction? Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope<3.0% level spreader shall be used for buffer slopes ranging from 3-15% Average contributing slope 2 3%maximum unless a level spreader is used. Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 90 ft 150 ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% Filter Strip Width 70 ft 75 ft minimum for slopes 8-12% 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria for filter strips in Section Yes 5.3.2 met? Area Reduction Adjustments Subtract 0.24 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE Filter Strip Design Point:1 1 Enter Site Data For Drainage Area to be Treated by Practice Catchment Total Area Impervious Percent WQv Precipitation Area Impervious Rv 3 Description Number (Acres) (Acres) % (ft ) (in) 3 0.36 0.05 0.14 0.18 228.69 1.00 Filter Strips - PSC 2g Design Elements Is another area based practice applied to No YIN this area? Amended Soils& Dense Turf Cover? Yes YIN Is area protected from compaction from Yes YIN heavy equipment during construction? Small Area of Impervious Area &close to Yes YIN source? Composte Amendments? Yes YIN Boundary Spreader? Yes YIN Gravel Diaphram at top Boundary Zone? Yes YIN 25 feet of level grass Specify how sheet flow will be ensured. Slope<3% level spreader shall be used for buffer slopes ranging from 3-15% Average contributing slope 2 3%maximum unless a level spreader is Slope of first 10 feet of Filter Strip 2 % 2%maximum Overall Slope 2 % 8%maximum Contributing Length of Pervious Areas (PC) 90 ft 150 ft maximum Contributing Length of Impervious areas 58 ft 75 ft maximum IC Maximum PC Contributing Length for combination of PC& IC 92 ft Soil Group (HSG) C 50 ft minimum for slopes 0-8% Filter Strip Width 70 ft 75 ft minimum for slopes 8-12% 100 ft minimum for slopes 12-15% HSG C or D increase by 15-20% Are All Criteria in Section 5.3.2(filter Yes strips) met? Area Reduction Adjustments Subtract 0.36 Acres from total Area Subtract 0.05 Acres from total Impervious Area TRUE APPENDIX 2 HYDRAULIC MODELING DATA EOS1 EE7S Off-Site ubcatchment 1 Off-Site Subcatch ant 3 Q9G3 OSC 1 Off-Site Sub chment 3 Off-Sit Subcatchment 1 DPE �- ESC Design Point Existing Subcatchment zvcwwn Summation-Existing PSC-1 24"Culvert Proposed Subcatchmen 1 DPP 1az Design Poin Dry Pond 1 and 2 Summation-Prop ad PSC-2 Proposed Subcatchment 2 OSG2° Off-Site Subcatchment 2 SubCat Reach on Link Routing Diagram for Britton_Model Prepared by{enter your company name here}, Printed 8/17/2020 HydroCAD®10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Britton-1 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 13.361 65 2 acre lots, 12% imp, HSG B (EOS1, OSC 1) 5.856 77 2 acre lots, 12% imp, HSG C (EOS1, EOS3, OSC 1, OSC-3) 6.934 74 >75% Grass cover, Good, HSG C (PSC-1, PSC-2) 1.001 98 Paved parking, rooftops, road, HSG C (PSC-1, PSC-2) 17.255 58 Woods/grass comb., Good, HSG B (EOS1, ESC, OSC 1, OSC-2) 32.104 72 Woods/grass comb., Good, HSG C (EOS1, EOS3, ESC, OSC 1, OSC-2, OSC-3) 76.510 69 TOTAL AREA Britton-1 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 3 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 13.361 5.856 0.000 0.000 19.216 2 acre lots, 12% imp EOS1 EOS3 OSC 1, OSC- 3 0.000 0.000 6.934 0.000 0.000 6.934 >75% Grass cover, Good PSC- 1, PSC- 2 0.000 0.000 1.001 0.000 0.000 1.001 Paved parking, rooftops, road PSC- 1, PSC- 2 0.000 17.255 32.104 0.000 0.000 49.359 Woods/grass comb., Good EOS1 EOS3 ESC, OSC 1, OSC- 2, OSC- 3 0.000 30.616 45.894 0.000 0.000 76.510 TOTAL AREA Britton-1 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 4 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 24" Culvert 961.50 961.30 64.0 0.0031 0.013 24.0 0.0 0.0 2 P 1&2 962.00 961.70 53.0 0.0057 0.013 15.0 0.0 0.0 Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 5 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEOS1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>0.15" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=0.74 cfs 0.188 of SubcatchmentEOS3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>0.32" Flow Length=606' Tc=32.5 min CN=75 Runoff=0.38 cfs 0.044 of SubcatchmentESC: Existing Runoff Area=950,525 sf 0.00% Impervious Runoff Depth>0.14" Flow Length=1,606' Tc=50.9 min CN=67 Runoff=1.02 cfs 0.247 of SubcatchmentOSC 1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>0.15" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=0.74 cfs 0.188 of SubcatchmentOSC-2: Off-Site Runoff Area=604,235 sf 0.00% Impervious Runoff Depth>0.10" Flow Length=2,344' Tc=41.3 min CN=65 Runoff=0.44 cfs 0.120 of SubcatchmentOSC-3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>0.32" Flow Length=606' Tc=32.5 min CN=75 Runoff=0.38 cfs 0.044 of SubcatchmentPSC-1: Proposed Runoff Area=147,569 sf 15.15% Impervious Runoff Depth>0.42" Flow Length=1,041' Tc=12.4 min CN=78 Runoff=2.07 cfs 0.120 of SubcatchmentPSC-2: Proposed Runoff Area=198,047 sf 10.72% Impervious Runoff Depth>0.39" Flow Length=979' Tc=28.8 min CN=77 Runoff=1.48 cfs 0.147 of Reach 24" Culvert:24" Culvert Avg. Flow Depth=0.36' Max Vet=2.32 fps Inflow=0.89 cfs 0.232 of 24.0" Round Pipe n=0.013 L=64.0' S=0.0031 T Capacity=12.65 cfs Outflow=0.89 cfs 0.232 of Reach DPE: Design Point Summation- Existing Inflow=1.90 cfs 0.478 of Outflow=1.90 cfs 0.478 of Reach DPP: Design Point Summation- Proposed Inflow=1.42 cfs 0.431 of Outflow=1.42 cfs 0.431 of Pond P 1&2: Dry Pond 1 and 2 Peak Elev=963.48' Storage=6,594 cf Inflow=2.81 cfs 0.266 of Discarded=0.08 cfs 0.053 of Primary=0.12 cfs 0.080 of Outflow=0.21 cfs 0.132 of Total Runoff Area = 76.510 ac Runoff Volume = 1.096 of Average Runoff Depth = 0.17" 95.68% Pervious = 73.203 ac 4.32% Impervious = 3.307 ac Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment EOS1: Off-Site Subcatchment 1 Runoff = 0.74 cfs @ 12.93 hrs, Volume= 0.188 af, Depth> 0.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment EOS1: Off-Site Subcatchment 1 Hydrograph 0.8 0.74 cfs —Runoff 0.75 0.7 Type 11 24-hr 006.65 Rainfall=1 .99" 0.55 Runoff Area=645,339 sf 05 Runoff Volume=0.188 of 0.45 0 0.4 Runoff Depth>0.15" LL 0.35 Flow Length=2,082' 0.3- 0.25 Tc=63.8 m i n 0.2 CN=68 0.15 0.1 ------------------ 0.05 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment EOS3: Off-Site Subcatchment 3 Runoff = 0.38 cfs @ 12.33 hrs, Volume= 0.044 af, Depth> 0.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment EOS3: Off-Site Subcatchment 3 Hydrograph 0.42 ----- 0.4 0.38 cfs -Runoff 0.38 0.36 Type II 24-hr 0.34 0.32 Rainfall=1 .99" 0.3 °.28 Runoff Area=70,850 sf 0.26 -------------- ---------- - - Z. 0.24 ', ', Runoff Volume=0.044 of o °0 2 _ Runoff Depth>0.32" LL 0.16_ Flow Length=606' 0.14 0.12 Tc=32.5 m i n 0.1 ---------- - -I --------- --- CN=75 0.08 0.06 0.04 - - - - - - - - - - - - -- - - - - - - - - - - 0.02 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment ESC: Existing Subcatchment Runoff = 1.02 cfs @ 12.75 hrs, Volume= 0.247 af, Depth> 0.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 334,278 58 Woods/grass comb., Good, HSG B 616,247 72 Woods/grass comb., Good, HSG C 950,525 67 Weighted Average 950,525 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.6 150 0.0700 0.13 Sheet Flow, First 150' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 31.3 1,456 0.0240 0.77 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 50.9 1,606 Total Subcatchment ESC: Existing Subcatchment Hydrograph 1.02 cfs —Runoff Type 11 24-h r Rainfall=1 .99" Runoff Area=950,525 sf Runoff Volume=0.247 of Runoff Depth>0.14" LL i Flow Length=1 ,606' Tc=50.9 m i n CN=67 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment OSC 1: Off-Site Subcatchment 1 Runoff = 0.74 cfs @ 12.93 hrs, Volume= 0.188 af, Depth> 0.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment OSC 1: Off-Site Subcatchment 1 Hydrograph 0.8 0.74 cfs —Runoff 0.75 ----- 0.7 Type 11 24-hr 006.65 Rainfall=1 .99" 0.55 Runoff Area=645,339 sf 05 Runoff Volume=0.188 of 0.45 0 0.4 Runoff Depth>0.15" LL 0.35 Flow Length=2,082' 0.3- 0.25 Tc=63.8 m i n 0.2 CN=68 0.15 0.1 ----------------- 0.05 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 1124-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment OSC-2: Off-Site Subcatchment 2 Runoff = 0.44 cfs @ 12.66 hrs, Volume= 0.120 af, Depth> 0.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 287,733 58 Woods/grass comb., Good, HSG B 316,502 72 Woods/grass comb., Good, HSG C 604,235 65 Weighted Average 604,235 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.2 100 0.0700 0.12 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 24.2 1,102 0.0230 0.76 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 2.9 1,142 0.0180 6.51 65.06 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 & 0.0 7' Top.W=8.00' n= 0.030 41.3 2,344 Total Subcatchment OSC-2: Off-Site Subcatchment 2 Hydrograph 0.48 0.46 0.44 cfs -Runoff 0.44 0 .4 0Type 11 24-hr .4 0.36 Rainfall=1 .99" 0.32 Runoff Area=604,235 sf 0.3 Runoff Volume=0.120 of H 0.28 0.2s 3 0.24 -Runoff Depth>0.10" a: 0.22 0.2 Flow Length=2,344' 0.18 0.16 --Tc=41 .3-min - --,-------- --- ------- -0.14 0.1 . CN=65 0.08 0.06 0.04 0.02- 0 . . . . . . . 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 11 Summary for Subcatchment OSC-3: Off-Site Subcatchment 3 Runoff = 0.38 cfs @ 12.33 hrs, Volume= 0.044 af, Depth> 0.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment OSC-3: Off-Site Subcatchment 3 Hydrograph 0.42 --- - -____ - 0.4 0.38 cfs -Runoff 0.38 0.36 Type II 24-hr 0.34 0.32 Rainfall=1 .99" 0.3 °.28 Runoff Area=70,850 sf 0.26 -------------- ---------- - - Z. 0.24 ', ', Runoff Volume=0.044 of °02 o - Runoff Depth>0.32" LL 0.16_ Flow Length=606' 0.14 0.12 Tc=32.5 m i n 0.1 ---------- --------- --- CN=75 0.08 0.06 0.04 - - - - - - - - - - - - -- - - - - - - - - - - 0.02 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 12 Summary for Subcatchment PSC-1: Proposed Subcatchment 1 Runoff = 2.07 cfs @ 12.06 hrs, Volume= 0.120 af, Depth> 0.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 22,354 98 Paved parking, rooftops, road, HSG C 125,215 74 >75% Grass cover, Good, HSG C 147,569 78 Weighted Average 125,215 84.85% Pervious Area 22,354 15.15% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.0500 0.15 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 0.5 43 0.0480 1.53 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 0.2 25 0.0150 2.49 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 0.9 873 0.0180 16.26 260.24 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 7' Top.W=14.00' n= 0.013 12.4 1,041 Total Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 13 Subcatchment PSC-1: Proposed Subcatchment 1 Hydrograph 2.07 cfs e Runoff 2 Type 11 24-hr Rai nfall=1 .9'9" Runoff Area=147,569 sf y Runoff Volume=0.120'af v Runoff Depth>0.42" LL 1 Flow Length=1 ,041' Tc=12.4 min CN=78 o- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment PSC-2: Proposed Subcatchment 2 Runoff = 1.48 cfs @ 12.27 hrs, Volume= 0.147 af, Depth> 0.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=1.99" Area (sf) CN Description 21,230 98 Paved parking, rooftops, road, HSG C 176,817 74 >75% Grass cover, Good, HSG C 198,047 77 Weighted Average 176,817 89.28% Pervious Area 21,230 10.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.2 100 0.0300 0.13 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 15.6 879 0.0180 0.94 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 28.8 979 Total Subcatchment PSC-2: Proposed Subcatchment 2 Hydrograph 1.48 cfs —Runoff Type 11 24-hr Rainfall=1 .99" Runoff Area=198,047 sf w Runoff'Volume=0.147 of Runoff Depth>0.39" LL Flow Length=979' Tc=28.8 m i n CN=77 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 15 Summary for Reach 24" Culvert: 24" Culvert [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 16.441 ac, 7.01% Impervious, Inflow Depth > 0.17" Inflow = 0.89 cfs @ 12.84 hrs, Volume= 0.232 of Outflow = 0.89 cfs @ 12.86 hrs, Volume= 0.232 af, Atten= 0%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 2.32 fps, Min. Travel Time= 0.5 min Avg. Velocity = 1.67 fps, Avg. Travel Time= 0.6 min Peak Storage= 25 cf @ 12.85 hrs Average Depth at Peak Storage= 0.36' Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 12.65 cfs 24.0" Round Pipe n= 0.013 Length= 64.0' Slope= 0.0031 T Inlet Invert= 961.50', Outlet Invert= 961.30' Britton_1 Yr Rain Event Britton Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 16 Reach 24" Culvert: 24" Culvert Hydrograph 0099 , - -- 0.89 cfs -- — l Infow ---- ---'- --- —Outflow 0.85 --Inflow Area=16.441 ac ---- - --- - - - - - - - - 0.8 -- - -------- --------T--------,- 0.75 -Avg. Flout Depth=0.36' r- --- -------r--------r-------------- 0.65 --M x Vel=�.32 fps ----r- --�-- -- ----r----�----r----�----,---- w0.55 ---+- ---+---+--- ---+-- +----+---+----+----i--------- Round P" LL o45 n��.�1 - t--- --- -- - ----- ---+------------- I---- ---- 0.4 -- --------- ---------- 0.35 L=64.0' 0.3 ---+- --------+----+--------- ----+---+----+ ------+----i---- ---- S#0.0031-T ---- -- --- 0.2 -C#--acit-=�42:65-cfs -- 0.15 --- ---- ----- ----' -------- - -------- --------_---- 0.05 --- - --------------' -------_ ----------- 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_1 Yr Rain Event Britton Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 17 Summary for Reach DPE: Design Point Summation - Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.262 ac, 3.01% Impervious, Inflow Depth > 0.15" Inflow = 1.90 cfs @ 12.78 hrs, Volume= 0.478 of Outflow = 1.90 cfs @ 12.78 hrs, Volume= 0.478 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPE: Design Point Summation - Existing Hydrograph 2 1.90 cfs - - - - Inflow —Outflow Inflow Area=38.262 ac I I I I I I I I I I N I I i I I I I - V' I I i i I I I I I I i i I I I I I I i i I I I I I I i I I I I I I i I I I I I I i I I I I I i I I I I I I I i I I I I i I I I I i I I I I i I i I I I i I i O I 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_1 Yr Rain Event Britton Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 18 Summary for Reach DPP: Design Point Summation - Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.247 ac, 5.63% Impervious, Inflow Depth > 0.14" Inflow = 1.42 cfs @ 12.77 hrs, Volume= 0.431 of Outflow = 1.42 cfs @ 12.77 hrs, Volume= 0.431 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPP: Design Point Summation - Proposed Hydrograph 1.42 cfs _Inflow Outflow Inflow Area=38.247 ac I I I I I I I I I I I I I I I I I I I I N I I I I I I I I I I V I I I I I I 0 LL I I I I I I I I I I I I I I I I I I I I I I I 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 19 Summary for Pond P 1&2: Dry Pond 1 and 2 Inflow Area = 7.934 ac, 12.61% Impervious, Inflow Depth > 0.40" Inflow = 2.81 cfs @ 12.10 hrs, Volume= 0.266 of Outflow = 0.21 cfs @ 15.76 hrs, Volume= 0.132 af, Atten= 93%, Lag= 219.6 min Discarded = 0.08 cfs @ 15.76 hrs, Volume= 0.053 of Primary = 0.12 cfs @ 15.76 hrs, Volume= 0.080 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 963.48' @ 15.76 hrs Surf.Area= 7,220 sf Storage= 6,594 cf Flood Elev= 967.00' Surf.Area= 0 sf Storage= 41,073 cf Plug-Flow detention time= 228.7 min calculated for 0.132 of(50% of inflow) Center-of-Mass det. time= 130.7 min ( 965.2 - 834.5 ) Volume Invert Avail.Storage Storage Description #1 962.00' 41,073 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 962.00 2,481 0 0 963.00 4,866 3,674 3,674 964.00 9,737 7,302 10,975 965.00 10,123 9,930 20,905 966.00 15,106 12,615 33,520 967.00 0 7,553 41,073 Device Routing Invert Outlet Devices #1 Discarded 962.00' 0.500 in/hr Exfiltration over Surface area #2 Primary 962.00' 15.0" Round Culvert L= 53.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 962.00' /961.70' S= 0.0057 '/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #3 Device 2 962.00' 2.0"Vert. Orifice/Grate C= 0.600 #4 Device 2 964.72' 12.0" Vert. Orifice/Grate C= 0.600 #5 Device 2 965.00' 18.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.08 cfs @ 15.76 hrs HW=963.48' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.08 cfs) Primary OutFlow Max=0.12 cfs @ 15.76 hrs HW=963.48' (Free Discharge) t2=Culvert (Passes 0.12 cfs of 4.32 cfs potential flow) 13=Orifice/Grate (Orifice Controls 0.12 cfs @ 5.70 fps) 4=Orifice/G rate ( Controls 0.00 cfs) 5=Orifice/Grate ( Controls 0.00 cfs) Britton-1 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=1.99" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 20 Pond P 1&2: Dry Pond 1 and 2 Hydrograph 2.81 cfs LDiscard]edd Inflow Area=7.934 ac Peak Elev=963.48' 2 --- -- Storage=6,594 cf N O LL ------'i---------- 0.12 cfs 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 1 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 13.361 65 2 acre lots, 12% imp, HSG B (EOS1, OSC 1) 5.856 77 2 acre lots, 12% imp, HSG C (EOS1, EOS3, OSC 1, OSC-3) 6.934 74 >75% Grass cover, Good, HSG C (PSC-1, PSC-2) 1.001 98 Paved parking, rooftops, road, HSG C (PSC-1, PSC-2) 17.255 58 Woods/grass comb., Good, HSG B (EOS1, ESC, OSC 1, OSC-2) 32.104 72 Woods/grass comb., Good, HSG C (EOS1, EOS3, ESC, OSC 1, OSC-2, OSC-3) 76.510 69 TOTAL AREA Britton_10 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 2 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 13.361 5.856 0.000 0.000 19.216 2 acre lots, 12% imp EOS1 EOS3 OSC 1, OSC- 3 0.000 0.000 6.934 0.000 0.000 6.934 >75% Grass cover, Good PSC- 1, PSC- 2 0.000 0.000 1.001 0.000 0.000 1.001 Paved parking, rooftops, road PSC- 1, PSC- 2 0.000 17.255 32.104 0.000 0.000 49.359 Woods/grass comb., Good EOS1 EOS3 ESC, OSC 1, OSC- 2, OSC- 3 0.000 30.616 45.894 0.000 0.000 76.510 TOTAL AREA Britton_10 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 3 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 24" Culvert 961.50 961.30 64.0 0.0031 0.013 24.0 0.0 0.0 2 P 1&2 962.00 961.70 53.0 0.0057 0.013 15.0 0.0 0.0 Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 4 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEOS1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>0.73" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=5.35 cfs 0.897 of SubcatchmentEOS3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>1.10" Flow Length=606' Tc=32.5 min CN=75 Runoff=1.57 cfs 0.150 of SubcatchmentESC: Existing Runoff Area=950,525 sf 0.00% Impervious Runoff Depth>0.69" Flow Length=1,606' Tc=50.9 min CN=67 Runoff=8.61 cfs 1.249 of SubcatchmentOSC 1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>0.73" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=5.35 cfs 0.897 of SubcatchmentOSC-2: Off-Site Runoff Area=604,235 sf 0.00% Impervious Runoff Depth>0.60" Flow Length=2,344' Tc=41.3 min CN=65 Runoff=5.31 cfs 0.698 of SubcatchmentOSC-3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>1.10" Flow Length=606' Tc=32.5 min CN=75 Runoff=1.57 cfs 0.150 of SubcatchmentPSC-1: Proposed Runoff Area=147,569 sf 15.15% Impervious Runoff Depth>1.29" Flow Length=1,041' Tc=12.4 min CN=78 Runoff=6.71 cfs 0.366 of SubcatchmentPSC-2: Proposed Runoff Area=198,047 sf 10.72% Impervious Runoff Depth>1.22" Flow Length=979' Tc=28.8 min CN=77 Runoff=5.31 cfs 0.464 of Reach 24" Culvert:24" Culvert Avg. Flow Depth=0.97' Max Vet=3.98 fps Inflow=6.02 cfs 1.047 of 24.0" Round Pipe n=0.013 L=64.0' S=0.0031 T Capacity=12.65 cfs Outflow=6.01 cfs 1.046 of Reach DPE: Design Point Summation- Existing Inflow=14.48 cfs 2.297 of Outflow=14.48 cfs 2.297 of Reach DPP: Design Point Summation- Proposed Inflow=10.92 cfs 2.048 of Outflow=10.92 cfs 2.048 of Pond P 1&2: Dry Pond 1 and 2 Peak Elev=965.06' Storage=21,567 cf Inflow=9.92 cfs 0.829 of Discarded=0.12 cfs 0.082 of Primary=0.92 cfs 0.303 of Outflow=1.05 cfs 0.385 of Total Runoff Area = 76.510 ac Runoff Volume = 4.871 of Average Runoff Depth = 0.76" 95.68% Pervious = 73.203 ac 4.32% Impervious = 3.307 ac Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment EOS1: Off-Site Subcatchment 1 Runoff = 5.35 cfs @ 12.75 hrs, Volume= 0.897 af, Depth> 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment EOS1: Off-Site Subcatchment 1 Hydrograph 5.35 cfs —Runoff 5- Type 11 24-h r Rainfall=3.40" 4 Runoff Area=645,339 sf -- y Runoff Volume=0.897 of U 3 Runoff Depth>0.73" Flow Length=2,082' 2= Tc=63.8 m i n CN=68 1- 0- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment EOS3: Off-Site Subcatchment 3 Runoff = 1.57 cfs @ 12.29 hrs, Volume= 0.150 af, Depth> 1.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment EOS3: Off-Site Subcatchment 3 Hydrograph 1.57 cfs —Runoff Type 11 24-hr Rainfall=3.40" Runoff Area=70,850 sf w Runoff'Volume=0.150 of Runoff Depth>1 .10" LL Flow Length=606' Tc=32.5 m i n CN=75 o 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment ESC: Existing Subcatchment Runoff = 8.61 cfs @ 12.58 hrs, Volume= 1.249 af, Depth> 0.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 334,278 58 Woods/grass comb., Good, HSG B 616,247 72 Woods/grass comb., Good, HSG C 950,525 67 Weighted Average 950,525 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.6 150 0.0700 0.13 Sheet Flow, First 150' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 31.3 1,456 0.0240 0.77 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 50.9 1,606 Total Subcatchment ESC: Existing Subcatchment Hydrograph 9- -------- -------------- 8.61cfs --- -----,---- ---- ' -------- --- —Runoff 8- Type 11 24-h r Rainfall=3.40" Runoff Area=950,525 sf y Runoff Volume=1 .249 of 3 5 Runoff Depth>0.69" U. 4- Flow Length=1,606' 3 Tc=50.9 min 2- CN=67 1 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment OSC 1: Off-Site Subcatchment 1 Runoff = 5.35 cfs @ 12.75 hrs, Volume= 0.897 af, Depth> 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment OSC 1: Off-Site Subcatchment 1 Hydrograph 5.35 cfs —Runoff 5- Type 11 24-h r Rainfall=3.40" 4 Runoff Area=645,339 sf -- y Runoff Volume=0.897 of U 3 Runoff Depth>0.73" Flow Length=2,082' 2= Tc=63.8 m i n CN=68 1- 0- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 1124-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment OSC-2: Off-Site Subcatchment 2 Runoff = 5.31 cfs @ 12.45 hrs, Volume= 0.698 af, Depth> 0.60" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 287,733 58 Woods/grass comb., Good, HSG B 316,502 72 Woods/grass comb., Good, HSG C 604,235 65 Weighted Average 604,235 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.2 100 0.0700 0.12 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 24.2 1,102 0.0230 0.76 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 2.9 1,142 0.0180 6.51 65.06 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 & 0.0 7' Top.W=8.00' n= 0.030 41.3 2,344 Total Subcatchment OSC-2: Off-Site Subcatchment 2 Hydrograph 5.31 cfs —Runoff 5 Type II 24-hr Rainfall=3.40" 4_ Runoff Area=604,235 sf y Runoff Volume=0.698 of U 3- Runoff Depth>0.60' LL Flow Length=2,344' 2- ------------- ---- --- -- Tc=41 .-3-min- CN=65 1- 0- . 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment OSC-3: Off-Site Subcatchment 3 Runoff = 1.57 cfs @ 12.29 hrs, Volume= 0.150 af, Depth> 1.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment OSC-3: Off-Site Subcatchment 3 Hydrograph 1.57 cfs —Runoff Type 11 24-hr Rainfall=3.40" Runoff Area=70,850 sf w Runoff'Volume=0.150 of Runoff Depth>1 .10" LL Flow Length=606' Tc=32.5 m i n CN=75 o 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 1124-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 11 Summary for Subcatchment PSC-1: Proposed Subcatchment 1 Runoff = 6.71 cfs @ 12.05 hrs, Volume= 0.366 af, Depth> 1.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 22,354 98 Paved parking, rooftops, road, HSG C 125,215 74 >75% Grass cover, Good, HSG C 147,569 78 Weighted Average 125,215 84.85% Pervious Area 22,354 15.15% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.0500 0.15 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 0.5 43 0.0480 1.53 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 0.2 25 0.0150 2.49 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 0.9 873 0.0180 16.26 260.24 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 7' Top.W=14.00' n= 0.013 12.4 1,041 Total Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 12 Subcatchment PSC-1: Proposed Subcatchment 1 Hydrograph 7- 6.71 cfs —Runoff 6-. Type 11 24-hr Rainfall=3.40" 5- -------- ----------- ---- R-unoff-Area=147;569af y Runoff Volume=0.366 of 4- 3 Runoff Depth>1 .29" 3- Flow Length=1 ,041' Tc=12.4 min 2- CN=78 1 0- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 13 Summary for Subcatchment PSC-2: Proposed Subcatchment 2 Runoff = 5.31 cfs @ 12.24 hrs, Volume= 0.464 af, Depth> 1.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=3.40" Area (sf) CN Description 21,230 98 Paved parking, rooftops, road, HSG C 176,817 74 >75% Grass cover, Good, HSG C 198,047 77 Weighted Average 176,817 89.28% Pervious Area 21,230 10.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.2 100 0.0300 0.13 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 15.6 879 0.0180 0.94 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 28.8 979 Total Subcatchment PSC-2: Proposed Subcatchment 2 Hydrograph 5.31 cfs —Runoff 5- Type 11 24-hr Rainfall=3.40" 4 ------- ------------------ ---- -- � Runoff Area=198,047 sf w Runoff'Volume=0.464 of 3- Runoff Depth>1 .22" Flow Length=979' 2- Tc=28.8 m i n CN=77 1 --------------------------- --- ---- --------- -------- ----------- 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 14 Summary for Reach 24" Culvert: 24" Culvert [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 16.441 ac, 7.01% Impervious, Inflow Depth > 0.76" Inflow = 6.02 cfs @ 12.70 hrs, Volume= 1.047 of Outflow = 6.01 cfs @ 12.71 hrs, Volume= 1.046 af, Atten= 0%, Lag= 0.4 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.98 fps, Min. Travel Time= 0.3 min Avg. Velocity = 2.27 fps, Avg. Travel Time= 0.5 min Peak Storage= 97 cf @ 12.70 hrs Average Depth at Peak Storage= 0.97' Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 12.65 cfs 24.0" Round Pipe n= 0.013 Length= 64.0' Slope= 0.0031 T Inlet Invert= 961.50', Outlet Invert= 961.30' Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 15 Reach 24" Culvert: 24" Culvert Hydrograph 6.01 cfs Inflow 6 —Outflow Inflow Area=16.441 ac 5- Avg. Flow Depth=0.97- - - - - - - - - - - - - -- - - - Max Vet=3.98 fps 4 24.099 N 3 Round Pipe 0 LL 3- n=0.013 L=64.0' 2- S=0.0031 T 1- Capacity=12.65 cfs 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 16 Summary for Reach DPE: Design Point Summation - Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.262 ac, 3.01% Impervious, Inflow Depth > 0.72" Inflow = 14.48 cfs @ 12.61 hrs, Volume= 2.297 of Outflow = 14.48 cfs @ 12.61 hrs, Volume= 2.297 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPE: Design Point Summation - Existing Hydrograph 16- - - - - 15- 14.48 cfs —Inflow —Outflow Inflow Airea=38.262 acl-- 13- --I---- ----r-------------r------- - - - - - - - - - - - - - I - I I I I I 12 - - - -' -- - - -L--------J----L----'-- - - - - I I I I I I I I I I I I I I 10 - - - - - - - - - --L--------!--- ----'- -- ---L- - - - - _ I I -J- -L- -I- - -L- -J- - -'-- L- 7 ---r----I- -- - -r- ------ ---- - I 6- - - - - - - - - - - - - - I -JI--------------' --- - - - - - !- - - - - - - - - - - - - - - - - I I I I I I I - I I I I I I I 5 --- ---- ---- ------------- ---- ---- ----r---- ,---- --- - - - - -- - - - i 4- - - - - - - - - - '- - - - - - - -' ----- - - - - -- - - - - - - - - - - - - - - - - - --- - - - 3 --r----li ---,----Ir- -Ir--- --- I I I I I I I I I I 2 ----I---------L---- ---J----L---- --------L----I-- J- ------I--------- I I I I I 1 r ----r ----r-------- -- ------ 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 17 Summary for Reach DPP: Design Point Summation - Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.247 ac, 5.63% Impervious, Inflow Depth > 0.64" Inflow = 10.92 cfs @ 12.54 hrs, Volume= 2.048 of Outflow = 10.92 cfs @ 12.54 hrs, Volume= 2.048 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPP: Design Point Summation - Proposed Hydrograph 11 - - - - - - - - - - -10- - - - - - - - - - - - - - - - - - - - —Inflow - - - - - - - - - �- - - - - —Outflow 10= Inflow Area=38.247 ace 9- w 7 0 6_--------------'I---------- --------------- ---'I---------- -------------- ---- LL 4- 3- - - - -- - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - 2- 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_10 Yr Rain Event Britton_Model Type 1124-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 18 Summary for Pond P 1&2: Dry Pond 1 and 2 Inflow Area = 7.934 ac, 12.61% Impervious, Inflow Depth > 1.25" Inflow = 9.92 cfs @ 12.08 hrs, Volume= 0.829 of Outflow = 1.05 cfs @ 13.48 hrs, Volume= 0.385 af, Atten= 89%, Lag= 84.0 min Discarded = 0.12 cfs @ 13.48 hrs, Volume= 0.082 of Primary = 0.92 cfs @ 13.48 hrs, Volume= 0.303 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 965.06' @ 13.48 hrs Surf.Area= 10,444 sf Storage= 21,567 cf Flood Elev= 967.00' Surf.Area= 0 sf Storage= 41,073 cf Plug-Flow detention time= 208.5 min calculated for 0.383 of(46% of inflow) Center-of-Mass det. time= 123.2 min ( 933.4 - 810.2 ) Volume Invert Avail.Storage Storage Description #1 962.00' 41,073 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 962.00 2,481 0 0 963.00 4,866 3,674 3,674 964.00 9,737 7,302 10,975 965.00 10,123 9,930 20,905 966.00 15,106 12,615 33,520 967.00 0 7,553 41,073 Device Routing Invert Outlet Devices #1 Discarded 962.00' 0.500 in/hr Exfiltration over Surface area #2 Primary 962.00' 15.0" Round Culvert L= 53.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 962.00' /961.70' S= 0.0057 '/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #3 Device 2 962.00' 2.0"Vert. Orifice/Grate C= 0.600 #4 Device 2 964.72' 12.0" Vert. Orifice/Grate C= 0.600 #5 Device 2 965.00' 18.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.12 cfs @ 13.48 hrs HW=965.06' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.12 cfs) Primary OutFlow Max=0.91 cfs @ 13.48 hrs HW=965.06' (Free Discharge) t2=Culvert (Passes 0.91 cfs of 7.29 cfs potential flow) 13=Orifice/Grate (Orifice Controls 0.18 cfs @ 8.31 fps) 4=Orifice/G rate (Orifice Controls 0.48 cfs @ 2.00 fps) 5=Orifice/Grate (Weir Controls 0.25 cfs @ 0.83 fps) Britton_10 Yr Rain Event Britton Model Type 11 24-hr Rainfall=3.40" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 19 Pond P 1&2: Dry Pond 1 and 2 Hydrograph 9.92 cfs —Inflow 10-- --- --- -- --- --- I Outflow A —Discarded ' -Inflow Area=7.934- ac —Primary 8 - - - +--- - ---- --- --Peak Elev=965.016. - I I I I I ttorage=21 -,%7-ief I I I I I - I � � I I I I I I I I O _ l.L - --------' --------L--- ---------L---- ----L-------- ----'- 3 -�� I I I I I I I 0.92 cfs 1T------ --'i 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 1 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 13.361 65 2 acre lots, 12% imp, HSG B (EOS1, OSC 1) 5.856 77 2 acre lots, 12% imp, HSG C (EOS1, EOS3, OSC 1, OSC-3) 6.934 74 >75% Grass cover, Good, HSG C (PSC-1, PSC-2) 1.001 98 Paved parking, rooftops, road, HSG C (PSC-1, PSC-2) 17.255 58 Woods/grass comb., Good, HSG B (EOS1, ESC, OSC 1, OSC-2) 32.104 72 Woods/grass comb., Good, HSG C (EOS1, EOS3, ESC, OSC 1, OSC-2, OSC-3) 76.510 69 TOTAL AREA Britton_25 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 2 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 13.361 5.856 0.000 0.000 19.216 2 acre lots, 12% imp EOS1 EOS3 OSC 1, OSC- 3 0.000 0.000 6.934 0.000 0.000 6.934 >75% Grass cover, Good PSC- 1, PSC- 2 0.000 0.000 1.001 0.000 0.000 1.001 Paved parking, rooftops, road PSC- 1, PSC- 2 0.000 17.255 32.104 0.000 0.000 49.359 Woods/grass comb., Good EOS1 EOS3 ESC, OSC 1, OSC- 2, OSC- 3 0.000 30.616 45.894 0.000 0.000 76.510 TOTAL AREA Britton_25 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 3 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 24" Culvert 961.50 961.30 64.0 0.0031 0.013 24.0 0.0 0.0 2 P 1&2 962.00 961.70 53.0 0.0057 0.013 15.0 0.0 0.0 Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 4 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEOS1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>1.18" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=9.27 cfs 1.456 of SubcatchmentEOS3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>1.66" Flow Length=606' Tc=32.5 min CN=75 Runoff=2.40 cfs 0.225 of SubcatchmentESC: Existing Runoff Area=950,525 sf 0.00% Impervious Runoff Depth>1.13" Flow Length=1,606' Tc=50.9 min CN=67 Runoff=15.18 cfs 2.050 of SubcatchmentOSC 1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>1.18" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=9.27 cfs 1.456 of SubcatchmentOSC-2: Off-Site Runoff Area=604,235 sf 0.00% Impervious Runoff Depth>1.02" Flow Length=2,344' Tc=41.3 min CN=65 Runoff=9.84 cfs 1.176 of SubcatchmentOSC-3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>1.66" Flow Length=606' Tc=32.5 min CN=75 Runoff=2.40 cfs 0.225 of SubcatchmentPSC-1: Proposed Runoff Area=147,569 sf 15.15% Impervious Runoff Depth>1.89" Flow Length=1,041' Tc=12.4 min CN=78 Runoff=9.80 cfs 0.535 of SubcatchmentPSC-2: Proposed Runoff Area=198,047 sf 10.72% Impervious Runoff Depth>1.81" Flow Length=979' Tc=28.8 min CN=77 Runoff=7.93 cfs 0.685 of Reach 24" Culvert:24" Culvert Avg. Flow Depth=1.37' Max Vet=4.49 fps Inflow=10.29 cfs 1.680 of 24.0" Round Pipe n=0.013 L=64.0' S=0.0031 T Capacity=12.65 cfs Outflow=10.29 cfs 1.680 of Reach DPE: Design Point Summation- Existing Inflow=25.23 cfs 3.731 of Outflow=25.23 cfs 3.731 of Reach DPP: Design Point Summation- Proposed Inflow=23.93 cfs 3.528 of Outflow=23.93 cfs 3.528 of Pond P 1&2: Dry Pond 1 and 2 Peak Elev=965.36' Storage=24,835 cf Inflow=14.74 cfs 1.219 of Discarded=0.14 cfs 0.087 of Primary=4.91 cfs 0.672 of Outflow=5.05 cfs 0.759 of Total Runoff Area = 76.510 ac Runoff Volume = 7.806 of Average Runoff Depth = 1.22" 95.68% Pervious = 73.203 ac 4.32% Impervious = 3.307 ac Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment EOS1: Off-Site Subcatchment 1 Runoff = 9.27 cfs @ 12.72 hrs, Volume= 1.456 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment EOS1: Off-Site Subcatchment 1 Hydrograph 10- 9.27 cfs —Runoff 9 Type II 24-hr 8 Rainfall=4.22" 7-1 Runoff Area=645,339 sf y 6- Runoff Volume=1 .456 of U 0 5 Runoff Depth>1 .18" 4= Flow Length=2,082' 3= Tc=63.8 m i n 2 CN=68 1- o . . . 5 6 7 8 9 10 11 12 13 7 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment EOS3: Off-Site Subcatchment 3 Runoff = 2.40 cfs @ 12.28 hrs, Volume= 0.225 af, Depth> 1.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment EOS3: Off-Site Subcatchment 3 Hydrograph 2.40 cfs —Runoff Type 11 24_�hr 2- Rainfall=4.2'2" Runoff Area=70,850 sf w Runoff'Volume=0.225 of Runoff Depth>1 .66" LL 1 ------- - ' ---- --- -'-- Flow Length=606' Tc=32.5 m i n CN=75 0 5 (i 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment ESC: Existing Subcatchment Runoff = 15.18 cfs @ 12.55 hrs, Volume= 2.050 af, Depth> 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 334,278 58 Woods/grass comb., Good, HSG B 616,247 72 Woods/grass comb., Good, HSG C 950,525 67 Weighted Average 950,525 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.6 150 0.0700 0.13 Sheet Flow, First 150' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 31.3 1,456 0.0240 0.77 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 50.9 1,606 Total Subcatchment ESC: Existing Subcatchment Hydrograph 16- 15.18 cfs —Runoff 15 14 Type II 24-hr 13- Rainfall=4.22" 12 11- Runoff Area=950,525 sf 10. Runoff volume=2.050 of - v 9_ 0 8- Runoff Depth>1 .13" LL 7 Flow Length=1 ,606' 6- 5- Tc=50.9 m i n 4= CN=67 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3 2- - - - -,- - - - - - - - ------------------- ----------- - ----------- --- --------- 1- 0= 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment OSC 1: Off-Site Subcatchment 1 Runoff = 9.27 cfs @ 12.72 hrs, Volume= 1.456 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment OSC 1: Off-Site Subcatchment 1 Hydrograph 10- 9.27 cfs —Runoff 9 Type II 24-hr 8 Rainfall=4.22" 7-1 Runoff Area=645,339 sf y 6- Runoff Volume=1 .456 of U 0 5 Runoff Depth>1 .18" 4= Flow Length=2,082' 3= Tc=63.8 m i n 2 CN=68 1- o . . . 5 6 7 8 9 10 11 12 13 7 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 1124-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment OSC-2: Off-Site Subcatchment 2 Runoff = 9.84 cfs @ 12.43 hrs, Volume= 1.176 af, Depth> 1.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 287,733 58 Woods/grass comb., Good, HSG B 316,502 72 Woods/grass comb., Good, HSG C 604,235 65 Weighted Average 604,235 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.2 100 0.0700 0.12 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 24.2 1,102 0.0230 0.76 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 2.9 1,142 0.0180 6.51 65.06 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 & 0.0 7' Top.W=8.00' n= 0.030 41.3 2,344 Total Subcatchment OSC-2: Off-Site Subcatchment 2 Hydrograph 11- - 10- 9.84 cfs —Runoff 9- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Type- 11 24-hr- 8- Rainfall=4.22" 7 - Runoff Area=604,235 sf H Runoff Volume=1 .176 of 6- 0 5 Runoff Depth>1 .02" i10 - Flow Length=2,344' 4- Tc=41 .3 m i n 3- CN=65 2_ 0- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment OSC-3: Off-Site Subcatchment 3 Runoff = 2.40 cfs @ 12.28 hrs, Volume= 0.225 af, Depth> 1.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment OSC-3: Off-Site Subcatchment 3 Hydrograph 2.40 cfs —Runoff Type 11 24,hr 2- Rainfall=4.2':2 Runoff Area=70,850 sf w Runoff'Volume=0.225 of Runoff Depth>1 .66" LL 1 -- ---- ' ---- --- -'-- Flow Length=606' Tc=32.5 m i n CN=75 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 1124-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 11 Summary for Subcatchment PSC-1: Proposed Subcatchment 1 Runoff = 9.80 cfs @ 12.05 hrs, Volume= 0.535 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 22,354 98 Paved parking, rooftops, road, HSG C 125,215 74 >75% Grass cover, Good, HSG C 147,569 78 Weighted Average 125,215 84.85% Pervious Area 22,354 15.15% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.0500 0.15 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 0.5 43 0.0480 1.53 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 0.2 25 0.0150 2.49 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 0.9 873 0.0180 16.26 260.24 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 7' Top.W=14.00' n= 0.013 12.4 1,041 Total Britton_25 Yr Rain Event Britton Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 12 Subcatchment PSC-1: Proposed Subcatchment 1 Hydrograph 10- 9.80 cfs —Runoff 9_ Type II 24hr_ _ - - - - - - - Rainfall=4.2'',2" 7 - - - - - - - - - - - - - - - - - - - --I - - - - -- Runof#Area=147,569'_sf cn 6= !---- Runoff_Vol --- - -V ume-o.535 Runoff De th 1 .8 = II --- -- - -- -- .2 5 LL Flow Length=1 ,041' - 4 - - - - - - - - - - - - -------------i--- ------- ----i Tc=12.4 min 3 -------------- ' ------------- ' --- '- ------- ----,.----'--- - ---- CN=18 - - - - -- -- -- ---- 0= 1 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 13 Summary for Subcatchment PSC-2: Proposed Subcatchment 2 Runoff = 7.93 cfs @ 12.24 hrs, Volume= 0.685 af, Depth> 1.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.22" Area (sf) CN Description 21,230 98 Paved parking, rooftops, road, HSG C 176,817 74 >75% Grass cover, Good, HSG C 198,047 77 Weighted Average 176,817 89.28% Pervious Area 21,230 10.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.2 100 0.0300 0.13 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 15.6 879 0.0180 0.94 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 28.8 979 Total Subcatchment PSC-2: Proposed Subcatchment 2 Hydrograph 7.93 cfs —Runoff 8 Type 11 24-hr 7- Rai nfall=4.2'2" 6 Runoff Area=198,047 sf Z. 5- ,Runoff'Volume=0.685 of 3 Runoff Depth>1 .81" 0 4_ LL Flow Length=979' 3- Tc=28.8 m i n 2 CN=77 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 14 Summary for Reach 24" Culvert: 24" Culvert [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area = 16.441 ac, 7.01% Impervious, Inflow Depth > 1.23" Inflow = 10.29 cfs @ 12.68 hrs, Volume= 1.680 of Outflow = 10.29 cfs @ 12.69 hrs, Volume= 1.680 af, Atten= 0%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.49 fps, Min. Travel Time= 0.2 min Avg. Velocity = 2.41 fps, Avg. Travel Time= 0.4 min Peak Storage= 147 cf @ 12.69 hrs Average Depth at Peak Storage= 1.37' Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 12.65 cfs 24.0" Round Pipe n= 0.013 Length= 64.0' Slope= 0.0031 T Inlet Invert= 961.50', Outlet Invert= 961.30' Britton_25 Yr Rain Event Britton Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 15 Reach 24" Culvert: 24" Culvert Hydrograph 11 -----I--- ------- i 10.29 cfs —Inflow —Outflow Inflow Area=16.441 ac v�g. FIovW-De - A -- - 8 ----- --- --- MIx Vel= .-49-;fps 7 -2-4'-0"----- ------ --- ------- ----- ----- Rdund Pipe ---- - -- --- -------- ---- - LL 5 n=0.013 --------7----F----I---- ;---------7----F----I---- 4 -L=64.0' L----'---- --- ---- ---=-- - -- 3- - S#0.0031-'P--- --- --- --- ---- - ---- --- - ---------- 2 -Cgpacity=42.65-c#s--- ---- --- --'-- 1 - -- ------ - --r--- ------------- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 16 Summary for Reach DPE: Design Point Summation - Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.262 ac, 3.01% Impervious, Inflow Depth > 1.17" Inflow = 25.23 cfs @ 12.59 hrs, Volume= 3.731 of Outflow = 25.23 cfs @ 12.59 hrs, Volume= 3.731 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPE: Design Point Summation - Existing Hydrograph 28- 26- 25.23 cfs _Inflow Outflow 24 Inflow Area=38262 ac 22- 20- 18- w16- -- - - - - - - - - - - - - - - - - - - - - - - - - -'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - w 3 14- 0 LL12 - - - - - - - - - - - - - - - - - - - - - -,- - - -- - - - - - - - - - - - - - - - - - 10- 8- 6 - - - - - - - - - - - - - - - I 4- 2- 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 17 Summary for Reach DPP: Design Point Summation - Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.247 ac, 5.63% Impervious, Inflow Depth > 1.11" Inflow = 23.93 cfs @ 12.53 hrs, Volume= 3.528 of Outflow = 23.93 cfs @ 12.53 hrs, Volume= 3.528 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPP: Design Point Summation - Proposed Hydrograph 26 25 23.93 cfs —Inflow 24` —Outflow 22 Inflow Area=38.247 ac 21= 20` - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - 19 18= 17 - - - - - - - - - 16- --------- ---- --- - ----- -- - - - - - -- ---- --------- ------------------ w 15= 14 ° 12 --------- ------------- -------------- --- -------- ------------- - - - - - LL 11 10-- -- - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9- 8-8 -- - - - -- - - - - - - - - - - - - - - - - - - - - - -- '- - - - - - - - - - - - - - - - - 7- 6- - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - -'- - - - - - - - - 5 4 -- - - - - - - - - ' 3_ 2_ - - - - - - - - - - - - - - - - - - - - - - - - - - - L - - - - - - - - ! - - - - - 0-- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton_25 Yr Rain Event Britton_Model Type 1124-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 18 Summary for Pond P 1&2: Dry Pond 1 and 2 Inflow Area = 7.934 ac, 12.61% Impervious, Inflow Depth > 1.84" Inflow = 14.74 cfs @ 12.08 hrs, Volume= 1.219 of Outflow = 5.05 cfs @ 12.56 hrs, Volume= 0.759 af, Atten= 66%, Lag= 29.0 min Discarded = 0.14 cfs @ 12.56 hrs, Volume= 0.087 of Primary = 4.91 cfs @ 12.56 hrs, Volume= 0.672 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 965.36' @ 12.56 hrs Surf.Area= 11,901 sf Storage= 24,835 cf Flood Elev= 967.00' Surf.Area= 0 sf Storage= 41,073 cf Plug-Flow detention time= 145.0 min calculated for 0.759 of(62% of inflow) Center-of-Mass det. time= 70.4 min ( 872.7 - 802.3 ) Volume Invert Avail.Storage Storage Description #1 962.00' 41,073 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 962.00 2,481 0 0 963.00 4,866 3,674 3,674 964.00 9,737 7,302 10,975 965.00 10,123 9,930 20,905 966.00 15,106 12,615 33,520 967.00 0 7,553 41,073 Device Routing Invert Outlet Devices #1 Discarded 962.00' 0.500 in/hr Exfiltration over Surface area #2 Primary 962.00' 15.0" Round Culvert L= 53.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 962.00' /961.70' S= 0.0057 '/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #3 Device 2 962.00' 2.0"Vert. Orifice/Grate C= 0.600 #4 Device 2 964.72' 12.0" Vert. Orifice/Grate C= 0.600 #5 Device 2 965.00' 18.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.14 cfs @ 12.56 hrs HW=965.36' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.14 cfs) Primary OutFlow Max=4.89 cfs @ 12.56 hrs HW=965.36' (Free Discharge) t2=Culvert (Passes 4.89 cfs of 7.71 cfs potential flow) 13=Orifice/Grate (Orifice Controls 0.19 cfs @ 8.71 fps) 4=Orifice/G rate (Orifice Controls 1.43 cfs @ 2.72 fps) 5=Orifice/Grate (Weir Controls 3.27 cfs @ 1.95 fps) Britton_25 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=4.22" Prepared by {enter your company name here} Printed 8/17/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 19 Pond P 1&2: Dry Pond 1 and 2 Hydrograph 16- 14.74 cfs —Inflow 15= -- - - —Outflow —Discarded 14 - --- inflow-Area=7.934 ac -Primary 13 ---- - 12= - --- --- Peak Elev=965.36' 10 ___ __ Storage=24,835 cf w9- - - - - - - - - - - - - - - - - - - - - - - - - - - ---- -- - - - - - -- - - - - - - - - - - - - - - ---- -- - - - - 3 8- --- 6= ----'---- ----------------- 4.91 cfs 4- &cfs --� 2- --'- --1 ------1----L---1----L--- 1- -- - - - - - --i - - - ------- ---r--- 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 1 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 13.361 65 2 acre lots, 12% imp, HSG B (EOS1, OSC 1) 5.856 77 2 acre lots, 12% imp, HSG C (EOS1, EOS3, OSC 1, OSC-3) 6.934 74 >75% Grass cover, Good, HSG C (PSC-1, PSC-2) 1.001 98 Paved parking, rooftops, road, HSG C (PSC-1, PSC-2) 17.255 58 Woods/grass comb., Good, HSG B (EOS1, ESC, OSC 1, OSC-2) 32.104 72 Woods/grass comb., Good, HSG C (EOS1, EOS3, ESC, OSC 1, OSC-2, OSC-3) 76.510 69 TOTAL AREA Britton 100 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 2 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 13.361 5.856 0.000 0.000 19.216 2 acre lots, 12% imp EOS1 EOS3 OSC 1, OSC- 3 0.000 0.000 6.934 0.000 0.000 6.934 >75% Grass cover, Good PSC- 1, PSC- 2 0.000 0.000 1.001 0.000 0.000 1.001 Paved parking, rooftops, road PSC- 1, PSC- 2 0.000 17.255 32.104 0.000 0.000 49.359 Woods/grass comb., Good EOS1 EOS3 ESC, OSC 1, OSC- 2, OSC- 3 0.000 30.616 45.894 0.000 0.000 76.510 TOTAL AREA Britton 100 Yr Rain Event Britton Model Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 3 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 24" Culvert 961.50 961.30 64.0 0.0031 0.013 24.0 0.0 0.0 2 P 1&2 962.00 961.70 53.0 0.0057 0.013 15.0 0.0 0.0 Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 4 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEOS1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>2.23" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=18.31 cfs 2.750 of SubcatchmentEOS3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>2.88" Flow Length=606' Tc=32.5 min CN=75 Runoff=4.20 cfs 0.390 of SubcatchmentESC: Existing Runoff Area=950,525 sf 0.00% Impervious Runoff Depth>2.16" Flow Length=1,606' Tc=50.9 min CN=67 Runoff=30.61 cfs 3.922 of SubcatchmentOSC 1: Off-Site Runoff Area=645,339 sf 7.03% Impervious Runoff Depth>2.23" Flow Length=2,082' Tc=63.8 min CN=68 Runoff=18.31 cfs 2.750 of SubcatchmentOSC-2: Off-Site Runoff Area=604,235 sf 0.00% Impervious Runoff Depth>2.00" Flow Length=2,344' Tc=41.3 min CN=65 Runoff=20.65 cfs 2.314 of SubcatchmentOSC-3: Off-Site Runoff Area=70,850 sf 6.81% Impervious Runoff Depth>2.88" Flow Length=606' Tc=32.5 min CN=75 Runoff=4.20 cfs 0.390 of SubcatchmentPSC-1: Proposed Runoff Area=147,569 sf 15.15% Impervious Runoff Depth>3.18" Flow Length=1,041' Tc=12.4 min CN=78 Runoff=16.25 cfs 0.898 of SubcatchmentPSC-2: Proposed Runoff Area=198,047 sf 10.72% Impervious Runoff Depth>3.07" Flow Length=979' Tc=28.8 min CN=77 Runoff=13.49 cfs 1.163 of Reach 24" Culvert:24" Culvert Avg. Flow Depth=2.00' Max Vet=4.59 fps Inflow=20.08 cfs 3.140 of 24.0" Round Pipe n=0.013 L=64.0' S=0.0031 T Capacity=12.65 cfs Outflow=12.65 cfs 3.139 of Reach DPE: Design Point Summation- Existing Inflow=50.17 cfs 7.062 of Outflow=50.17 cfs 7.062 of Reach DPP: Design Point Summation- Proposed Inflow=45.91 cfs 6.935 of Outflow=45.91 cfs 6.935 of Pond P 1&2: Dry Pond 1 and 2 Peak Elev=966.05' Storage=34,217 cf Inflow=25.09 cfs 2.061 of Discarded=0.17 cfs 0.099 of Primary=8.63 cfs 1.374 of Secondary=3.99 cfs 0.109 of Outflow=12.78 cfs 1.582 of Total Runoff Area = 76.510 ac Runoff Volume = 14.576 of Average Runoff Depth = 2.29" 95.68% Pervious = 73.203 ac 4.32% Impervious = 3.307 ac Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment EOS1: Off-Site Subcatchment 1 Runoff = 18.31 cfs @ 12.70 hrs, Volume= 2.750 af, Depth> 2.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment EOS1: Off-Site Subcatchment 1 Hydrograph 20 19 18.31 cfs —Runoff 18- 17 Type 11 24-hr 15- Rainfall=5.84" '4 Runoff Area=645,339 sf 13: y 12 Runoff Volume=2.750 of 11 0 10 Runoff Depth>2.23" 9- 8_ Flow Length=2,082-- - - - 7=. 6: Tc=63.8 min - - - - - - - - - - - - - - - - - - - - - 5= 4 C N=68 - 3_ 2 - - - - - - - - -- 1 0= 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment EOS3: Off-Site Subcatchment 3 Runoff = 4.20 cfs @ 12.27 hrs, Volume= 0.390 af, Depth> 2.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment EOS3: Off-Site Subcatchment 3 Hydrograph 4.20 cfs —Runoff 4- Type II 24-hr Rainfall=5.8'4" 3_ Runoff Area=70,850 sf w Runoff'Volume=0.390 of Runoff Depth>2.88" LL 2- - ----- ---- -----',--------- ',I---- ---',- Flow Length=606' Tc=32.5 m i n 1- ------ ------------------ --- ---- --------- CN=75 o 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCADO 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment ESC: Existing Subcatchment Runoff = 30.61 cfs @ 12.52 hrs, Volume= 3.922 af, Depth> 2.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 334,278 58 Woods/grass comb., Good, HSG B 616,247 72 Woods/grass comb., Good, HSG C 950,525 67 Weighted Average 950,525 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.6 150 0.0700 0.13 Sheet Flow, First 150' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 31.3 1,456 0.0240 0.77 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 50.9 1,606 Total Subcatchment ESC: Existing Subcatchment Hydrograph 34- - - - - - - - - - - -- - - - - - - - - -Runoff 30 28 Type II 24-hr 26- Rainfall=5.84" 24 22 Runoff Area=950,525 sf y 20 Runoff Volume=3.922 of 18- 0 16- Runoff Depth>2.16" U. 14 Flow Length=1 ,606' 12 101 Tc=50.9 m i n $_ CN=67 6= 4 2 0= 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment OSC 1: Off-Site Subcatchment 1 Runoff = 18.31 cfs @ 12.70 hrs, Volume= 2.750 af, Depth> 2.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 64,812 58 Woods/grass comb., Good, HSG B 87,332 77 2 acre lots, 12% imp, HSG C 290,993 65 2 acre lots, 12% imp, HSG B 202,202 72 Woods/grass comb., Good, HSG C 645,339 68 Weighted Average 599,940 92.97% Pervious Area 45,399 7.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 100 0.0650 0.11 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 49.2 1,982 0.0180 0.67 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 63.8 2,082 Total Subcatchment OSC 1: Off-Site Subcatchment 1 Hydrograph 20' 19 18.31 cfs —Runoff 18- 17 Type 11 24-hr 15- Rainfall=5.84" '4 Runoff Area=645,339 sf 13: y 12 Runoff Volume=2.750 of 11 0 10 Runoff Depth>2.23" 9- 8_ Flow Length=2,082-- - - - 7=. 6: Tc=63.8 min - - - - - - - - - - - - - - - - - - - - - 5= 4 C N=68 - 3_ 2 - - - - - - - - -- 1 0= 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 1124-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment OSC-2: Off-Site Subcatchment 2 Runoff = 20.65 cfs @ 12.41 hrs, Volume= 2.314 af, Depth> 2.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 287,733 58 Woods/grass comb., Good, HSG B 316,502 72 Woods/grass comb., Good, HSG C 604,235 65 Weighted Average 604,235 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.2 100 0.0700 0.12 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 24.2 1,102 0.0230 0.76 Shallow Concentrated Flow, Balance of Flow to Swale Woodland Kv= 5.0 fps 2.9 1,142 0.0180 6.51 65.06 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 & 0.07' Top.W=8.00' n= 0.030 41.3 2,344 Total Subcatchment OSC-2: Off-Site Subcatchment 2 Hydrograph 23- 22 21= 20.65 cfs —Runoff 20 19 Type II 24-hr _ 17 Rainfall=5.8'4" 1 - 15= Runoff Area=604,235 sf 14_ 13= Runoff Volume=2.314 of H 12 c Runoff Depth>2.00"11.' LL 10- - - - - - - - - - - - - Flow Length=2,344'- - 8- - - - - - - - - - - - - - - - - - - - - - Tc=41.3min 6_' - - - - - - - 5 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -CN=65- - 4- 3 2` 1- 0- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment OSC-3: Off-Site Subcatchment 3 Runoff = 4.20 cfs @ 12.27 hrs, Volume= 0.390 af, Depth> 2.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 40,206 77 2 acre lots, 12% imp, HSG C 30,644 72 Woods/grass comb., Good, HSG C 70,850 75 Weighted Average 66,025 93.19% Pervious Area 4,825 6.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 19.9 100 0.0300 0.08 Sheet Flow, First 100' Flowpath Woods: Light underbrush n= 0.400 P2= 2.70" 12.6 506 0.0180 0.67 Shallow Concentrated Flow, Balance of Longest Flowpath Woodland Kv= 5.0 fps 32.5 606 Total Subcatchment OSC-3: Off-Site Subcatchment 3 Hydrograph 4.20 cfs —Runoff 4 Type II 24-hr Rainfall=5.8'4" 3_ Runoff Area=70,850 sf w Runoff'Volume=0.390 of Runoff Depth>2.88" LL 2- - ----- ---- -----',--------- ',I---- ---',- Flow Length=606' Tc=32.5 m i n 1- ------ ------------------ --- ---- --------- CN=75 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 1124-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCADO 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 11 Summary for Subcatchment PSC-1: Proposed Subcatchment 1 Runoff = 16.25 cfs @ 12.04 hrs, Volume= 0.898 af, Depth> 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 22,354 98 Paved parking, rooftops, road, HSG C 125,215 74 >75% Grass cover, Good, HSG C 147,569 78 Weighted Average 125,215 84.85% Pervious Area 22,354 15.15% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.0500 0.15 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 0.5 43 0.0480 1.53 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 0.2 25 0.0150 2.49 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 0.9 873 0.0180 16.26 260.24 Trap/Vee/Rect Channel Flow, Balance of Longest Flowpath Bot.W=2.00' D=2.00' Z= 3.0 '/' Top.W=14.00' n= 0.013 12.4 1,041 Total Britton 100 Yr Rain Event Britton Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 12 Subcatchment PSC-1: Proposed Subcatchment 1 Hydrograph 17- = 16.25cfs I -----' --------- —Runoff --- --- -- T-ypeIt24,hr-- 14 - - - - - ---- ------------- ---- -------- ---- ---Rai-+fall=5:84H- 13- ----1---------1----1-----1----1---- - - ----L----'---p------------- 12- �� � � --- Ru-noft iolrea=147,-569-sf-- ^ Runoff Volume=0. 98-af_ 9_ --- -- -- --- Runoff Depth>3.-1�"- LL8 -----------------------=--- - ------- - - -- - - - - - --------- ------------------- --------- --- 7 � � � �F ---�,-----,-FaQw-Length=1,0- 1'-- 6 - ---, ---- --,--- ------- ----,-- Tc-,1-2-4rein-- 5_ --+-------------+--- i- -------+----+--------- - - - ----F--- 3- --- ',-------------{----i 1 2 - - - i - ---r-------------T-- -r- ------,---------i---- ---------r-- - T i 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCADO 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 13 Summary for Subcatchment PSC-2: Proposed Subcatchment 2 Runoff = 13.49 cfs @ 12.23 hrs, Volume= 1.163 af, Depth> 3.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=5.84" Area (sf) CN Description 21,230 98 Paved parking, rooftops, road, HSG C 176,817 74 >75% Grass cover, Good, HSG C 198,047 77 Weighted Average 176,817 89.28% Pervious Area 21,230 10.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.2 100 0.0300 0.13 Sheet Flow, First 100' Flowpath Grass: Dense n= 0.240 P2= 2.70" 15.6 879 0.0180 0.94 Shallow Concentrated Flow, Balance of Flow to Pavement Short Grass Pasture Kv= 7.0 fps 28.8 979 Total Subcatchment PSC-2: Proposed Subcatchment 2 Hydrograph 15- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - 14 13.49 cfs —Runoff 13= 12= Type II 24�hr 11- Rainfall=5.8'4" 10=----- ----- - ----Runoff Area=198,047-sf- - y --- ---------` - --Runoff Volume=1 .163-af- - 8- o Runoff Depth>3.07" U. 6 Flow Length=979' 5 Tc=28.8 m i n 4_ 3 CN=77 2: 0= 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 14 Summary for Reach 24" Culvert: 24" Culvert [52] Hint: Inlet/Outlet conditions not evaluated [55] Hint: Peak inflow is 159% of Manning's capacity [76] Warning: Detained 0.356 of(Pond w/culvert advised) Inflow Area = 16.441 ac, 7.01% Impervious, Inflow Depth > 2.29" Inflow = 20.08 cfs @ 12.66 hrs, Volume= 3.140 of Outflow = 12.65 cfs @ 12.35 hrs, Volume= 3.139 af, Atten= 37%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.59 fps, Min. Travel Time= 0.2 min Avg. Velocity = 2.54 fps, Avg. Travel Time= 0.4 min Peak Storage= 201 cf @ 12.30 hrs Average Depth at Peak Storage= 2.00' Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 12.65 cfs 24.0" Round Pipe n= 0.013 Length= 64.0' Slope= 0.0031 T Inlet Invert= 961.50', Outlet Invert= 961.30' Britton 100 Yr Rain Event Britton Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 15 Reach 24" Culvert: 24" Culvert Hydrograph 22------- -------- ---------- 21 -------- --- 20.08cfs --',I ----- ---- _Inflow 20------ ------ -------- -- ------- Outflow 19 - i-- - --i---- - In how Area=16.441- ac -- 18 ---- r - 7 1 --1-- -1---- ---r -,- 17 -AVrg. RoW Depth=2.00' --I- -- ----- -------------;-------- ---- 16 ----' I - - -- ---- ---------------------------- 15 -Mix-Vel=4.-59 fps ,---- -- ----' ----;---- ----;-------- ---- 14 - tom- r---- --- - ----r-------- ---- ----i---- ---- 12.65 cfs 13 - r - ------r--------r---- -- --r -r--------r---- ---- r---,---- w 12 -R6un--d-P_- - ----,--- -- - --- ----------------------,---- LL10 -n 0.013 ------------ --- -- --------- ---- --------�--- -- -r----—-------,---- 7 6- -S=*J0031-Ir--- ---- --- --- - --- ---- --- ---- 5 -----I---- - ---'--- - - --------- ---- - - --- ----L-------- '---- 4. -Cal-pacityJ12.65-cf, - - - - 3 ----r-- - - --r - - - - ----r---- --- --- - - - - - -r- - - - - --r - --- ----r--- ---- 1- ----i---- ----' -----ii--- -- -i--- - - - - - - - ----------- 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 16 Summary for Reach DPE: Design Point Summation - Existing [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.262 ac, 3.01% Impervious, Inflow Depth > 2.21" Inflow = 50.17 cfs @ 12.56 hrs, Volume= 7.062 of Outflow = 50.17 cfs @ 12.56 hrs, Volume= 7.062 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPE: Design Point Summation - Existing Hydrograph 55- I I I II 50.17 cfs I I -- -- - - —Inflow Outflow 50- ---- --- -- InfloW AireaT38,,262 acl 45- ------------r---- ---------I-- - - - - - - r - - - - - - - --I---- --------- II 40 ----I----;---- -------- ---------'- -- ----' - I'---------'--------- - � I � i I I � I I I I II 35 --------- ---- ---- ---- ----I- -- ---I ---- ------------------ + 5 30 -- - - - - - - - - -------------------- -- I I I I I 3 I I I I i I i I I I I CZ 25 -- --------L-------- ----L----I ---- ---L-------- ------------------ 20- --------- ----I -------- --- ----I --- - -I - - - - - - - - - - - - - - - - - 15- ----I---- ---- ---------I--- ---- ---',-- -' ----------------------- ---- � i � I 10 --- ---------I -------- ---- ------- ---- ------- --- -------------- I I 5 ---'-- ---- - r 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 11 24-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 17 Summary for Reach DPP: Design Point Summation - Proposed [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 38.247 ac, 5.63% Impervious, Inflow Depth > 2.18" Inflow = 45.91 cfs @ 12.41 hrs, Volume= 6.935 of Outflow = 45.91 cfs @ 12.41 hrs, Volume= 6.935 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach DPP: Design Point Summation - Proposed Hydrograph 50- - - - - - - - - - - - - - - - - - - 48- 45.91 cfs —Inflow 46- —Outflow 44 - - - F - - - - - - - - inflow-Area=38.247 ac 42- 40_ 38- - - - - -- - - - - - - - - - - - -- -- - - - - - - - - - - - - - 36` - - - - - - - - - - - - - - - - - - - - - - - 34- ------ - ------------------------- ------------------ - ----- - - - - - - 32 30= w -- - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - -'- - - - - - - - 26 3 _0 24= LL22 - - - - - - - - - - - - - - - - - - - . - - - - 20 18- 16: - - - - - - - - - - - - - - - - 14- -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12=-----,---- ---- -------- --------- ---- ---- -------- ---- - - - - - - - - - - - - - - 10- 8- 6-8= 6- - - - - - - - - - - - - - - - -,- - - - - - - - - 4 0` 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Britton 100 Yr Rain Event Britton_Model Type 1124-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Page 18 Summary for Pond P 1&2: Dry Pond 1 and 2 Inflow Area = 7.934 ac, 12.61% Impervious, Inflow Depth > 3.12" Inflow = 25.09 cfs @ 12.07 hrs, Volume= 2.061 of Outflow = 12.78 cfs @ 12.41 hrs, Volume= 1.582 af, Atten= 49%, Lag= 20.0 min Discarded = 0.17 cfs @ 12.30 hrs, Volume= 0.099 of Primary = 8.63 cfs @ 12.41 hrs, Volume= 1.374 of Secondary = 3.99 cfs @ 12.41 hrs, Volume= 0.109 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 966.05' @ 12.41 hrs Surf.Area= 14,391 sf Storage= 34,217 cf Flood Elev= 967.00' Surf.Area= 0 sf Storage= 41,073 cf Plug-Flow detention time= 101.3 min calculated for 1.582 of(77% of inflow) Center-of-Mass det. time= 42.7 min ( 833.9 - 791.2 ) Volume Invert Avail.Storage Storage Description #1 962.00' 41,073 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 962.00 2,481 0 0 963.00 4,866 3,674 3,674 964.00 9,737 7,302 10,975 965.00 10,123 9,930 20,905 966.00 15,106 12,615 33,520 967.00 0 7,553 41,073 Device Routing Invert Outlet Devices #1 Discarded 962.00' 0.500 in/hr Exfiltration over Surface area #2 Primary 962.00' 15.0" Round Culvert L= 53.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 962.00' /961.70' S= 0.0057 '/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #3 Device 2 962.00' 2.0" Vert. Orifice/Grate C= 0.600 #4 Device 2 964.72' 12.0" Vert. Orifice/Grate C= 0.600 #5 Device 2 965.00' 18.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #6 Secondary 965.75' 10.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Britton 100 Yr Rain Event Britton_Model Type 1124-hr Rainfall=5.84" Prepared by {enter your company name here} Printed 12/3/2020 HydroCAD® 10.00-21 s/n 01939 ©2018 HydroCAD Software Solutions LLC Pacie 19 4iscarded OutFlow Max=0.17 cfs @ 12.30 hrs HW=965.99' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=8.63 cfs @ 12.41 hrs HW=966.05' (Free Discharge) L =Culvert (Inlet Controls 8.63 cfs @ 7.03 fps) 3=Orifice/Grate (Passes < 0.21 cfs potential flow) =Orifice/Grate (Passes < 3.44 cfs potential flow) 5=Orifice/Grate (Passes < 8.70 cfs potential flow) econdary OutFlow Max=3.95 cfs @ 12.41 hrs HW=966.05' (Free Discharge) =Broad-Crested Rectangular Weir(Weir Controls 3.95 cfs @ 1.34 fps) Pond P 1&2: Dry Pond 1 and 2 Hydrograph 28- 26- 25.09 cfs —Inflow —Outflow —Discarded 24- Inflow Area=7.934 ac —Primary 22- —Secondary 20- - - - - - - - - - - - - - - - - - - - - - - - Peak Elev=966.05' 18= Storage=34,217 cf w 16. 14- - - - -- - - - - - - - - - - - - 12.78cfs - - - - 12- 10: 8.63 cfs 8- - - -- - - 6- 3.99 cfs 4- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2- 0 c 0- . . . . . . . . . . . . . . 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) APPENDIX 3 SOILS DATA USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for States Department of I U RCS Agriculture and other Tompkins 1l Federal agencies, State Natural agencies including the Resources Agricultural Experiment County, New Conservation Stations, and local Service participants York ilk IL AN August 22, 2019 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/ portal/nres/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nres)or your NRCS State Soil Scientist(http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.)should contact USDA's TARGET Center at(202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice)or(202)720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 SoilMap.................................................................................................................. 8 SoilMap................................................................................................................9 Legend................................................................................................................10 MapUnit Legend................................................................................................ 11 MapUnit Descriptions.........................................................................................11 Tompkins County, New York........................................................................... 13 CfA—Conesus gravelly silt loam, 0 to 3 percent slopes..............................13 CfB—Conesus gravelly silt loam, 3 to 8 percent slopes..............................15 IcA—Ilion silty clay loam, 0 to 2 percent slopes.......................................... 17 KnA—Kendaia and Lyons soils, 0 to 3 percent slopes................................18 LbB—Lansing gravelly silt loam, 3 to 8 percent slopes...............................21 Ly—Lyons soils, 0 to 3 percent slopes........................................................23 OaA—Ovid silt loam, 0 to 6 percent slopes.................................................26 References............................................................................................................28 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 Custom Soil Resource Report scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and 6 Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 Custom Soil Resource Report M Soil Map �� 377380 37746D 377540 377620 3T7700 377780 377860 377940 378020 37810D 378180 42°32'9"N Q 42°32'TN X W7671%ik Alk ` All 5. 1. +►3 ,�. ` y3 ` .4, o L A. v I 42-31'52"N - 42'31'52"N 37738D ./46( 377540 37762D 377700 37778D 37786D 377940 378020 378100 378180 3 3 rn m Map Scale:1:3,730If pdr,-�d on A landscape(11"x 8.5")sheet m Meters NN 0 50 100 200 300 i Feet /V 0 150 300 600 900 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 18N WGS84 9 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(AOI) Spoil Area The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 1:20,000. Stony Spot Soils Very Stony Spot Soil Map Unit Polygons Warning:Soil Map may not be valid at this scale. Wet Spot Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause Other misunderstanding of the detail of mapping and accuracy of soil 0 Soil Map Unit Points g PP 9 Y Special Line Features line placement.The maps do not show the small areas of Special Point Features contrasting soils that could have been shown at a more detailed V Blowout Water Features scale. Streams and Canals Borrow Pit Transportation Please rely on the bar scale on each map sheet for map Clay Spot f-F-r Rails measurements. r Closed Depression Interstate Highways Gravel Pit Source of Map: Natural Resources Conservation Service US Routes Web Soil Survey URL: Gravelly Spot Major Roads Coordinate System: Web Mercator(EPSG:3857) 0 Landfill Local Roads Maps from the Web Soil Survey are based on the Web Mercator A. Lava Flow Background projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the Marsh or swamp Aerial Photography Albers equal-area conic projection,should be used if more Mine or Quarry accurate calculations of distance or area are required. 0 Miscellaneous Water This product is generated from the USDA-NRCS certified data as Perennial Water of the version date(s)listed below. IV Rock Outcrop Soil Survey Area: Tompkins County, New York Saline Spot Survey Area Data: Version 14,Sep 3,2018 Sandy Spot Soil map units are labeled(as space allows)for map scales Severely Eroded Spot 1:50,000 or larger. Sinkhole Date(s)aerial images were photographed: Aug 29,2012—Nov Slide or Slip 6,2016 Qa Sodic Spot The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor shifting of map unit boundaries may be evident. 10 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI CfA Conesus gravelly silt loam,0 to 12.7 18.8% 3 percent slopes CfB Conesus gravelly silt loam,3 to 1.7 2.5% 8 percent slopes IcA Ilion silty clay loam,0 to 2 36.5 53.8% percent slopes KnA Kendaia and Lyons soils,0 to 3 13.3 19.6% percent slopes LbB Lansing gravelly silt loam,3 to 8 2.4 3.5% percent slopes Ly Lyons soils,0 to 3 percent 0.7 1.0% slopes OaA Ovid silt loam,0 to 6 percent 0.6 0.9% slopes Totals for Area of Interest 67.8 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit 11 Custom Soil Resource Report descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 12 Custom Soil Resource Report Tompkins County, New York CfA—Conesus gravelly silt loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2w3j2 Elevation: 820 to 1,800 feet Mean annual precipitation: 31 to 57 inches Mean annual air temperature: 41 to 50 degrees F Frost-free period: 100 to 190 days Farmland classification: All areas are prime farmland Map Unit Composition Conesus and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Conesus Setting Landform: Drumlins, ridges, till plains Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Linear Across-slope shape: Convex Parent material: Calcareous loamy lodgment till derived from limestone, sandstone, and shale Typical profile Ap - 0 to 9 inches: gravelly silt loam E/B-9 to 14 inches: gravelly silt loam Bt/E- 14 to 19 inches: gravelly silt loam Bt1 - 19 to 25 inches: gravelly silt loam Bt2-25 to 36 inches: gravelly silt loam C-36 to 79 inches: gravelly loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water(Ksat): Moderately low to moderately high (0.01 to 1.42 in/hr) Depth to water table: About 18 to 24 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: Moderate (about 7.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B/D Hydric soil rating: No 13 Custom Soil Resource Report Minor Components Lansing Percent of map unit: 7 percent Landform: Drumlins, ridges, till plains Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Convex Across-slope shape: Convex Hydric soil rating: No Kendaia Percent of map unit: 3 percent Landform: Till plains, drumlins Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Appleton Percent of map unit: 2 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Nunda Percent of map unit: 2 percent Landform: Hills, drumlinoid ridges Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Concave Across-slope shape: Convex Hydric soil rating: No Lyons Percent of map unit: 1 percent Landform: Drainageways, depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes 14 Custom Soil Resource Report CfB—Conesus gravelly silt loam, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 2w3j3 Elevation: 820 to 1,800 feet Mean annual precipitation: 31 to 57 inches Mean annual air temperature: 41 to 50 degrees F Frost-free period: 100 to 190 days Farmland classification: All areas are prime farmland Map Unit Composition Conesus and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Conesus Setting Landform: Drumlins, hills, till plains Landform position (two-dimensional): Summit, shoulder Landform position (three-dimensional): Crest Down-slope shape: Linear Across-slope shape: Convex Parent material: Calcareous loamy lodgment till derived from limestone, sandstone, and shale Typical profile Ap - 0 to 9 inches: gravelly silt loam E/B- 9 to 14 inches: gravelly silt loam BVE- 14 to 19 inches: gravelly silt loam Bt1 - 19 to 25 inches: gravelly silt loam Bt2-25 to 36 inches: gravelly silt loam C- 36 to 79 inches: gravelly loam Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat): Moderately low to moderately high (0.01 to 1.42 in/hr) Depth to water table: About 18 to 24 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: Moderate (about 7.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e 15 Custom Soil Resource Report Hydrologic Soil Group: B/D Hydric soil rating: No Minor Components Lansing Percent of map unit: 7 percent Landform: Drumlins, hills, till plains Landform position (two-dimensional): Summit, shoulder, backslope Landform position (three-dimensional): Crest, side slope Down-slope shape: Convex Across-slope shape: Convex Hydric soil rating: No Kendaia Percent of map unit: 3 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Appleton Percent of map unit: 2 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Nunda Percent of map unit: 2 percent Landform: Drumlinoid ridges, hills Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Concave Across-slope shape: Convex Hydric soil rating: No Lyons Percent of map unit: 1 percent Landform: Drainageways, depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes 16 Custom Soil Resource Report IcA—Ilion silty clay loam, 0 to 2 percent slopes Map Unit Setting National map unit symbol: 9xmh Elevation: 600 to 1,800 feet Mean annual precipitation: 32 to 42 inches Mean annual air temperature: 45 to 48 degrees F Frost-free period: 120 to 160 days Farmland classification: Farmland of statewide importance Map Unit Composition Ilion and similar soils: 75 percent Minor components: 25 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ilion Setting Landform: Depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Parent material: Loamy till derived from calcareous dark shale Typical profile H1 - 0 to 10 inches: silty clay loam H2- 10 to 26 inches: silty clay loam H3- 26 to 60 inches: silt loam Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Capacity of the most limiting layer to transmit water(Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: About 0 inches Frequency of flooding: None Frequency of ponding: Frequent Calcium carbonate, maximum in profile: 10 percent Available water storage in profile: Moderate (about 7.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4w Hydrologic Soil Group: C/D Hydric soil rating: Yes 17 Custom Soil Resource Report Minor Components Lyons Percent of map unit: 5 percent Landform: Depressions Hydric soil rating: Yes Alden Percent of map unit: 5 percent Landform: Depressions Hydric soil rating: Yes Ovid Percent of map unit: 5 percent Hydric soil rating: No Darien Percent of map unit: 5 percent Hydric soil rating: No Erie Percent of map unit: 5 percent Hydric soil rating: No KnA—Kendaia and Lyons soils, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2trwv Elevation: 430 to 1,510 feet Mean annual precipitation: 31 to 57 inches Mean annual air temperature: 41 to 50 degrees F Frost-free period: 100 to 190 days Farmland classification: Prime farmland if drained Map Unit Composition Kendaia and similar soils: 50 percent Lyons and similar soils: 25 percent Lyons, frequently ponded, and similar soils: 15 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kendaia Setting Landform: Till plains, drumlins, ridges Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Parent material: Calcareous loamy lodgment till derived from limestone, sandstone, and shale 18 Custom Soil Resource Report Typical profile Ap - 0 to 8 inches: silt loam Bw- 8 to 15 inches: silt loam Bg- 15 to 20 inches: gravelly silt loam BCg- 20 to 24 inches: gravelly loam C- 24 to 79 inches: gravelly loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 1.42 in/hr) Depth to water table: About 6 to 18 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: Moderate (about 7.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: B/D Hydric soil rating: No Description of Lyons Setting Landform: Depressions, drainageways Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Parent material: Calcareous loamy lodgment till derived from limestone and shale Typical profile Ap - 0 to 10 inches: silt loam Bg1 - 10 to 19 inches: silt loam Bg2- 19 to 25 inches: silty clay loam BCg- 25 to 34 inches: gravelly silt loam C- 34 to 79 inches: gravelly loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Negligible Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 1.42 in/hr) Depth to water table: About 0 to 6 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: Moderate (about 8.9 inches) 19 Custom Soil Resource Report Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 5w Hydrologic Soil Group: C/D Hydric soil rating: Yes Description of Lyons, Frequently Ponded Setting Landform: Depressions, drainageways Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Parent material: Calcareous loamy lodgment till derived from limestone and shale Typical profile Ap- 0 to 10 inches: mucky silt loam Bg1 - 10 to 19 inches: silt loam Bg2- 19 to 25 inches: silty clay loam BCg- 25 to 34 inches: gravelly silt loam C- 34 to 79 inches: gravelly loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Very poorly drained Runoff class: Negligible Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 1.42 in/hr) Depth to water table: About 0 inches Frequency of flooding: None Frequency of ponding: Frequent Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 5w Hydrologic Soil Group: C/D Hydric soil rating: Yes Minor Components Conesus Percent of map unit: 3 percent Landform: Drumlinoid ridges, hills, till plains Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Concave Across-slope shape: Convex Hydric soil rating: No Lima Percent of map unit: 3 percent Landform: Drumlins, till plains Landform position (two-dimensional): Summit 20 Custom Soil Resource Report Landform position (three-dimensional): Crest Down-slope shape: Concave Across-slope shape: Convex Hydric soil rating: No Ilion Percent of map unit: 2 percent Landform: Depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes Palms Percent of map unit: 2 percent Landform: Swamps, marshes Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Talf Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes LbB—Lansing gravelly silt loam, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 2w3mb Elevation: 460 to 1,800 feet Mean annual precipitation: 31 to 57 inches Mean annual air temperature: 41 to 50 degrees F Frost-free period: 100 to 190 days Farmland classification: All areas are prime farmland Map Unit Composition Lansing and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Lansing Setting Landform: Hills, drumlins, till plains Landform position (two-dimensional): Summit, backslope, shoulder Landform position (three-dimensional): Crest, side slope Down-slope shape: Convex Across-slope shape: Convex Parent material: Calcareous loamy lodgment till derived from limestone, sandstone, and shale 21 Custom Soil Resource Report Typical profile Ap - 0 to 8 inches: gravelly silt loam E- 8 to 13 inches: gravelly silt loam Bt/E- 13 to 21 inches: gravelly silt loam Bt1 -21 to 28 inches: gravelly silt loam Bt2-28 to 39 inches: gravelly silt loam C- 39 to 79 inches: gravelly loam Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat): Moderately low to moderately high (0.01 to 1.42 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: Moderate (about 8.1 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B Hydric soil rating: No Minor Components Conesus Percent of map unit: 8 percent Landform: Drumlins, hills, till plains Landform position (two-dimensional): Summit, shoulder Landform position (three-dimensional): Crest Down-slope shape: Linear Across-slope shape: Convex Hydric soil rating: No Kendaia Percent of map unit: 3 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Appleton Percent of map unit: 2 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No 22 Custom Soil Resource Report Palatine Percent of map unit: 1 percent Landform: Benches, ridges Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest, tread Down-slope shape: Convex Across-slope shape: Convex Hydric soil rating: No Danley Percent of map unit: 1 percent Landform: Drumlinoid ridges, hills, till plains Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest Down-slope shape: Convex Across-slope shape: Convex Hydric soil rating: No Ly—Lyons soils, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2spjy Elevation: 250 to 1,900 feet Mean annual precipitation: 31 to 57 inches Mean annual air temperature: 41 to 50 degrees F Frost-free period: 100 to 190 days Farmland classification: Not prime farmland Map Unit Composition Lyons and similar soils: 75 percent Lyons, frequently ponded, and similar soils: 15 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Lyons Setting Landform: Depressions, drainageways Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Parent material: Calcareous loamy lodgment till derived from limestone and shale Typical profile Ap - 0 to 10 inches: silt loam Bg1 - 10 to 19 inches: silt loam Bg2- 19 to 25 inches: silty clay loam BCg- 25 to 34 inches: gravelly silt loam C- 34 to 79 inches: gravelly loam 23 Custom Soil Resource Report Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Negligible Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 1.42 in/hr) Depth to water table: About 0 to 6 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: Moderate (about 8.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 5w Hydrologic Soil Group: C/D Hydric soil rating: Yes Description of Lyons, Frequently Ponded Setting Landform: Depressions, drainageways Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Parent material: Calcareous loamy lodgment till derived from limestone and shale Typical profile Ap - 0 to 10 inches: mucky silt loam Bg1 - 10 to 19 inches: silt loam Bg2- 19 to 25 inches: silty clay loam BCg- 25 to 34 inches: gravelly silt loam C-34 to 79 inches: gravelly loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Very poorly drained Runoff class: Negligible Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 1.42 in/hr) Depth to water table: About 0 inches Frequency of flooding: None Frequency of ponding: Frequent Calcium carbonate, maximum in profile: 40 percent Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 5w Hydrologic Soil Group: C/D Hydric soil rating: Yes 24 Custom Soil Resource Report Minor Components Appleton Percent of map unit: 3 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Canandaigua Percent of map unit: 3 percent Landform: Depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Tread Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes Kendaia Percent of map unit: 2 percent Landform: Drumlins, till plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No Palms Percent of map unit: 1 percent Landform: Swamps, marshes Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Talf Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes Ilion Percent of map unit: 1 percent Landform: Depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes 25 Custom Soil Resource Report OaA—Ovid silt loam, 0 to 6 percent slopes Map Unit Setting National map unit symbol: 9xnm Elevation: 250 to 1,000 feet Mean annual precipitation: 32 to 42 inches Mean annual air temperature: 45 to 48 degrees F Frost-free period: 120 to 160 days Farmland classification: Prime farmland if drained Map Unit Composition Ovid and similar soils: 75 percent Minor components: 25 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ovid Setting Landform: Till plains, reworked lake plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Parent material: Loamy till with a significant component of reddish shale or reddish glaciolacustrine clays, mixed with limestone and some sandstone Typical profile H1 -0 to 14 inches: silt loam H2- 14 to 24 inches: silty clay loam H3-24 to 60 inches: gravelly loam Properties and qualities Slope: 0 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat poorly drained Capacity of the most limiting layer to transmit water(Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: About 6 to 18 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Available water storage in profile: Moderate (about 8.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C/D Hydric soil rating: No 26 Custom Soil Resource Report Minor Components Lyons Percent of map unit: 5 percent Landform: Depressions Hydric soil rating: Yes Rhinebeck Percent of map unit: 5 percent Hydric soil rating: No Ilion Percent of map unit: 5 percent Landform: Depressions Hydric soil rating: Yes Cayuga Percent of map unit: 5 percent Hydric soil rating: No Kendaia Percent of map unit: 5 percent Hydric soil rating: No 27 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/ nres/detail/national/soils/?cid=nres 142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nres142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/ d eta il/national/landuse/rangepasture/?cid=stelprdb1043084 28 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nres 142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/lnternet/FSE—DOCUMENTS/nrcsl42p2_052290.pdf 29 APPENDIX 4 PRECIPITATION DATA Extreme Precipitation Tables:42.531°N,76.491°W http://precip.eas.comell.edu/data.php?1567449413846 Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series.All precipitation amounts are displayed in inches. Smoothing Yes State New York Location Longitude 76.491 degrees West Latitude 42.531 degrees North Elevation 0 feet Date/Time Mon,02 Sep 2019 14:36:54-0400 Extreme Precipitation Estimates 5min 10min 15min 30min 60min 120min lhr 2hr 3hr 6hr 12hr 24hr 48hr lday 2day 4day 7day 10day lyr 0.28 0.43 0.53 0.70 0.87 1.07 lyr 0.75 0.95 1.21 1.44 1.70 1.99 2.25 lyr 1.76 2.17 2.57 3.10 3.56 lyr 2yr 0.32 0.49 0.62 0.81 1.02 1.26 2yr 0.88 1.12 1.42 1.70 2.00 2.34 2.61 2yr 2.07 2.51 2.94 3.49 4.00 2yr 5yr 0.38 0.59 0.74 0.99 1.26 1.56 Syr 1.09 1.39 1.77 2.11 2.49 2.89 3.23 Syr 2.56 3.11 3.62 4.20 4.80 5yr 10yr 0.42 0.66 0.84 1.14 1.48 1.85 10yr 1.28 1.63 2.10 2.51 2.94 3.40 3.80 10yr 3.01 3.66 4.23 4.84 5.52 10yr 25yr 0.50 0.79 1.00 1.38 1.83 2.30 25yr 1.58 2.02 2.62 3.13 3.66 4.22 4.72 25yr 3.73 4.54 5.21 5.84 6.65 25yr 50yr 0.56 0.90 1.15 1.60 2.15 2.72 50yr 1.86 2.38 3.11 3.71 4.33 4.96 5.56 50yr 4.39 5.34 6.10 1 6.72 1 7.65 1 50yr 100yr 0.63 1.01 1.31 1.86 2.53 3.22 100yr 2.19 2.80 3.69 4.39 5.11 5.84 6.55 100yr 5.17 6.30 7.14 7.75 8.80 100yr 200yr 0.72 1.17 1.51 2.17 2.99 3.81 200yr 2.58 3.30 4.36 5.20 6.03 6.88 7.72 200yr 1 6.09 7.42 8.37 1 8.93 10.14 200yr 500yr 0.85 1.39 1.82 2.64 3.71 4.76 500yr 3.20 1 4.10 1 5.46 6.49 7.52 8.54 9.60 500yr 7.56 9.23 10.33 10.78 12.22 500yr Lower Confidence Limits 5min 10min 15min 30min 60min 120min lhr 2hr 3hr 6hr 12hr 24hr 48hr lday 2day 4day 7day 10day lyr 0.25 0.38 0.47 0.63 0.78 0.81 lyr 0.67 0.80 0.94 1.05 1.50 1.86 2.10 tyr 1.64 2.02 2.43 2.95 3.30 lyr 2yr 0.32 0.49 0.60 0.82 1.01 1.11 2yr 0.87 1.09 1.23 1.52 1.86 2.28 2.54 2yr 2.02 2.45 2.87 3.42 3.92 2yr 5yr 0.36 0.55 0.69 0.94 1.20 1.32 5yr 1.03 1.29 1.44 1.77 2.17 2.71 3.02 5yr 2.40 2.91 3.39 3.98 4.56 5yr 10yr 0.40 0.61 0.76 1.06 1.37 1.50 10yr 1.18 1.47 1.63 1.98 2.45 3.10 3.44 10yr 2.74 3.31 3.85 4.46 5.13 10yr 25yr 1 0.46 0.69 0.86 1 1.23 1 1.62 1.78 1 25yr 1.40 1 1.74 1 1.92 2.29 1 2.85 1 3.67 4.06 1 25yr 3.25 1 3.90 1 4.53 5.19 5.99 25yr 50yr 0.50 0.76 0.95 g1.37l.84 2.04 50yr 1.59 1.99 2.17 2.56 3.21 4.19 4.60 50yr 3.71 4.42 5.13 5.81 6.74 50yr 100yr 0.55 0.84 1.05 08 2.33 100yr 1.80 2.28 2.45 2.86 3.61 4.78 5.22 100yr 4.23 5.02 5.80 6.52 7.58 100yr 200yr 0.62 0.93 1.18 38 2.67 200yr 2.05 2.61 2.79 3.19 4.06 5.45 5.92 200yr 4.82 5.69 6.56 7.30 8:52 200;500yr 0.72 1.07 1.38 85 3.22 SOOyr 2.46 3.15 3.31 3.70 4.75 6.48 6.97 500yr 5.73 6.71 7.71 8.49 9.97 SOOyr Upper Confidence Limits 5min 10min 15min 30min 60min 120min lhr 2hr 3hr 6hr 12hr 24hr 48hr lday 2day 4day 7day 10day lyr 0.30 0.47 0.57 0.77 0.94 1.03 lyr 0.81 1.01 1.16 1.43 1.77 2.12 2.38 lyr 1.88 2.29 2.70 3.25 3.73 lyr 2yr 0.34 0.52 0.64 0.87 1.07 1.18 2yr 0.92 1.15 1.31 1.62 1.98 2.40 2.70 2yr 2.13 2.60 3.03 3.59 4.10 2yr 5yr 0.40 0.62 0.76 1.05 1.33 1.52 5yr 1.15 1.49 1.68 2.06 2.52 3.08 3.45 5yr 2.72 3.31 3.84 4.44 5.07 5yr 10yr 0.46 0.71 0.88 1.23 1.59 1.85 10yr 1.37 1.81 2.03 2.47 3.05 3.72 4.17 10yr 3.29 4.01 4.62 5.24 5.97 lOyr 25yr 0.57 0.86 1.07 1 1.53 2.01 2.41 25yr 1.74 1 2.35 1 2.62 3.15 1 3.93 1 4.78 5.35 25yr 4.23 5.15 5.89 6.53 7.41 25yr 50yr 0.66 1.00 1.25 ..80 2.42 2.92 50yr 2.09 2.86 3.18 3.80 4.76 5.77 6.48 50yr 5.11 6.23 7.10 7.71 8.73 50yr 100yr 0.77 1.16 1.46 2.11 2.89 3.55 100yr 2.49 3.47 3.85 4.59 5.76 6.99 7.85 100yr 6.18 7.55 8.56 9.12 10.28 100yr 200yr 0.90 1.35 1.71 2.48 3.46 4.32 200yr 2.98 4.23 4.67 5.54 6.98 8.45 9.51 200yr 7.48 9.15 10.32 10.77 12.11 200yr 500yr 1.11 1.65 2.13 3.09 4.39 5.59 SOOyr 3.79 5.47 6.02 7.08 9.02 10:89 12.28 SOOyr 1 9.64 1 11.81 1 13.241 13.45 1 15.03 1 SOOyr Po-"ff br r y�l� Northeast Regionhal Chniale Confer 1 of 1 9/2/2019,2:37 PM