SWPPP

DINKS AND LINKS STORM WATER POLLUTION PREVENTION PLAN 912 AND 922 FIVE MILE LINE ROAD

TOWN OF WEBSTER, NEW YORK

Prepared For:

Joe Cattalani 649 Park Avenue Rochester New York 14607

Prepared By:

VANGUARD Engineering PC 133 South Fitzhugh Street Rochester New York 14608 585.427.0320 Vanguard Project Number 202511

April 2026

V:\202511 Dinks and Links SWPPP\reports\SWPPP\SWPPP 202600406.docx

Dinks and Links Storm Water Pollution Prevention Plan

4/2026

TABLE OF CONTENTS I.

Project Information ........................................................................................................................ 1

II

Site Planning and Practice Selection ............................................................................................. 2

III.

Erosion, Sediment & Stabilization Practices ................................................................................ 4

IV.

Good Housekeeping ........................................................................................................................ 7

APPENDICES Appendix A:

NYSDEC Notice-of-Intent NYSDEC Acknowledgement MS4 Acceptance NYSDEC Notice-of-Termination

Appendix B:

Site Location Map

Appendix C:

Marathon Engineering Wetlands Delineation Map

Appendix D:

FEMA Flood Insurance Rate Map

Appendix E:

NRCS Web Soil Survey Map and Information

Appendix F:

Runoff Reduction Volume (RRv) Calculations

Appendix G:

Pre-construction Conditions Calculations

Appendix H:

Post-construction Conditions Calculations

Appendix I:

Future Conditions Calculations

Appendix J:

Rainfall Frequency/Depth Data

Appendix K:

Channel Protection Volume (CPv) Calculations

Appendix L:

Grading and Erosion Control Plan

Certifications

Appendix O:

Inspection Reports

Appendix P:

Long Term Maintenance Plan I

Dinks and Links Storm Water Pollution Prevention Plan

I.

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Project Information 1. Project Name:

Dinks and Links

2. Project Engineer and Firm:

Joseph Ardieta PE, Vanguard Engineering PC

3. Project location: 1. Municipality 2. Tax parcel # 3. Nearest cross street distance 4. Watershed

Town of Webster, New York 079.10-1-1.11 and -2.3 ~0.4 miles west of access road intersection with Hard Road Shipbuilders Creek

4. Applicant name and address:

Joe Cattalani 649 Park Avenue Rochester New York 14607

5. Purpose: This Storm Water Pollution Prevention Plan (SWPPP) was created to comply with the New York State Department of Environmental Conservation (NYSDEC) State Pollutant Discharge Elimination System (SPDES) General Permit for Storm Water Discharges Associated with Construction Activities (GP-0-25001; found at http://www.dec.ny.gov/chemical/43133.html) and the local municipality’s storm water management objectives. This document reports existing and proposed site conditions, explains storm water management during and after the construction period, details soil disturbance and stabilization practices and certifies who will be responsible for implementing and maintaining those practices. The project provides required SWPPP documentation, consisting of the NYSDEC Notice-of-Intent (NOI), NYSDEC Acknowledgement and, once applicable, the NYSDEC Notice-of-Termination (NOT) in Appendix A. 6. Methodology: We utilized the 2024 version of the Storm Water Management Design Manual (SMDM2024) for computing storm water requirements and used its design standards for meeting those requirements. This report analyzed the project hydrologic system using the computer program HydroCAD version 10.20, based upon the US Soil Conservation Service’s TR-20 and TR-55 hydrologic methodology, to create computer models representing the pre- and post-developed site conditions. The program runs theoretical storm scenarios through the models and computes runoff with relation to time. 7. Project Description: The proposed construction project is located predominantly on the south side of an access road that runs between Five Mile Line and Hard Roads, and is east adjacent to the current Lowe’s Home Improvement store. See Appendix B for Site Location Map. The surrounding area contains commercial and vacant commercial land. The proposed project is to construct an indoor/outdoor recreational facility on an undeveloped commercial parcel. It will consist of an approximate 38,400 square-foot building along with outdoor pavilions and recreational pits. Also, the project will add a 293-space parking lot. The total lot area contains 22.28 acres. Proposed project disturbance is 5.8 acres. However, construction will be phased to maintain less than 5 acres of disturbance at all times. The project will propose several storm water management practices (SMPs) that will convey to three existing detention ponds constructed circa 2003 as part of the overall commercial subdivision. 8. Wetlands and Floodplain: Marathon Engineering performed a wetland delineation of the site in 2022. However, Diehlux is currently coordinating updated wetland boundaries with NYSDEC and a permit is forthcoming. See Appendix C for Marathon 2022 wetland delineation map. The current drawing set delineates the forthcoming permit boundaries. The Federal Emergency Management Agency’s (FEMA) Flood Insurance Study for Monroe

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County with Map Number 36055C 229G dated August 28, 2008 indicates no regulated floodplain within project limits. (Appendix D). 9. Site Soils: The study area contains predominantly Alton gravelly sandy loam with some Claverack loamy fine sand and Massena fine sandy loam soils. Alton is rated Hydrologic Soil Group (HSG) A whereas Claverack and Massena are rated C/D. HSG A soils exhibit good rates of water infiltration and sub grade transportation. HSG C/D soils exhibit less than moderate rates of water infiltration and sub grade transmission when drained and perform poorly when not drained. We model dual-classified soil as D as a conservative measure. See Appendix E for detailed site soils information. 10. Site Archeology: NYSDEC requires projects to make certain accommodations to historically or archeologically significant structures or objects. New York State Historic Preservation Office (SHPO) has no jurisdiction on the site since it was previously approved for construction, cleared, graded and partially developed. Therefore, no further action is required regarding archeology.

II Site Planning and Practice Selection This SWPPP utilizes the NYSDEC site planning process to reduce for storm water management practice (SMP) selection. The incremental process indicates selected practices and quantifies their storm water management value. 1. Natural Features Preservation Natural Resource Preservation Practices a. Undisturbed Area Preservation: This practice allocates specified lands to be left in their natural condition with a legal document, such as a deed covenant, to ensure it remains undeveloped. In this case, the operator does not wish to be encumbered by deed restrictions. b. Buffer Preservation: This practice restricts development near perennial streams, rivers, shorelines or wetlands. In this case, the operator does not wish to be encumbered by deed restrictions. c. Clearing and Grading Reduction: This project will limit clearing and grading to developed areas only. d. Locating Development in Less Sensitive Areas: This project will not impact floodplain, steep slopes, erodible soils or critical habitats. There will be a slight impact to wetlands. e. Open Space Design: This project is not applicable to open space design. f. Soil Restoration: Pervious areas shall remain in their natural condition with grass vegetation cover. Contractor shall restore all disturbed areas in accordance with Table 5.2 (SMDM2024, page 5-12). Impervious Cover Reduction Practices a. Roadway Reduction: This site design does not propose to add a roadway. b. Sidewalk Reduction: This design proposes minimal sidewalks. c. Driveway Reduction: Driveways are proposed to parking lots, but the lengths are minimal. d. Cul-de-Sac Reduction: The project does not propose cul-de-sacs. e. Building Footprint Reduction: This project cannot feasibly reduce the building area. f. Parking Reduction: This project proposes enough parking to meet the anticipated demand. Green Infrastructure Techniques a. Conservation of Natural Areas: Due to legal restrictions required for Conservation of Natural Areas, the applicant does not wish to encumber the property. b. Sheet Flow to Riparian Buffers or Filter Strips: There are no perennial streams within the proposed work limit area. Therefore, this technique is not available for this project. c. Tree Planting/Tree Pits: This project does not propose to plant a substantial number of trees. d. Rooftop Runoff Disconnection: The proposed building is too close to outdoor facilities to feasibly utilize rooftop disconnection.

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e. f. g. h. i. j.

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2. Site Water Quality Volume (WQv) Calculation NYSDEC requires a project’s storm water management system must treat at least 25% of the Water Quality Volume (WQv) within redeveloped areas and 100% of WQv in newly developed portions. This project will only employ new development for WQv calculations. It encompasses only the disturbed portion of the project, not the entire site. It also does not include the access road or adjacent Lowes pavement since these surfaces are existing. As a result, the total area and percent impervious for this calculation is different from the site as a whole. The standard Water Quality Volume (WQv) is computed using the “90% Rainfall Rule”: WQv = (P)*(Rv)*(A)/12*0.25 (redeveloped areas) + (P)*(Rv)*(A)/12 (previously undeveloped areas). For this project, 3.61 acres of impervious surface was applied to new construction. Whereas; P = 90% Rainfall Event Number = 1.00 inch within Monroe County, I = percentage of impervious surface = 39%, Rv = Runoff Coefficient = 0.05 + 0.009(I) (0.2 minimum) = 0.40, and A = site area = 9.32 acres. WQv = Water Quality Volume = 13,485 cubic-feet (0.31 acre-feet). 3. Runoff Reduction Volume (RRv) Calculation Using Green Infrastructure and Standard SMPs NYSDEC calls for targeting RRv equaling 100% of the WQv for newly developed areas. In the event a project cannot meet this criterion, the NYSDEC established a minimum RRv requirement equation: Minimum Allowable RRv = .95(P)*(S)*(Ai)/12; Whereas, P = 90% Rainfall Event Number = 1.00 inch, S = Soil HSG Reduction Factor = 0.55 (A soils), 0.40 (B), 0.30 (C), 0.20 (D). This project contains A (6.70 acres) and D (2.62 acres) soils within the disturbed area. Therefore, the calculated S = 0.45, and Ai = Impervious Area within watershed (including existing and new development) = 3.61 acres. Minimum Allowable RRv = 5,619 cubic-feet (0.13 acre-feet). The following Green Infrastructure techniques are proposed for this project. See Appendix F for detailed RRv calculations. a. Infiltration Trenches This technique is proposed to service the proposed loop road on the northern portion of the site. One will run alongside the west edge of the road and the other will run alongside the southern edge. RRv = 1,396 cubic-feet (0.03 acre-feet), b. Infiltrating Bioretention One bioretention facility will be located south of the proposed parking lot. It will take runoff from the parking lot and building roof via storm sewer network. The sewer will discharge to a plunge pool pretreatment device. The bioretention facility will discharge to the existing South Pond. Bioretention practices provide 100% RRv reduction. The proposed facility will be within HSG A soil regime. Infiltration testing conducted on July 15, 2025 revealed a 6 inch per hour infiltration rate. The bioretention facility will provide RRv = 7,147 cubic-feet (0.16 acre-feet). 3

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c. Dry Swale This technique is proposed to service the predominantly pervious eastern portion of the site. One will run alongside the southern edge of the road and the other will capture runoff from the eastern portion of the site. RRv = 211 cubic-feet (0.005 acre-feet), 4. Water Quality Volume Balance The total RRv reduced by Green Infrastructure practices = 8,754 cubic-feet (0.20 acre-feet) which exceeds the minimum allowable RRv, but does not meet the WQv. The balance of the WQv will be treated by the dry swales and the proposed Micropool Extended Detention Pond replacing the Center Pond. They will provide an additional WQv = 4,731 cubic-feet (0.11 acre-feet.) The composite of RRv and WQv practices = 13,485 cubic-feet (0.31 acre-feet), meeting the required WQv. Although we did not include in our calculations here, additional WQv will be accommodated within the three existing ponds. 5. Volume and Peak Rate Control Practices a. Analyzed Area Description The lot is comprised of a 14.34-acre parcel area. There is also a 4.5-acre off-site area east of the lot that flows onto the lot. An access road bisects the lot along an east-west axis. Runoff generally flows to the northwest on the northern portion and south on the southern portion of the lot. Slopes are mild throughout the site. The work limit area’s ground condition is predominantly range on the northern portion and woods on the southern portion. Two ponds; designated North and Center Ponds are located in the northern portion of the site and the South Pond in the southern portion. The off-site areas are comprised of woods and the aforementioned access road. Previous Studies We attempted to retrieve the original Drainage Report for the subdivision (Costich Engineering, dated 2002), but only received a portion of the study which did not include calculations of the project’s parcel or the South Pond currently located at the southern boundary of the project site. As a result, we were unable to confirm the calculations which determined the south pond’s sizing. Thus, we do not include the off-site contribution to the south pond since the data is unavailable and cannot confirm the pond is properly sized. We received a SWPPP (Costich Engineering, dated 2006) subsequent to the original drainage study that included the northern portion of the project site. This SWPPP created the North and Center ponds. We include that SWPPP’s calculations, updated their model to today’s storm hydrographs and then compared it against this project’s projected peak discharges. Pre-construction Drainage Conditions Model For modeling purposes, the analyzed area was divided into five subcatchments. 1S represents flow to the northern area, 2S represents flow to the center area, 3S represents flow to the South Pond, 4S is offsite flow to the northern area and 5S is off-site flow to the center area. Node 1L represents the composite drainage that flows through the site. There are three on-site ponds constructed as part of the overall subdivision storm water management network. We did not include these existing ponds in the preconstruction model because to do so would artificially reduce the peak flows vis-à-vis the conditions that were present when the subdivision was created in 2002. Our model utilizes the site’s current surface conditions since we do not know the surface conditions when the original subdivision was created. Table 1 shows the peak discharges of the 2006 Costich SWPPP on the northern portion of the site, the same figures updated to today’s storm event standard and this SWPPP’s analysis of current conditions. See Appendix G for the adjusted 2006 Costich analysis and our detailed pre-construction conditions analysis. Post-construction Drainage Conditions Model The analyzed area was divided into the same six subcatchments. 1S represents flow to the North Pond, 1AS represents flow to the infiltration trenches, 2S represents flow to the Center Pond, 3S represents

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flow to the Bioretention facility (and subsequently the South Pond), 4S is flow directly to the South Pond, 5S is off-site flow to the Northern Pond and 6S is off-site flow to the Center Pond. Pond 1 represents the infiltration trenches. Pond 2 is the bioretention facility (2A is the pre-treatment plunge pool.) Ponds 3 through 5 represent the existing North, the Replaced Center and South Ponds, respectively. The Pond’s volume are based on the project’s proposed topography. Node 1L represents the composite site drainage. See Appendix H for the detailed post-construction conditions calculations. Climate Consideration Consideration was taken with respect to the changing climate. For this project, we increased the precipitation figures by 15% in the post-construction model to account for anticipated future increase in storm rainfall volumes. The purpose is to design SMPs now that will remain functional in the foreseeable future. Note the highlighted peak elevations compared with the flood elevation of the proposed SMPs. See Appendix I for the future conditions model. See Appendix J for current and projected future storm event rainfall depth figures. b. Channel Protection NYSDEC’s Channel Protection Volume (CPv) criterion requires projects to detain the 1-year storm event runoff volume for 24 hours. The required CPv for this project is 3,553 cubic-feet (0.082 acrefeet). During the 1-year storm event, the results indicate; all inflow to the North Pond routs through the 3” orifice (0.106 acre-feet), the Infiltration Trenches fully infiltrates 0.031 acre-feet and the Bioretention facility fully infiltrates 0.240 acre-feet. All other SMPs do not count toward CPv. The total provided CPv = 16,422 cubic-feet (0.38 acre-feet). See Appendix K for details. c. Overbank Flood and Extreme Flood. Results are based upon a single 24-hour storm event with data provided by the Northeast Regional Climate Center for the Town of Webster. Antecedent Moisture Condition was set at 2, representing moderate conditions. We used the Dynamic Storage-Indication method for pond routing. The 10- and 100-year storm event rainfall depths, taken from Appendix J, were 3.08 and 5.16 inches, respectively, for the pre- and post-development conditions models and 3.54 and 5.93 inches for the future conditions model. Computations indicate peak discharges will reduce from the pre- to the post-construction conditions as well as from the 2006 Costich figures for the northern portion of the site. See Table 1 for resultant figures. See Appendix H for detailed pre-construction and Appendix I for post-construction detailed calculations.

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Dinks and Links Storm Water Pollution Prevention Plan

Peak Discharge

Storm Event

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10-year

100-year

2006 Costich Northern Portion Peak Discharge (cfs)

2006 Costich Northern Portion Adjusted Peak Discharge (cfs)

Site Preconstr. Peak Discharge (cfs)

Site Postconstr. Peak Discharge (cfs)

2006 Costich Northern Portion Peak Discharge (cfs)

2006 Costich Northern Portion Adjusted Peak Discharge (cfs)

Site Preconstr Peak Discharge (cfs)

Site Postconstr Peak Discharge (cfs)

8.34

6.26

2.46

0.74

15.66

18.30

10.24

9.95

Table 1 Pre- and Post-construction Peak Discharge Comparison

III. Erosion, Sediment & Stabilization Practices A. Project Practice Description: Contractor shall provide erosion and sediment control according to the Grading and Erosion Control Plan and detail sheet provided in Appendix L. Contractor shall install and maintain all devices and follow procedures as required in the publication New York State Standards and Specifications for Erosion and Sediment Controls, latest revision. The project contractor shall adhere to the construction sequence enumerated in Appendix M. Certifications regarding this Storm Water Pollution Prevention Plan are required by the project developer and the major contractors associated with the project. Certification forms are in Appendix N. Install silt fence along the work limit area perimeter wherever runoff will exit the work area or as ordered by engineer. Place silt fence on a consistent contour where allowable to avoid concentrating runoff along the fence. The device type may change with the surrounding surface. For instance, staked silt fence applies when surrounding grade is earth, but does not work on paved surfaces. Devices such as block and stone or coir logs are better suited for hard surfaces. Temporary stone check dams will be installed within concentrated flow channels as shown on site drawings and as ordered by Engineer or governing local authority representative. Topsoil stock piles and disturbed portions of the site where construction activity temporarily ceases for at least 7 days will be stabilized with temporary seed and mulch no later than 7 days from the last construction activity in that area. The temporary seed shall be annual rye applied at the rate of 40 lbs. per acre. After seeding, each area shall be mulched with 2 tons per acre or 3 bales of straw per 1000 square feet. The straw mulch is to be tacked into place by a disk with blades set nearly straight. Areas of the site that are to be paved will be temporarily stabilized by applying geotextile and stone sub-base until bituminous pavement can be applied. Lime and fertilizer will be applied as determined by soil tests. The permanent seed mix shall meet site drawing specifications. After seeding, each area shall be mulched as described above. All slopes greater than 3H:1V shall have jute mesh or other engineer approved stabilization fabric applied. Contractor shall construct a stabilized construction entrance from the access road to reduce vehicle tracking of sediment. Public roads shall be swept to remove any excess mud, dirt or rock tracked from the site. The

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street shall also be swept immediately if ordered by Engineer or governing local authority representative. Dump trucks hauling material from the construction site will be covered with a tarpaulin. Diversions, stabilized construction entrances and sediment basins will be constructed prior to mass earthwork. Once construction activity ceases permanently, the area will be stabilized with permanent seed and mulch. After site stabilization, the accumulated sediment will be removed from the sediment basin. B. Other practices to be installed: None are specified at this time. C. Maintenance and Inspection Procedures: The contractor and applicant shall use the following inspection and maintenance practices to maintain erosion and sediment controls during construction: • Inspect all control measures at least once each week (twice per week if disturbance exceeds 5 acres at any time). • Maintain all measures in good working order; initiate any necessary repair within 24 hours of report. • Remove built-up sediment along silt fence when it has reached one-third the height of the fence. • Inspect silt fence for depth of sediment, tears, to see if the fabric is securely attached to the fence posts, and to see that the fence posts are firmly staked. • Inspect sediment basin for depth of sediment and remove built-up sediment when it reaches the previously stated level. • Inspect temporary and permanent seeding and planting for bare spots and washouts. Replace as necessary. • Complete a maintenance and inspection report immediately after each inspection. Use the NYSDEC standard checklist supplied in Appendix O to assist. Attach a record of all reports to Appendix O. The developer will select an inspection firm who will be responsible for inspections and completing reports. The site superintendent will select individual(s) responsible for additional inspections, maintenance and repair activities. Personnel selected for inspection and maintenance responsibilities must be trained in all inspection and maintenance practices necessary to keep the practices in good working order. Once construction is completed, the owner/operator will be responsible for the proper operation and maintenance of the proposed SMPs. A long-term maintenance agreement with the municipality is provided in Appendix P. The applicant shall maintain a copy of the NOI, NOI Acknowledgment Letter, SWPPP, MS4 SWPPP Acceptance form and inspection reports at the construction site until all disturbed areas achieve final stabilization and the NOT is submitted to NYSDEC. The applicant must maintain documents in a secure location, such as a job trailer, on-site construction office, or mailbox with lock. The secure location must be accessible during normal business hours to an individual performing a compliance inspection.

IV.

Good Housekeeping

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• Products will be kept in original containers unless they are not re-sealable. • Original labels and material safety data sheets will be retained; they contain important product information. • Store only enough product required to complete the job on-site. • All materials stored on-site will be in a neat, orderly manner in their appropriate containers and, if possible, under roof or other enclosure and/or on blacktop. • Products will be kept in their original containers with original manufacturer’s label. • Substances will not be mixed unless recommended by the manufacturer. • Whenever possible, all of a product will be used up before disposing of the container. • Manufacturer’s recommendations for proper use and disposal will be followed. • The site superintendent will inspect daily to ensure proper use and disposal of materials on-site. C. Spill Control Practices: In addition to the good housekeeping and material management practices discussed in the previous sections of this plan, the following practices will be followed for spill prevention and cleanup: • Manufacturers’ recommended methods for spill cleanup will be clearly posted and site personnel will be made aware of the procedures and the location of the information and cleanup supplies. • Materials and equipment necessary for spill cleanup will be kept in the material storage area on-site. Equipment and materials will include but not be limited to brooms, dust pans, mops, rags, gloves, goggles, kitty litter, sand, sawdust, and plastic and metal trash containers specifically for this purpose. • All spills will be cleaned up immediately after discovery. • The spill area will be kept well-ventilated and personnel will wear appropriate protective clothing to prevent injury from contact with a hazardous substance. • Report any toxic or hazardous material spills to the appropriate State or local government agency. • The spill prevention plan will be adjusted to include measures to prevent recurrence and how to clean up the spill if there is another one. A description of the spill, what caused it, and the cleanup measures will also be included. The site superintendent responsible for the day-to-day site operation will be the spill prevention and cleanup coordinator. The superintendent will designate at least three other site personnel who will receive spill prevention and cleanup training. These individuals will each become responsible for a particular phase of prevention and cleanup. The names of responsible spill personnel will be posted in the material storage area and in the office trailer on-site. D. Product Specific Practices: The following product specific practices will be followed on-site: • Petroleum Products - All on-site vehicles will be monitored for leaks and receive regular preventive maintenance to reduce the chance of leakage. Petroleum products will be stored in tightly sealed containers that are clearly labeled. Any asphalt substances used on-site will be applied according to the manufacturer’s recommendations. • Fertilizers - Fertilizers used will be applied only in the minimum amounts recommended by the manufacturer and as described in part IV (A). Once applied, fertilizer will be worked into the soil to limit exposure to storm water. Storage will be in a covered shed. The contents of any partially used bags of fertilizer will be transferred to a sealable plastic bin to avoid spills. • Paints - All containers will be tightly sealed and stored when not required for use. Excess paint will not be discharged to the storm sewer system but will be properly disposed according to manufacturers’ instructions or state and local regulations. • Concrete Trucks - Concrete trucks shall wash out or discharge surplus concrete or drum wash water only at area designated on Grading and Erosion and Sediment Control Plan. • Waste Disposal - All waste materials will be collected and stored in a securely lidded metal dumpster rented from a NYS-licensed solid waste management company. The dumpster will meet all local and 8

Dinks and Links Storm Water Pollution Prevention Plan

•

• • •

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any State solid waste management regulations. All trash and construction debris from the site will be deposited in the dumpster. The dumpster will be emptied a minimum of twice per week or more often if necessary. No construction waste materials will be buried on-site. All personnel will be instructed regarding the correct procedure for waste disposal. Notices stating these practices will be posted in the office trailer. The site superintendent or individual managing the day-to-day site operations will be responsible for seeing that these procedures are followed. Hazardous Waste - All hazardous waste materials will be disposed of in the manner specified by local or State regulation or by the manufacturer. Site personnel will be instructed in these practices. The site superintendent or individual managing the day-to-day site operations will be responsible for seeing that these procedures are followed. Sanitary Waste - All sanitary waste will be collected from the portable units a minimum of three times per week by a licensed sanitary waste management contractor, as required by local regulation. Recyclable Waste – All recyclable waste (cardboard, wood etc.) shall be collected and recycled. Copper Sulfate – Copper Sulfate, an algaecide used in water bodies, may not be used at any location within the project site due to its toxicological effects.

9

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SWPPP Preparer Certification Form SPDES General Permit for Stormwater Discharges from Construction Activity, GP-0-25-001 (CGP) (In accordance with CGP Part I.D.2.b., the completed form must be attached to the eNOI and submitted to NYSDEC electronically.)

Project/Site Name:

Dinks and Links

eNOI Submission ID: Owner/Operator Name:

Joe Cattalani

Joseph

C

Ardieta

SWPPP Preparer First Name

MI

SWPPP Preparer Last Name

4/06/2026 Signature

Date

Publi sh ers P k w y

y Ln

Abiga

y le

Way

Ha r d Rd

as

rr be

site

Front a

18

Fr on t a ge Rd

ut e 104 104

Ca r d il e D

Front

e 104 S ta t e R o u t

F r o nt ag e Rd

ge Rd

age Rd

r 18

DMV

Webster Square 18

B

Win if r e d Dr

7/15/2025, 4:59:03 PM

Parcels

ge

Webster Town Hall

Ridg

e Rd

ck

H armony Sta

404

Five Mile Line Rd

R i d ge R d

Rid

la

Ri dge Rd

C he r ry B lvd

G

ArcGIS Web Map

N e w be r r y L n

Rd

Webster Schroeder High School

1:14,191 0

0.07

0.15

0.3 mi

0

0.13

0.25

0.5 km

Esri Community Maps Contributors, Monroe County GIS, Esri, TomTom, Garmin, SafeGraph, GeoTechnologies, Inc, METI/NASA, USGS, EPA, NPS,

Field Team found no wetlands or watercourses during site visit in this area of review.

Wetland delineation completed by DIEHLUX on 10/24/2022 & 10/25/2022 using Trimble R1 GPS Units. ALL wetland flagging ( W1-1 to W1-220, W2-1 +E to W2-18+E, W3-1 to W3-17, W4-1 +E to W4-12 +E, ST1-1 +W to ST1-25+S, ST1-2x, and ST1-2y, WB1-1 to WB1-16, WB2-1 to WB2-7, WB3-1 to WB3-12, WB4-1 to WB4-16, DT1-1 to DT1-7, and DT2-1 to DT2-6) are glo-pink with "WETLAND DELINATION" markings. Map produced for survey support purposes only and is NOT TO SCALE.

National Flood Hazard Layer FIRMette

Legend

77°28'37"W 43°12'55"N

SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT

Without Base Flood Elevation (BFE) Zone A, V, A99

With BFE or Depth Zone AE, AO, AH, VE, AR

SPECIAL FLOOD HAZARD AREAS

Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Zone X Future Conditions 1% Annual Chance Flood Hazard Zone X Area with Reduced Flood Risk due to Levee. See Notes. Zone X Area with Flood Risk due to Levee Zone D

OTHER AREAS OF FLOOD HAZARD NO SCREEN

Area of Minimal Flood Hazard

Zone X

Effective LOMRs

OTHER AREAS

Area of Undetermined Flood Hazard Zone D

GENERAL STRUCTURES

Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall

B

8

OTHER FEATURES

20.2 17.5

Cross Sections with 1% Annual Chance Water Surface Elevation Coastal Transect Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary Coastal Transect Baseline Profile Baseline Hydrographic Feature Digital Data Available No Digital Data Available

MAP PANELS

Unmapped

Ü

The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 7/13/2025 at 12:16 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time.

0

250

500

1,000

1,500

Feet 2,000

1:6,000

77°27'59"W 43°12'29"N

This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes.

299270

299320

299370

299420

299470

299520

299570

77° 27' 54'' W

299620

299670

299720

299770

43° 12' 48'' N

4787180

4787180

4787230

4787230

4787280

4787280

4787330

4787330

4787380

4787380

4787430

4787430

4787480

43° 12' 48'' N

4787480

77° 28' 16'' W

Hydrologic Soil Group—Monroe County, New York

Soil Map may not be valid at this scale.

43° 12' 38'' N

43° 12' 38'' N

299320

299370

299420

299470

299520

N

Meters 180 Feet 0 100 200 400 600 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0

30

Natural Resources Conservation Service

60

120

Web Soil Survey National Cooperative Soil Survey

299570

299620

299670

299720 77° 27' 54'' W

77° 28' 16'' W

299270

3/17/2026 Page 1 of 4

Hydrologic Soil Group—Monroe County, New York

MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A

MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:15,800.

C C/D D

Not rated or not available

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography

A/D B

Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

B/D

C C/D

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

D

Date(s) aerial images were photographed: 28, 2023

Not rated or not available Soil Rating Points

May 15, 2023—May

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.

A A/D B B/D

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/17/2026 Page 2 of 4

Hydrologic Soil Group—Monroe County, New York

Hydrologic Soil Group

Map unit symbol

Map unit name

Rating

Acres in AOI

Percent of AOI

AnA

Alton gravelly sandy loam, 0 to 3 percent slopes

A

8.2

65.2%

CkB

Claverack loamy fine sand, 2 to 6 percent slopes

C/D

3.5

27.6%

Mf

Massena fine sandy loam

C/D

0.9

7.2%

12.5

100.0%

Totals for Area of Interest

Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/17/2026 Page 3 of 4

Hydrologic Soil Group—Monroe County, New York

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/17/2026 Page 4 of 4

AY IRONDEQUOIT WAYNE COUNTY EXPRESSW (NEW YORK ROUTE 104) (R.O.W. VARIES)

398 401 2+00

1+00

0+00

3+ 00

400

5+00

400

400

4+00

401

INFILTRATION TRENCH

398

6+00

402

401

7+00

40

401

402

397

REVISED CENTER POND

2 7+26.68

2 40

404 404

404

404

403

403

404

405

405

404

405 40

INFILTRATING BIORETENTION

405

40

404

2

3

403

5 40

WET SWALE

403

401.9

400.5

399.0 X

PLUNGE POOL (10' x 216')

X 399.0

X 401.7

X 400.5 X

X 401.5 X

400.5 X

406 401.5 X

401

BLACK CHERRY BLVD (70' R.O.W.)

401

INFILTRATING BIORETENTION (36' x 205')

10' WIDE BROAD-CRESTED WEIR AT EL=401.50

X

405

402 401.9 X 401.7

GREEN INFRASTRUCTURE BOUNDARY MAP

NOI QUESTIONS

#

eNOI Question 49

Reported Value cf

af

49

Total Water Quality Volume (WQv) Required

13485

0.310

49

Total RRV Provided

8754

0.201

49

Is RRv Provided ≥WQv Required?

49

Minimum RRv

49

Is RRv Provided ≥ Minimum RRv Required?

49

Total WQv Treated

845

0.019

4,731

49

Sum of Volume Reduced & Treated

9599

0.220

13,485 0.310

49

Is Sum RRv Provided and WQv Provided ≥WQv Required?

No 5619

0.129 Yes

No

Yes

The GI Worksheets contain a programming error for Micropool Extended Detention ponds. The base required area for such ponds is 10 acres. However, that figure may be reduced to 5 acres if the pond meets or exceeds the calculated Water Balance figure, which this pond does. The worksheet indicates 0 cubic-feet Water Quality Volume whereas it actually provides 3,886 cubic-feet. The corrections above and on other sheets corrects the GI Worksheet error.

0.109

Step 1 - Site Planning Practice

Description

Preservation of Natural Features and Conservation Design

Delineate and protect Preservation undisturbed forests, native of Undisturbed vegetated areas, riparian corridors, water bodies, Areas wetlands, and natural terrain.

Applicable

No

Preservation of Buffers

Delineate and protect naturally vegetated buffers along perennial streams, rivers, shorelines, and wetlands.

No

Reduction of Clearing and Grading

Limit clearing and grading to the minimum amount needed for roads, driveways, foundations, utilities and stormwater management facilities.

Yes

Locating Development in Less Sensitive Areas

Avoid sensitive resource areas such as floodplains, steep slopes, erodible soils, wetlands, mature forests and critical habitats by locating development to fit the terrain in areas that will create the least impact.

Open Space Design

Use clustering, conservation design or open space design to reduce impervious cover, preserve more open space and protect water resources.

Soil Restoration

Restore the original properties and porosity of the soil by deep till and amendment with compost to reduce the generation of runoff and enhance the runoff reduction performance of post construction practices.

Yes

N/A

Yes

Step 1 - Site Planning

Roadway Reduction

Reduction of Impervious Cover

Sidewalk Reduction

Driveway Reduction

Cul-de-sac Reduction

Building Footprint Reduction

Parking Reduction

Minimize roadway widths and lengths, below local requirements, to reduce site impervious area

Minimize sidewalk lengths and widths, below local requirements, to reduce site impervious area

Minimize driveway lengths and widths, below local requirements, to reduce site impervious area

Minimize the number of cul-desacs and incorporate landscaped areas to reduce their impervious cover. Reduce the impervious footprint of residences and commercial buildings by using alternate or taller buildings while maintaining the same floor to area ratio. Reduce imperviousness on parking lots by eliminating unneeded spaces, providing compact car spaces and efficient parking lanes, reducing stall dimensions below local requirements, using porous pavement surfaces in overflow parking areas, and using multistoried parking decks where appropriate.

No

Yes

N/A

N/A

No

No

Step 2 - Calculate Water Quality Volume Is this project subject to Section 4.3 of the NYS Design Manual for Enhanced Phosphorus No Removal? What is the nature of this construction project? New Construction Design Point: Enter 90% Rainfall Event as P P= 1.00 inches Calculate Required WQv Drainage Area Number

Contributing Impervious Area Area (Acres) (Acres)

Percent Impervious %

Rv

WQv (cf)

1

0.49

0.40

82

0.78

1,396

2

2.48

2.05

83

0.79

7,147

3

3.12

0.15

5

0.09

1,056

SMP Description Infiltration Trench Infiltration Bioretention Wet Swale

4

3.23

1.01

31

0.33

3,886

Micropool Extended Detention 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

9.32

3.61

39

0.40

13485

Required WQv

Steps 3 and 5 - Apply RR Techniques and Standard SMPs Runoff Reduction Volume and Treated Volumes Total Total Contributing Contributing Impervious Area Area

Alt. SMPs

Standard SMPs

Standard SMPs w/ RRv Capacity

RR Techniques

Runoff Reduction Techiques/Standard SMPs

Conservation of Natural Areas RR-1 Sheet Flow to Riparian Buffer/Filter Strip RR-2 Tree Planting/Tree Pit/Tree Trench RR-3 Disconnection of Rooftop Runoff RR-4 Vegetated Swale RR-5 Rain Garden RR-6 Stormwater Planter RR-7 Rainwater Harvesting Systems RR-8 Porous Pavement RR-9 Green Roof (Extensive & Intensive) RR-10 Stream Daylighting RR-11 Infiltration Trench I-1 Infiltration Basin I-2 Dry Well I-3 Underground Infiltration System I-4 Infiltration Bioretention F-4 Filtration Bioretention F-5 Bioslope F-6 Dry swale O-1 Micropool Extended Detention P-1 Wet Pond P-2 Wet Extended Detention P-3 Multiple Pond System P-4 Shallow Wetland W-1 Extended Detention Shallow Wetland W-2 Pond/Wetland System W-3 Pocket Wetland W-4 Gravel Wetland W-5 Surface Sand Filter F-1 Underground Sand Filter F-2 Perimeter Sand Filter F-3 Wet Swale O-2

(acres) 0.49 0.00 0.00

(acres)

WQv Reduced (RRv)

WQv Treated

(cf) 0 0 0 0 0 0 0 0 0 0

(cf)

1,396 0 0 0 7,147 0 0 211

0 0 0 0 0 0 0 845 0 3,886 0 0 0 0 0 0 0 0 0 0 0 0

0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.49 0.00 0.00 0.00 2.48 0.00 0.00 3.12 3.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.40 0.00 0.00 0.00 2.05 0.00 0.00 0.15 1.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00

0.00

Totals by RR Technique →

0.49

0.00

0

Totals by Standard SMP w/RRV →

6.09

2.60

8,754

Totals by Standard SMP →

3.23

1.01

0

Totals by Alternative SMP →

0.00

0.00

0

Totals ( RR Techniques + all SMPs) →

9.81

3.61

Flow Based Alternative Practice

-

Volume Based Alternative Practice

-

0

8,754

8454,731

8454,731

RR Techniques

Step 3 - Evaluation of RR Techniques and Standard SMPs with RRv Capacity Practice

Description

Conservation of Natural Areas (RR-1)

Retain the pre-development hydrologic and water quality characteristics of undisturbed natural areas by permanently conserving these areas on a site. Undisturbed natural areas include: forest retention areas; reforestation areas; stream and river corridors; shorelines; wetlands, vernal pools, and associated vegetated buffers; and undisturbed open space.

Applicable Project Specific Evaluation

No

Undisturbed natural areas such as forested conservation areas Sheet Flow to and stream buffers or vegetated Riparian filter strips and riparian buffers Buffer/Filter can be used to treat and control Strip (RR-2) stormwater runoff from some areas of a development project.

No

Plant or conserve trees to reduce stormwater runoff, increase nutrient uptake, and Tree provide bank stabilization. Trees Planting/Tree can be used for applications such as landscaping, Pit/Tree Trench (RR-3) stormwater management practice areas, conservation areas and erosion and sediment control.

No

Direct runoff from rooftop areas Disconnection and upland overland runoff flow to designated pervious areas to of Rooftop Runoff (RR-4) reduce runoff volumes and rates.

No

RR Techniques

Step 3 - Evaluation of RR Techniques and Standard SMPs with RRv Capacity

Vegetated Swale (RR-5)

The natural drainage paths, or properly designed vegetated channels, can be used instead of constructing underground storm sewers or concrete open channels to increase time of concentration, reduce the peak discharge, and provide infiltration.

Rain Garden (RR-6)

Manage and treat small volumes of stormwater runoff using a conditioned planting soil bed and planting materials to filter runoff stored within a shallow depression.

Small landscaped stormwater treatment devices that can be designed as infiltration or Stormwater filtering practices. Stormwater Planter (RR-7) planters use soil infiltration and biogeochemical processes to decrease stormwater quantity and improve water quality.

No

No

No

Rainwater Harvesting System (RR-8)

Capture and store stormwater runoff to be used for irrigation systems or filtered and reused for non-contact activities.

No

Porous Pavement (RR-9)

Pervious types of pavements that provide an alternative to conventional paved surfaces, designed to infiltrate rainfall through the surface, thereby reducing stormwater runoff from a site and providing some pollutant uptake in the underlying soils.

No

Green Roof (RR-10)

Capture runoff by a layer of vegetation and soil installed on top of a conventional flat or sloped roof. The rooftop vegetation allows evaporation and evapotranspiration processes to reduce volume and discharge rate of runoff entering conveyance system.

No

Step 3 - Evaluation of RR Techniques and Standard SMPs with RRv Capacity

Stream Daylighting (RR-11)

Standard SMPs with RRv Capacity

Infiltration Trench (I-1)

Stream Daylight previouslyculverted/piped streams to restore natural habitats, better attenuate runoff by increasing the storage size, promoting infiltration, and help reduce pollutant loads. An infiltration practice that stores the water quality volume in the void spaces of a gravel trench before it is infiltrated into the ground.

Infiltration Basin (I-2)

An infiltration practice that stores the water quality volume in a shallow depression, before it is infiltrated it into the ground.

Dry Well (I-3)

An infiltration practice similar in design to the infiltration trench, and best suited for treatment of rooftop runoff.

Underground Infiltration System (I-4)

An infiltration practice below grade that stores the water quality volume in premanufactured pipes, vaults or other modular structures, before it is infiltrated into the ground.

Infiltration Bioretention (F-4)

A shallow depression that treats stormwater as it flows through a soil matrix, before it is infiltrated into the ground.

Filtration Bioretention (F-5)

A shallow depression that treats stormwater as it flows through a soil matrix and is returned to the storm drain system.

Permeable engineered soil media that is installed along embankments or other slopes, Bioslope (F-6) designed to capture and treat stormwater runoff from adjacent paved areas. An open drainage channel or depression explicitly designed to Dry Swale (Odetain and promote the filtration 1) of stormwater runoff into the soil media.

No

Yes

No

No

No

Yes

No

No

Yes

Step 4 - Calcuate Minimum RRv Required Enter the Soils Data for the entire site Hydrologic Soil Acres S Group A 6.70 55% B 40% C 30% D 2.62 20% Total Area 9.32 Calculate the Minimum RRv S= 0.45 Impervious = 3.61 Precipitation 1.00 Rv 0.95 Minimum RRv 0.129 5619

acres inches af cf

Infiltration Trench (I-1) Design Point: Enter Site Data For Drainage Area to be Treated by Practice Drainage Area Number

Contributing Area (Acres)

1

0.49

Impervious Percent Area Impervious (Acres) % 0.40

82

Rv

WQv (cf)

Precipitation (in)

Description

0.78

1,396

1.00

Infiltration Trench

Design Criteria Enter underlying soil infiltration rate (based on geotechnical testing, refer to Appendix D) Is the contributing area to the practice an "Infiltration Restricted" stormwater hotspot? Is the contributing area to the practice an "Infiltration Prohibited" stormwater hotspot? Is the contributing area greater than 5 acres? Is the practice located in a sole source aquifer? Enter depth to seasonal high water table (ft) Enter depth to bedrock (ft) Enter pretreatment volume provided (cf) Enter depth of pea gravel (inches) Enter depth of stone reservoir (ft) Is an observation well provided? What slope is the practice located on? (%)

Water Quality Volume Porosity Stone Reservoir Depth Required Surface Area Enter Surface Area Provided RRv Provided

6 No No No No

6 6 563 4 3.5 Yes 2 Sizing Criteria Value Units WQv 1396 cf n 0.40 dt 3.5 ft At 998.00 sf At 1009 sf Determine Runoff Reduction cf 1,396

Notes

Infiltration Bioretention (F-4) Design Point: Enter Site Data For Drainage Area to be Treated by Practice Drainage Area Number

Contributing Area (Acres)

2

2.48

Impervious Percent Area Impervious (Acres) % 2.05

83

Rv

WQv (cf)

Precipitation (in)

Description

0.79

7,147

1.00

Infiltration Bioretention

Design Criteria Enter underlying soil infiltration rate (based on geotechnical testing, refer to Appendix D)

6

Is the contributing area to the practice an "Infiltration Restricted" stormwater hotspot? Is the contributing area to the practice an "Infiltration Prohibited" stormwater hotspot? Is contributing area greater than max. contributing area? Enter depth to seasonal high water table (ft) (4 ft min separation in sole source aquifer) Enter depth to bedrock (ft) Is pretreatment provided, in conformance with Section 6.4.3.1? Enter average height of ponding (ft) Enter depth of surface layer (inches) Enter depth of filter media (ft) Enter depth of drainage layer (inches) Enter slope of maintenance access (%) Enter width of maintenance access (ft)

No No No 6 6 Yes 0.5 3 2.5 10 2 12 Sizing Criteria

Permeability Flow Rate Filter Time Required Filter Area

k tf Af

Value 1 2 2978

Units ft/day days sf

Enter Provided Filter Area

Af

6320

sf

Calculate Runoff Reduction RRv Provided

7,147

cf

Notes

Dry Swale (O-1) Design Point: Enter Site Data For Drainage Area to be Treated by Practice Drainage Area Number

Contributing Area (Acres)

3

3.12

Impervious Percent Area Impervious (Acres) % 0.15

Select HSG Is the contributing area to the practice a designated hotspot? Is the practice the first in series for treatment of a Level 1 (Infiltration Restricted) hotspot? Is contributing area greater than 5 acres? Enter depth to seasonal high water table (ft) Enter depth to bedrock (ft) Enter pretreatment volume provided (cf) Enter depth of filter media (inches) Enter depth of drainage layer (inches) Is an underdrain proposed?

Enter Bottom Width Enter Side Slopes WQv Maximum Flow Depth WQv Flow Top Width Channel Area Required Channel Length Enter Provided Channel Length Channel Volume Provided Enter Check Dam Height Check Dam Spacing Number of Check Dams Required 2-yr 24-hr Flow Depth 2-yr Storm Flow Top Width Area of 2-yr 24-hr Flow 2-yr Wetted Perimeter Enter Mannings Coef. Enter Longitudinal Slope 2-yr Velocity Enter 10-yr Freeboard RRv Provided WQv Treated

b X:1 d Wwqv Awqv Lr Lp Vc Ch Cs C d2 W2 A2 Pw2 n S V

5

Rv

WQv (ft3)

Precipitation (in)

Description

0.09

1,056

1.00

Wet Swale

Design Criteria D No No No 6 6 110 30 10 Yes Sizing Criteria Value Units 3.00 ft 3.00 :1 0.31 ft 4.86 ft 1.22 sf 867.00 ft 950.00 ft 1157.39 cf 0.90 ft 90.00 ft 11.00 0.31 ft 4.86 ft 1.22 sf 5.05 ft 0.03 0.01 ft/ft 1.93 fps 0.53 ft

Notes

Determine Runoff Reduction cf 211 This is the portion of the WQv that is not 845 cf reduced/infiltrated

Contributing Area (Acres)

Impervious Area (Acres)

Percent Impervious %

Rv

WQv (cf)

Precipitation (in)

Description

4

3.23

1.01

31

0.33

3,886

1.00

Micropool Extended Detention Pond

Select pond type

Micropool Extended Detention

Design Criteria Is the pond located within jurisdictional waters? No Enter the natural slope of the pond area (%) 1 Enter underlying soil infiltration rate (based on Does not meet feasibility criteria, provide an 6 geotechnical testing, refer to Appendix D). impermeable liner Has an impermeable liner been provided? Yes Is the pond located within a sole source aquifer? No Is the pond located within a designated hotspot? No Enter depth to seasonal high water table (ft) 6 Enter depth to sound bedrock (ft) 6 List any drainage areas treated by other practices Additional 1 3 3.61 that will be directed to this practice. Areas Is the contributing area less than the minimum Does not meet feasibility criteria Yes contributing area? Will the pond discharge to trout waters? No Has a controlled outlet been provided? GI Worksheet error; 5 acres ok if it Yes meets Water Balance (5.5 feet > Has an emergency spillway been provided? Yes 5.26 feet min.) Has pretreatment been provided per Section Yes 6.1.3? Enter freeboard depth (ft) 1 Enter side slopes above permanent pool (X:1) 5 Enter aquatic bench slope (%) 15 Enter aquatic bench slope to pond floor (X:1) 4 Enter min. aquatic bench width provided (ft) 15 Enter aquatic bench average width provided (ft) 15 Enter aquatic bench depth (inches) 12 Enter maintenance access slope (%) 2 Enter maintenance access width (ft) 12 Enter permanent pool depth (ft) 5.5 Minimum permanent pool depth per Water 5.26 Balance Calculation (ft) Sizing Criteria Notes Value Units Required Water Quality Volume 3886 cf Pretreatment WQv Provided 4305 cf Permanent Pool WQv Provided

4477

cf

Extended Detention WQv Provided 3050 cf Determine the Water Quality Volume Treated Water Quality Volume Treated

0

cf

3,886 cf

AY IRONDEQUOIT WAYNE COUNTY EXPRESSW (NEW YORK ROUTE 104) (R.O.W. VARIES)

WV EX 12" DI WATER MAIN

HYD

EX TG=397.7 (NO COVER) EX INV=395.7 (12" PVC)

12" EX STM @ 0.77%

SUBCATCHMENT (TYP)

1 TIME-OF-CONCENTRATION (TYP)

4

CATCH BASIN T.G.=397.9 INV=395.0

EX 83' 1x2 LOW-HEAD CONCRETE PIPE

EX INV=396.1

EX INV=397.4

5

EX 16" STM

EX INV=400.1

EX INV=397.8 EX 12" STM EX INV=400.3

"LOWES"

2

HY D

3

EX SAN MH RIM=410.4 12" INV=396.60

STORM MANHOLE RIM=403.4

12 "

GUY WIRE

LP LIGHT POLE (TYPICAL)

LP

LP EX CB T.G.=404.8 INV=401.8

EX

60

PSI GA SM AI N

BLACK CHERRY BLVD (70' R.O.W.)

PP

RIP-RAP

EX SAN MH RIM=406.8 INV=397.8

EX 8" DI

EX

HYD

SA N

WV

PP

I. P. FND

EX 12" SAN

PRE-DEVELOPMENT DRAINAGE BOUNDARY MAP

B.J.'S WHOL

1S

4S

North

Off-site to North

2S

1L

Center Site Composite

5S

3S Off-site to Center South

Subcat

Reach

Pond

Link

Routing Diagram for Pre-Development 20260406 Prepared by Vanguard Engineering PC, Printed 4/7/2026 HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Pre-Development 20260406 Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Project Notes Defined 9 rainfall events from NY-Webster extreme precipitation tables IDF Copied 9 events from NY-Webster extreme precipitation tables 24-hr S0P storm

Printed 4/7/2026 Page 2

Pre-Development 20260406 Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Soil Listing (all nodes) Area (acres)

Soil Group

Subcatchment Numbers

10.504 0.000 0.000 8.865 0.000 19.369

HSG A HSG B HSG C HSG D Other

1S, 2S, 3S

1S, 2S, 4S, 5S TOTAL AREA

Printed 4/7/2026 Page 3

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

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Page 4

Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: North

Runoff Area=3.601 ac 0.00% Impervious Runoff Depth=0.24" Flow Length=775' Tc=20.8 min CN=56 Runoff=0.36 cfs 0.073 af

Subcatchment 2S: Center

Runoff Area=7.617 ac 7.33% Impervious Runoff Depth=0.15" Flow Length=1,118' Tc=55.0 min CN=52 Runoff=0.24 cfs 0.092 af

Subcatchment 3S: South

Runoff Area=2.973 ac 11.91% Impervious Runoff Depth=0.04" Flow Length=510' Tc=20.6 min CN=46 Runoff=0.02 cfs 0.011 af

Subcatchment 4S: Off-site to North

Runoff Area=4.500 ac 0.00% Impervious Runoff Depth=0.91" Flow Length=1,250' Tc=78.4 min CN=73 Runoff=1.65 cfs 0.340 af

Subcatchment 5S: Off-site to Center

Runoff Area=0.678 ac 29.35% Impervious Runoff Depth=1.31" Flow Length=1,250' Tc=78.4 min CN=80 Runoff=0.38 cfs 0.074 af

Link 1L: Site Composite

Inflow=2.46 cfs 0.590 af Primary=2.46 cfs 0.590 af

Total Runoff Area = 19.369 ac Runoff Volume = 0.590 af Average Runoff Depth = 0.37" 94.26% Pervious = 18.258 ac 5.74% Impervious = 1.111 ac

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

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Page 5

Summary for Subcatchment 1S: North Runoff = 0.36 cfs @ 12.45 hrs, Volume= Routed to Link 1L : Site Composite

0.073 af, Depth= 0.24"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 2.223 0.310 1.068 3.601 3.601

CN 39 98 80 56

Description Pasture/grassland/range, Good, HSG A Water Surface, 0% imp, HSG A Pasture/grassland/range, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 100 0.0100 0.12 Sheet Flow, start near SE corner, flow N Range n= 0.130 P2= 2.16" 6.1 425 0.0060 1.16 Shallow Concentrated Flow, N, then W through local depression Grassed Waterway Kv= 15.0 fps 0.7 250 5.67 Lake or Reservoir, W, then N through pond Mean Depth= 1.00' 20.8 775 Total

Subcatchment 1S: North Hydrograph 0.4

0.36 cfs

0.38

Runoff

0.36 NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=3.601 ac Runoff Volume=0.073 af Runoff Depth=0.24" Flow Length=775' Tc=20.8 min CN=56

0.34 0.32 0.3 0.28 0.26 Flow (cfs)

0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 2S: Center Runoff = 0.24 cfs @ 13.39 hrs, Volume= Routed to Link 1L : Site Composite

0.092 af, Depth= 0.15"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 1.211 0.063 0.389 0.169 3.398 2.387 7.617 7.059 0.558

CN 39 80 98 98 30 77 52

Description Pasture/grassland/range, Good, HSG A Pasture/grassland/range, Good, HSG D Paved roads w/curbs & sewers, HSG A Paved roads w/curbs & sewers, HSG D Woods, Good, HSG A Woods, Good, HSG D Weighted Average 92.67% Pervious Area 7.33% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.1 100 0.0200 0.06 Sheet Flow, start along SE edge, flow NW Woods: Light underbrush n= 0.400 P2= 2.16" 28.1 753 0.0080 0.45 Shallow Concentrated Flow, N, then W to swale Woodland Kv= 5.0 fps 0.2 65 0.0060 4.61 6.44 Pipe Channel, culvert 16.0" Round Area= 1.4 sf Perim= 4.2' r= 0.33' n= 0.012 Concrete pipe, finished 0.6 200 5.67 Lake or Reservoir, flowing N through pond Mean Depth= 1.00' 55.0 1,118 Total

Page 6

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

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Page 7

Subcatchment 2S: Center

Flow (cfs)

Hydrograph 0.26 0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0

0.24 cfs

Runoff NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=7.617 ac Runoff Volume=0.092 af Runoff Depth=0.15" Flow Length=1,118' Tc=55.0 min CN=52

0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 3S: South Runoff = 0.02 cfs @ 13.71 hrs, Volume= Routed to Link 1L : Site Composite

0.011 af, Depth= 0.04"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 1.046 0.354 1.345 0.228 2.973 2.619 0.354

CN 39 98 30 98 46

Description Pasture/grassland/range, Good, HSG A Paved parking, HSG A Woods, Good, HSG A Water Surface, 0% imp, HSG A Weighted Average 88.09% Pervious Area 11.91% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 35 0.0860 0.09 Sheet Flow, from ridge, flow S through woods Woods: Light underbrush n= 0.400 P2= 2.16" 9.9 65 0.0100 0.11 Sheet Flow, from ridge, flow S through range Range n= 0.130 P2= 2.16" 3.7 171 0.0120 0.77 Shallow Concentrated Flow, SW to wetland Short Grass Pasture Kv= 7.0 fps 0.7 239 5.67 Lake or Reservoir, flowing W through pond Mean Depth= 1.00' 20.6 510 Total

Page 8

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

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Page 9

Subcatchment 3S: South Hydrograph 0.018

0.02 cfs

0.017

Runoff

0.016

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=2.973 ac Runoff Volume=0.011 af Runoff Depth=0.04" Flow Length=510' Tc=20.6 min CN=46

0.015 0.014 0.013 0.012 Flow (cfs)

0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 10

Summary for Subcatchment 4S: Off-site to North Runoff = 1.65 cfs @ 13.15 hrs, Volume= Routed to Link 1L : Site Composite

0.340 af, Depth= 0.91"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 4.500 4.500

CN 73

Description Brush, Good, HSG D 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 4S: Off-site to North Hydrograph

1.65 cfs

Runoff

Flow (cfs)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=4.500 ac Runoff Volume=0.340 af Runoff Depth=0.91" Flow Length=1,250' Tc=78.4 min CN=73

1

0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 11

Summary for Subcatchment 5S: Off-site to Center Runoff = 0.38 cfs @ 13.06 hrs, Volume= Routed to Link 1L : Site Composite

0.074 af, Depth= 1.31"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 0.199 0.479 0.678 0.479 0.199

CN 98 73 80

Description Paved roads w/curbs & sewers, HSG D Brush, Good, HSG D Weighted Average 70.65% Pervious Area 29.35% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 5S: Off-site to Center Hydrograph 0.42 0.4

0.38 cfs

Runoff

0.38 0.36

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=0.678 ac Runoff Volume=0.074 af Runoff Depth=1.31" Flow Length=1,250' Tc=78.4 min CN=80

0.34 0.32 0.3

Flow (cfs)

0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Pre-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 12

Summary for Link 1L: Site Composite Inflow Area = 19.369 ac, 5.74% Impervious, Inflow Depth = 0.37" for 10-yr event Inflow = 2.46 cfs @ 13.15 hrs, Volume= 0.590 af Primary = 2.46 cfs @ 13.15 hrs, Volume= 0.590 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2L Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs

Link 1L: Site Composite Hydrograph

2.46 cfs

Inflow Primary

Inflow Area=19.369 ac

Flow (cfs)

2

1

0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 13

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Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: North

Runoff Area=3.601 ac 0.00% Impervious Runoff Depth=1.13" Flow Length=775' Tc=20.8 min CN=56 Runoff=3.21 cfs 0.338 af

Subcatchment 2S: Center

Runoff Area=7.617 ac 7.33% Impervious Runoff Depth=0.88" Flow Length=1,118' Tc=55.0 min CN=52 Runoff=2.96 cfs 0.556 af

Subcatchment 3S: South

Runoff Area=2.973 ac 11.91% Impervious Runoff Depth=0.54" Flow Length=510' Tc=20.6 min CN=46 Runoff=0.86 cfs 0.135 af

Subcatchment 4S: Off-site to North

Runoff Area=4.500 ac 0.00% Impervious Runoff Depth=2.41" Flow Length=1,250' Tc=78.4 min CN=73 Runoff=4.86 cfs 0.902 af

Subcatchment 5S: Off-site to Center

Runoff Area=0.678 ac 29.35% Impervious Runoff Depth=3.03" Flow Length=1,250' Tc=78.4 min CN=80 Runoff=0.94 cfs 0.171 af

Link 1L: Site Composite

Inflow=10.24 cfs 2.102 af Primary=10.24 cfs 2.102 af

Total Runoff Area = 19.369 ac Runoff Volume = 2.102 af Average Runoff Depth = 1.30" 94.26% Pervious = 18.258 ac 5.74% Impervious = 1.111 ac

Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 14

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 1S: North Runoff = 3.21 cfs @ 12.32 hrs, Volume= Routed to Link 1L : Site Composite

0.338 af, Depth= 1.13"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 2.223 0.310 1.068 3.601 3.601

CN 39 98 80 56

Description Pasture/grassland/range, Good, HSG A Water Surface, 0% imp, HSG A Pasture/grassland/range, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 100 0.0100 0.12 Sheet Flow, start near SE corner, flow N Range n= 0.130 P2= 2.16" 6.1 425 0.0060 1.16 Shallow Concentrated Flow, N, then W through local depression Grassed Waterway Kv= 15.0 fps 0.7 250 5.67 Lake or Reservoir, W, then N through pond Mean Depth= 1.00' 20.8 775 Total

Subcatchment 1S: North Hydrograph

3.21 cfs

Runoff NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=3.601 ac Runoff Volume=0.338 af Runoff Depth=1.13" Flow Length=775' Tc=20.8 min CN=56

Flow (cfs)

3

2

1

0 0

2

4

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8

10

12

14

16

18

20

22 24 26 28 Time (hours)

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Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 15

Summary for Subcatchment 2S: Center Runoff = 2.96 cfs @ 12.89 hrs, Volume= Routed to Link 1L : Site Composite

0.556 af, Depth= 0.88"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 1.211 0.063 0.389 0.169 3.398 2.387 7.617 7.059 0.558

CN 39 80 98 98 30 77 52

Description Pasture/grassland/range, Good, HSG A Pasture/grassland/range, Good, HSG D Paved roads w/curbs & sewers, HSG A Paved roads w/curbs & sewers, HSG D Woods, Good, HSG A Woods, Good, HSG D Weighted Average 92.67% Pervious Area 7.33% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.1 100 0.0200 0.06 Sheet Flow, start along SE edge, flow NW Woods: Light underbrush n= 0.400 P2= 2.16" 28.1 753 0.0080 0.45 Shallow Concentrated Flow, N, then W to swale Woodland Kv= 5.0 fps 0.2 65 0.0060 4.61 6.44 Pipe Channel, culvert 16.0" Round Area= 1.4 sf Perim= 4.2' r= 0.33' n= 0.012 Concrete pipe, finished 0.6 200 5.67 Lake or Reservoir, flowing N through pond Mean Depth= 1.00' 55.0 1,118 Total

Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 16

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Subcatchment 2S: Center Hydrograph

2.96 cfs

3

Runoff NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=7.617 ac Runoff Volume=0.556 af Runoff Depth=0.88" Flow Length=1,118' Tc=55.0 min CN=52

Flow (cfs)

2

1

0 0

2

4

6

8

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12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

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Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 3S: South Runoff = 0.86 cfs @ 12.42 hrs, Volume= Routed to Link 1L : Site Composite

0.135 af, Depth= 0.54"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 1.046 0.354 1.345 0.228 2.973 2.619 0.354

CN 39 98 30 98 46

Description Pasture/grassland/range, Good, HSG A Paved parking, HSG A Woods, Good, HSG A Water Surface, 0% imp, HSG A Weighted Average 88.09% Pervious Area 11.91% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 35 0.0860 0.09 Sheet Flow, from ridge, flow S through woods Woods: Light underbrush n= 0.400 P2= 2.16" 9.9 65 0.0100 0.11 Sheet Flow, from ridge, flow S through range Range n= 0.130 P2= 2.16" 3.7 171 0.0120 0.77 Shallow Concentrated Flow, SW to wetland Short Grass Pasture Kv= 7.0 fps 0.7 239 5.67 Lake or Reservoir, flowing W through pond Mean Depth= 1.00' 20.6 510 Total

Printed 4/7/2026 Page 17

Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 18

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Subcatchment 3S: South Hydrograph 0.95

0.86 cfs

0.9

Runoff

0.85

NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=2.973 ac Runoff Volume=0.135 af Runoff Depth=0.54" Flow Length=510' Tc=20.6 min CN=46

0.8 0.75 0.7 0.65

Flow (cfs)

0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

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Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 19

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 4S: Off-site to North Runoff = 4.86 cfs @ 13.07 hrs, Volume= Routed to Link 1L : Site Composite

0.902 af, Depth= 2.41"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 4.500 4.500

CN 73

Description Brush, Good, HSG D 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 4S: Off-site to North Hydrograph

4.86 cfs

5

Runoff NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=4.500 ac Runoff Volume=0.902 af Runoff Depth=2.41" Flow Length=1,250' Tc=78.4 min CN=73

Flow (cfs)

4

3

2

1

0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

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32

34

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Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 20

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 5S: Off-site to Center Runoff = 0.94 cfs @ 12.99 hrs, Volume= Routed to Link 1L : Site Composite

0.171 af, Depth= 3.03"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 0.199 0.479 0.678 0.479 0.199

CN 98 73 80

Description Paved roads w/curbs & sewers, HSG D Brush, Good, HSG D Weighted Average 70.65% Pervious Area 29.35% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 5S: Off-site to Center Hydrograph 1

0.94 cfs

Runoff

Flow (cfs)

NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=0.678 ac Runoff Volume=0.171 af Runoff Depth=3.03" Flow Length=1,250' Tc=78.4 min CN=80

0 0

2

4

6

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16

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20

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Pre-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 21

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Link 1L: Site Composite Inflow Area = 19.369 ac, 5.74% Impervious, Inflow Depth = 1.30" for 100-yr event Inflow = 10.24 cfs @ 12.90 hrs, Volume= 2.102 af Primary = 10.24 cfs @ 12.90 hrs, Volume= 2.102 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2L Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs

Link 1L: Site Composite Hydrograph 11

10.24 cfs

Inflow Primary

10

Inflow Area=19.369 ac

9 8

Flow (cfs)

7 6 5 4 3 2 1 0 0

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AY IRONDEQUOIT WAYNE COUNTY EXPRESSW (NEW YORK ROUTE 104) (R.O.W. VARIES)

3 STORM WATER MANAGEMENT PRACTICE (TYP) 398 401

1A

2+00

1+00

0+00

3+ 00

400

1

398

401

SUBCATCHMENT (TYP)

4+00

1 TIME-OF-CONCENTRATION (TYP)

5+00

400

400

4

5

5

6+00

402 7+00

401

40

6

401

402

397

2

2 7+26.68

2 40

404 404

2 404

404

403

403

404

405

405

404

405 40

3

405

3 40

404

2

403

5 40

403

401.9

400.5

PLUNGE POOL (10' x 216')

X 399.0

2A

399.0 X

X 401.7

X 400.5 X

X 401.5 X

2

400.5 X

406 401.5 X

4

401

5 BLACK CHERRY BLVD (70' R.O.W.)

401

INFILTRATING BIORETENTION (36' x 205')

10' WIDE BROAD-CRESTED WEIR AT EL=401.50

X

405

402 401.9 X 401.7

POST-DEVELOPMENT DRAINAGE BOUNDARY MAP

1S 1AS

North

North Area Loop Road

1P 3P

Infiltration Trench

North Pond

5S Off-site to North

2S

1L

4P

Site Composite

Revised Center Pond

Center

6S

5P 2P

South Pond

Off-site to Center

Bioretention

4S

2AP

3S Plunge Pool To Bioretention

South

Subcat

Reach

Pond

Link

Routing Diagram for Post-Development 20260406 Prepared by Vanguard Engineering PC, Printed 4/7/2026 HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Post-Development 20260406 Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Project Notes Defined 9 rainfall events from NY-Webster extreme precipitation tables IDF Copied 9 events from NY-Webster extreme precipitation tables 24-hr S0P storm

Printed 4/7/2026 Page 2

Post-Development 20260406 Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Soil Listing (all nodes) Area (acres)

Soil Group

Subcatchment Numbers

10.504 0.000 0.000 8.865 0.000 19.369

HSG A HSG B HSG C HSG D Other

1AS, 1S, 2S, 3S, 4S

1AS, 1S, 2S, 3S, 5S, 6S TOTAL AREA

Printed 4/7/2026 Page 3

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 4

Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1AS: North Area Loop Road

Runoff Area=0.487 ac 82.14% Impervious Runoff Depth=1.81" Tc=6.0 min CN=87 Runoff=1.35 cfs 0.073 af

Subcatchment 1S: North

Runoff Area=2.722 ac 0.00% Impervious Runoff Depth=0.40" Flow Length=795' Tc=20.5 min CN=61 Runoff=0.66 cfs 0.090 af

Subcatchment 2S: Center

Runoff Area=6.713 ac 21.23% Impervious Runoff Depth=0.54" Flow Length=863' Tc=28.3 min CN=65 Runoff=2.29 cfs 0.304 af

Subcatchment 3S: To Bioretention

Runoff Area=2.753 ac 74.50% Impervious Runoff Depth=1.51" Flow Length=75' Slope=0.0200 '/' Tc=13.8 min CN=83 Runoff=4.85 cfs 0.347 af Runoff Area=1.516 ac 0.00% Impervious Runoff Depth=0.00" Flow Length=873' Tc=16.7 min CN=37 Runoff=0.00 cfs 0.000 af

Subcatchment 4S: South Subcatchment 5S: Off-site to North

Runoff Area=4.500 ac 0.00% Impervious Runoff Depth=0.91" Flow Length=1,250' Tc=78.4 min CN=73 Runoff=1.65 cfs 0.340 af

Subcatchment 6S: Off-site to Center

Runoff Area=0.678 ac 29.35% Impervious Runoff Depth=1.31" Flow Length=1,250' Tc=78.4 min CN=80 Runoff=0.38 cfs 0.074 af

Pond 1P: Infiltration Trench

Peak Elev=400.23' Storage=0.028 af Inflow=1.35 cfs 0.073 af Discarded=0.16 cfs 0.073 af Primary=0.00 cfs 0.000 af Outflow=0.16 cfs 0.073 af

Pond 2AP: Plunge Pool

Peak Elev=401.74' Storage=0.064 af Inflow=4.85 cfs 0.347 af Outflow=4.84 cfs 0.285 af

Pond 2P: Bioretention

Peak Elev=400.92' Storage=0.191 af Inflow=4.84 cfs 0.285 af Outflow=0.12 cfs 0.285 af

Pond 3P: North Pond

Peak Elev=398.25' Storage=0.255 af Inflow=1.89 cfs 0.430 af Outflow=0.25 cfs 0.430 af Peak Elev=396.25' Storage=0.231 af Inflow=2.44 cfs 0.378 af 24.0" x 12.0", R=12.0" Arch Culvert n=0.015 L=83.0' S=0.0133 '/' Outflow=0.38 cfs 0.165 af

Pond 4P: Revised Center Pond Pond 5P: South Pond Link 1L: Site Composite

Peak Elev=395.41' Storage=0.007 af Inflow=0.12 cfs 0.285 af 48.0" Round Culvert n=0.012 L=182.0' S=0.0055 '/' Outflow=0.12 cfs 0.285 af Inflow=0.74 cfs 0.880 af Primary=0.74 cfs 0.880 af

Total Runoff Area = 19.369 ac Runoff Volume = 1.228 af Average Runoff Depth = 0.76" 78.96% Pervious = 15.294 ac 21.04% Impervious = 4.075 ac

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 5

Summary for Subcatchment 1AS: North Area Loop Road Runoff = 1.35 cfs @ 12.04 hrs, Volume= Routed to Pond 1P : Infiltration Trench

0.073 af, Depth= 1.81"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 0.087 0.332 0.068 0.487 0.087 0.400

CN 39 98 98 87

Tc Length (min) (feet) 6.0

Description Pasture/grassland/range, Good, HSG A Paved roads w/curbs & sewers, HSG A Paved roads w/curbs & sewers, HSG D Weighted Average 17.86% Pervious Area 82.14% Impervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry,

Subcatchment 1AS: North Area Loop Road Hydrograph

1.35 cfs

Runoff NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=0.487 ac Runoff Volume=0.073 af Runoff Depth=1.81" Tc=6.0 min CN=87

Flow (cfs)

1

0 0

2

4

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8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

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48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 6

Summary for Subcatchment 1S: North Runoff = 0.66 cfs @ 12.35 hrs, Volume= Routed to Pond 3P : North Pond

0.090 af, Depth= 0.40"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 1.421 0.300 1.001 2.722 2.722

CN 39 98 80 61

Description Pasture/grassland/range, Good, HSG A Water Surface, 0% imp, HSG A Pasture/grassland/range, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 100 0.0100 0.12 Sheet Flow, start near SE corner, flow N Range n= 0.130 P2= 2.16" 5.5 385 0.0060 1.16 Shallow Concentrated Flow, N, then W through local depression Grassed Waterway Kv= 15.0 fps 0.3 60 0.0040 3.11 2.44 Pipe Channel, W through culvert 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Corrugated PP, smooth interior 0.7 250 5.67 Lake or Reservoir, W, then N through pond Mean Depth= 1.00' 20.5 795 Total

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 7

Subcatchment 1S: North Hydrograph 0.7

0.66 cfs

Runoff

0.65

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=2.722 ac Runoff Volume=0.090 af Runoff Depth=0.40" Flow Length=795' Tc=20.5 min CN=61

0.6 0.55 0.5

Flow (cfs)

0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

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48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 2S: Center [47] Hint: Peak is 116% of capacity of segment #3 Runoff = 2.29 cfs @ 12.42 hrs, Volume= Routed to Pond 4P : Revised Center Pond

0.304 af, Depth= 0.54"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 1.679 0.244 0.170 0.062 0.009 0.026 1.498 1.950 0.099 0.976 6.713 5.288 1.425

CN 39 98 98 77 98 98 39 80 98 98 65

Description Pasture/grassland/range, Good, HSG A Paved roads w/curbs & sewers, HSG A Paved roads w/curbs & sewers, HSG D Woods, Good, HSG D Roofs, HSG A Roofs, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG D Water Surface, 0% imp, HSG A Paved parking, HSG A Weighted Average 78.77% Pervious Area 21.23% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.3 100 0.0120 0.08 Sheet Flow, start along S edge, flow N Grass: Dense n= 0.240 P2= 2.16" 2.9 133 0.0120 0.77 Shallow Concentrated Flow, N to catch basin Short Grass Pasture Kv= 7.0 fps 1.3 200 0.0026 2.51 1.97 Pipe Channel, storm sewer network 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Corrugated PP, smooth interior 2.5 380 0.0020 2.55 3.13 Pipe Channel, storm sewer network 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 Corrugated PP, smooth interior 0.3 50 0.0016 2.58 4.55 Pipe Channel, storm sewer network 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.012 Corrugated PP, smooth interior 28.3 863 Total

Page 8

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 9

Subcatchment 2S: Center Hydrograph

2.29 cfs

Runoff NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=6.713 ac Runoff Volume=0.304 af Runoff Depth=0.54" Flow Length=863' Tc=28.3 min CN=65

Flow (cfs)

2

1

0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

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48

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Page 10

Summary for Subcatchment 3S: To Bioretention Runoff = 4.85 cfs @ 12.16 hrs, Volume= Routed to Pond 2AP : Plunge Pool

0.347 af, Depth= 1.51"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 0.941 0.700 0.410 0.702 2.753 0.702 2.051

CN 98 98 98 39 83

Description Paved parking, HSG A Roofs, HSG A Roofs, HSG D >75% Grass cover, Good, HSG A Weighted Average 25.50% Pervious Area 74.50% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 75 0.0200 0.09 Sheet Flow, from building edge, flowing SW to plunge pool Grass: Dense n= 0.240 P2= 2.16"

Subcatchment 3S: To Bioretention Hydrograph

4.85 cfs

5

Runoff NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=2.753 ac Runoff Volume=0.347 af Runoff Depth=1.51" Flow Length=75' Slope=0.0200 '/' Tc=13.8 min CN=83

Flow (cfs)

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 4S: South [45] Hint: Runoff=Zero Runoff = 0.00 cfs @ 0.00 hrs, Volume= Routed to Pond 5P : South Pond

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 1.366 0.150 1.516 1.516

CN 30 98 37

Description Woods, Good, HSG A Water Surface, 0% imp, HSG A Weighted Average 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 60 0.0860 0.10 Sheet Flow, from ridge, flow SE through woods Woods: Light underbrush n= 0.400 P2= 2.16" 5.2 365 0.0060 1.16 Shallow Concentrated Flow, SE in channel Grassed Waterway Kv= 15.0 fps 0.7 68 0.0060 1.57 Shallow Concentrated Flow, Concrete lined channel Paved Kv= 20.3 fps 1.1 380 5.67 Lake or Reservoir, flowing W through pond Mean Depth= 1.00' 16.7 873 Total

Page 11

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 12

Subcatchment 4S: South Hydrograph 1 Runoff

Flow (cfs)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=1.516 ac Runoff Volume=0.000 af Runoff Depth=0.00" Flow Length=873' Tc=16.7 min CN=37

0.00 cfs 0 0

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 13

Summary for Subcatchment 5S: Off-site to North Runoff = 1.65 cfs @ 13.15 hrs, Volume= Routed to Pond 3P : North Pond

0.340 af, Depth= 0.91"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 4.500 4.500

CN 73

Description Brush, Good, HSG D 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 5S: Off-site to North Hydrograph

1.65 cfs

Runoff

Flow (cfs)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=4.500 ac Runoff Volume=0.340 af Runoff Depth=0.91" Flow Length=1,250' Tc=78.4 min CN=73

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 14

Summary for Subcatchment 6S: Off-site to Center Runoff = 0.38 cfs @ 13.06 hrs, Volume= Routed to Pond 4P : Revised Center Pond

0.074 af, Depth= 1.31"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Area (ac) 0.199 0.479 0.678 0.479 0.199

CN 98 73 80

Description Paved roads w/curbs & sewers, HSG D Brush, Good, HSG D Weighted Average 70.65% Pervious Area 29.35% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 6S: Off-site to Center Hydrograph 0.42 0.4

0.38 cfs

Runoff

0.38 0.36

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Runoff Area=0.678 ac Runoff Volume=0.074 af Runoff Depth=1.31" Flow Length=1,250' Tc=78.4 min CN=80

0.34 0.32 0.3

Flow (cfs)

0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0

2

4

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 15

Summary for Pond 1P: Infiltration Trench Inflow Area = 0.487 ac, 82.14% Impervious, Inflow Depth = 1.81" for 10-yr event Inflow = 1.35 cfs @ 12.04 hrs, Volume= 0.073 af Outflow = 0.16 cfs @ 12.65 hrs, Volume= 0.073 af, Atten= 88%, Lag= 36.3 min Discarded = 0.16 cfs @ 12.65 hrs, Volume= 0.073 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 3P : North Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 4 Peak Elev= 400.23' @ 12.65 hrs Surf.Area= 0.023 ac Storage= 0.028 af Plug-Flow detention time=62.2 min calculated for 0.073 af (100% of inflow) Center-of-Mass det. time=62.2 min ( 869.7 - 807.5 ) Volume #1

Invert 397.20'

Elevation (feet) 397.20 397.30 400.85

Surf.Area Voids (acres) (%) 0.023 0.0 0.023 40.0 0.023 40.0

Device Routing #1 Primary

#2

Avail.Storage Storage Description 0.034 af Custom Stage Data (Prismatic) Listed below (Recalc)

Discarded

Inc.Store (acre-feet) 0.000 0.001 0.033

Cum.Store (acre-feet) 0.000 0.001 0.034

Invert Outlet Devices 400.80' 505.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 397.20' 5.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.00'

Discarded OutFlow Max=0.16 cfs @ 12.65 hrs HW=400.23' (Free Discharge) 2=Exfiltration ( Controls 0.16 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=397.20' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 16

Pond 1P: Infiltration Trench Hydrograph

1.35 cfs

Inflow Outflow Discarded Primary

Inflow Area=0.487 ac Peak Elev=400.23' Storage=0.028 af

Flow (cfs)

1

0.16 cfs 0.00 cfs 0 0

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 17

Summary for Pond 2AP: Plunge Pool Inflow Area = 2.753 ac, 74.50% Impervious, Inflow Depth = 1.51" for 10-yr event Inflow = 4.85 cfs @ 12.16 hrs, Volume= 0.347 af Outflow = 4.84 cfs @ 12.17 hrs, Volume= 0.285 af, Atten= 0%, Lag= 0.2 min Primary = 4.84 cfs @ 12.17 hrs, Volume= 0.285 af Routed to Pond 2P : Bioretention Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 401.74' @ 12.17 hrs Surf.Area= 0.046 ac Storage= 0.064 af Flood Elev= 401.90' Surf.Area= 0.049 ac Storage= 0.071 af Plug-Flow detention time=95.6 min calculated for 0.285 af (82% of inflow) Center-of-Mass det. time=26.5 min ( 853.0 - 826.5 ) Volume #1 Elevation (feet) 399.00 401.90

Invert 399.00'

Avail.Storage Storage Description 0.071 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.049

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.071

Cum.Store (acre-feet) 0.000 0.071

Invert Outlet Devices 401.70' 215.0' long + 5.0 '/' SideZ x 3.0' 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 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32

Primary OutFlow Max=4.64 cfs @ 12.17 hrs HW=401.74' (Free Discharge) 1=Broad-Crested Rectangular Weir (Weir Controls 4.64 cfs @ 0.50 fps)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 18

Pond 2AP: Plunge Pool Hydrograph

4.85 4.84 cfs

5

Inflow Primary

Inflow Area=2.753 ac Peak Elev=401.74' Storage=0.064 af

Flow (cfs)

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 19

Summary for Pond 2P: Bioretention Inflow Area = 2.753 ac, 74.50% Impervious, Inflow Depth = 1.24" for 10-yr event Inflow = 4.84 cfs @ 12.17 hrs, Volume= 0.285 af Outflow = 0.12 cfs @ 17.03 hrs, Volume= 0.285 af, Atten= 97%, Lag= 291.6 min Primary = 0.12 cfs @ 17.03 hrs, Volume= 0.285 af Routed to Pond 5P : South Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 400.92' @ 17.03 hrs Surf.Area= 0.159 ac Storage= 0.191 af Flood Elev= 402.30' Surf.Area= 0.190 ac Storage= 0.382 af Plug-Flow detention time=778.9 min calculated for 0.285 af (100% of inflow) Center-of-Mass det. time=779.0 min ( 1,632.0 - 853.0 ) Volume #1

Invert 396.92'

Elevation (feet) 396.92 397.75 400.50 401.50 402.00

Surf.Area Voids (acres) (%) 0.145 0.0 0.145 40.0 0.145 20.0 0.179 100.0 0.190 100.0

Device Routing #1 Primary #2

Avail.Storage Storage Description 0.382 af Custom Stage Data (Prismatic) Listed below (Recalc)

Primary

Inc.Store (acre-feet) 0.000 0.048 0.080 0.162 0.092

Cum.Store (acre-feet) 0.000 0.048 0.128 0.290 0.382

Invert Outlet Devices 396.92' 0.500 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.30' 401.50' 20.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=0.12 cfs @ 17.03 hrs HW=400.92' (Free Discharge) 1=Exfiltration ( Controls 0.12 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 20

Pond 2P: Bioretention Hydrograph

4.84 cfs

5

Inflow Primary

Inflow Area=2.753 ac Peak Elev=400.92' Storage=0.191 af

Flow (cfs)

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 21

Summary for Pond 3P: North Pond Inflow Area = 7.709 ac, 5.19% Impervious, Inflow Depth = 0.67" for 10-yr event Inflow = 1.89 cfs @ 13.07 hrs, Volume= 0.430 af Outflow = 0.25 cfs @ 16.86 hrs, Volume= 0.430 af, Atten= 87%, Lag= 227.7 min Primary = 0.25 cfs @ 16.86 hrs, Volume= 0.430 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Starting Elev= 397.00' Surf.Area= 0.007 ac Storage= 0.005 af Peak Elev= 398.25' @ 16.86 hrs Surf.Area= 0.372 ac Storage= 0.255 af (0.250 af above start) Flood Elev= 400.00' Surf.Area= 1.560 ac Storage= 1.637 af (1.633 af above start) Plug-Flow detention time=532.8 min calculated for 0.425 af (99% of inflow) Center-of-Mass det. time=519.2 min ( 1,431.9 - 912.7 ) Volume #1

Invert 395.70'

Elevation (feet) 395.70 397.00 398.00 399.00 400.00

Avail.Storage Storage Description 1.637 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.007 0.320 0.529 1.560

Device Routing #1 Primary #2 #3

Device 1 Device 1

#4

Primary

Inc.Store (acre-feet) 0.000 0.005 0.164 0.425 1.045

Cum.Store (acre-feet) 0.000 0.005 0.168 0.593 1.637

Invert Outlet Devices 395.70' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 395.70' / 395.50' S= 0.0077 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf 397.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.50' 24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.90' 10.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=0.25 cfs @ 16.86 hrs HW=398.25' (Free Discharge) 1=Culvert (Passes 0.25 cfs of 5.42 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.25 cfs @ 5.11 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 22

Pond 3P: North Pond Hydrograph 2

1.89 cfs

Inflow Primary

Flow (cfs)

Inflow Area=7.709 ac Peak Elev=398.25' Storage=0.255 af 1

0.25 cfs

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Pond 4P: Revised Center Pond Inflow Area = 7.391 ac, 21.97% Impervious, Inflow Depth = 0.61" for 10-yr event Inflow = 2.44 cfs @ 12.45 hrs, Volume= 0.378 af Outflow = 0.38 cfs @ 14.90 hrs, Volume= 0.165 af, Atten= 85%, Lag= 147.0 min Primary = 0.38 cfs @ 14.90 hrs, Volume= 0.165 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 396.25' @ 14.90 hrs Surf.Area= 0.131 ac Storage= 0.231 af Flood Elev= 399.00' Surf.Area= 0.361 ac Storage= 0.950 af Plug-Flow detention time=338.1 min calculated for 0.165 af (44% of inflow) Center-of-Mass det. time=201.9 min ( 1,097.1 - 895.2 ) Volume #1 Elevation (feet) 390.60 391.00 392.00 393.00 394.00 395.00 396.00 397.00 398.00 399.00

Invert 390.60'

Avail.Storage Storage Description 0.950 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.004 0.013 0.026 0.044 0.067 0.099 0.227 0.291 0.361

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.001 0.008 0.019 0.035 0.055 0.083 0.163 0.259 0.326

Cum.Store (acre-feet) 0.000 0.001 0.009 0.029 0.064 0.119 0.202 0.365 0.624 0.950

Invert Outlet Devices 396.10' 24.0" W x 12.0" H, R=12.0" Arch Culvert L= 83.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 396.10' / 395.00' S= 0.0133 '/' Cc= 0.900 n= 0.015 Concrete sewer w/manholes & inlets, Flow Area= 1.57 sf

Primary OutFlow Max=0.37 cfs @ 14.90 hrs HW=396.25' (Free Discharge) 1=Culvert (Inlet Controls 0.37 cfs @ 1.24 fps)

Page 23

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 24

Pond 4P: Revised Center Pond Hydrograph

2.44 cfs

Inflow Primary

Inflow Area=7.391 ac Peak Elev=396.25' Storage=0.231 af 24.0" x 12.0" R=12.0" Arch Culvert n=0.015 L=83.0' S=0.0133 '/'

Flow (cfs)

2

1

0.38 cfs

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Pond 5P: South Pond Inflow Area = 4.269 ac, 48.04% Impervious, Inflow Depth > 0.80" for 10-yr event Inflow = 0.12 cfs @ 17.03 hrs, Volume= 0.285 af Outflow = 0.12 cfs @ 18.01 hrs, Volume= 0.285 af, Atten= 0%, Lag= 59.2 min Primary = 0.12 cfs @ 18.01 hrs, Volume= 0.285 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 395.41' @ 18.01 hrs Surf.Area= 0.035 ac Storage= 0.007 af Plug-Flow detention time=41.6 min calculated for 0.285 af (100% of inflow) Center-of-Mass det. time=40.8 min ( 1,672.8 - 1,632.0 ) Volume #1 Elevation (feet) 395.00 397.00 398.00 399.00 400.00 401.00 402.00 403.00

Invert 395.00'

Avail.Storage Storage Description 5.026 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.170 0.322 0.498 0.658 0.862 1.376 2.111

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.170 0.246 0.410 0.578 0.760 1.119 1.743

Cum.Store (acre-feet) 0.000 0.170 0.416 0.826 1.404 2.164 3.283 5.026

Invert Outlet Devices 395.00' 48.0" Round Culvert L= 182.0' RCP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 395.00' / 394.00' S= 0.0055 '/' Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 12.57 sf

Primary OutFlow Max=0.12 cfs @ 18.01 hrs HW=395.41' TW=395.40' (TW follows 0.01' below HW) 1=Culvert (Outlet Controls 0.12 cfs @ 0.28 fps)

Page 25

NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 26

Pond 5P: South Pond Hydrograph

0.12 0.12cfs cfs

0.13 0.12

Inflow Area=4.269 ac Peak Elev=395.41' Storage=0.007 af 48.0" Round Culvert n=0.012 L=182.0' S=0.0055 '/'

0.11 0.1 0.09 Flow (cfs)

Inflow Primary

0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0

2

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NY-Webster extreme precipitation tables 24-hr S0P 10-yr Rainfall=3.08" Printed 4/7/2026 Prepared by Vanguard Engineering PC

Post-Development 20260406

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Page 27

Summary for Link 1L: Site Composite Inflow Area = Inflow = Primary =

19.369 ac, 21.04% Impervious, Inflow Depth > 0.55" for 10-yr event 0.74 cfs @ 14.94 hrs, Volume= 0.880 af 0.74 cfs @ 14.94 hrs, Volume= 0.880 af, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs

Link 1L: Site Composite Hydrograph 0.8

0.74 cfs

0.75

Inflow Primary

Inflow Area=19.369 ac

0.7 0.65 0.6 0.55 Flow (cfs)

0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 0

2

4

6

8

10

12

14

16

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Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 28

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1AS: North Area Loop Road

Runoff Area=0.487 ac 82.14% Impervious Runoff Depth=3.72" Tc=6.0 min CN=87 Runoff=2.54 cfs 0.151 af

Subcatchment 1S: North

Runoff Area=2.722 ac 0.00% Impervious Runoff Depth=1.47" Flow Length=795' Tc=20.5 min CN=61 Runoff=3.47 cfs 0.333 af

Subcatchment 2S: Center

Runoff Area=6.713 ac 21.23% Impervious Runoff Depth=1.76" Flow Length=863' Tc=28.3 min CN=65 Runoff=9.17 cfs 0.985 af

Subcatchment 3S: To Bioretention

Runoff Area=2.753 ac 74.50% Impervious Runoff Depth=3.32" Flow Length=75' Slope=0.0200 '/' Tc=13.8 min CN=83 Runoff=10.20 cfs 0.761 af Runoff Area=1.516 ac 0.00% Impervious Runoff Depth=0.16" Flow Length=873' Tc=16.7 min CN=37 Runoff=0.06 cfs 0.021 af

Subcatchment 4S: South Subcatchment 5S: Off-site to North

Runoff Area=4.500 ac 0.00% Impervious Runoff Depth=2.41" Flow Length=1,250' Tc=78.4 min CN=73 Runoff=4.86 cfs 0.902 af

Subcatchment 6S: Off-site to Center

Runoff Area=0.678 ac 29.35% Impervious Runoff Depth=3.03" Flow Length=1,250' Tc=78.4 min CN=80 Runoff=0.94 cfs 0.171 af

Pond 1P: Infiltration Trench

Peak Elev=400.81' Storage=0.033 af Inflow=2.54 cfs 0.151 af Discarded=0.17 cfs 0.106 af Primary=2.28 cfs 0.045 af Outflow=2.45 cfs 0.151 af

Pond 2AP: Plunge Pool

Peak Elev=401.77' Storage=0.065 af Inflow=10.20 cfs 0.761 af Outflow=10.19 cfs 0.700 af

Pond 2P: Bioretention

Peak Elev=401.67' Storage=0.321 af Inflow=10.19 cfs 0.700 af Outflow=4.11 cfs 0.650 af

Pond 3P: North Pond

Peak Elev=398.79' Storage=0.488 af Inflow=5.89 cfs 1.280 af Outflow=4.49 cfs 1.279 af Peak Elev=397.03' Storage=0.373 af Inflow=9.56 cfs 1.156 af 24.0" x 12.0", R=12.0" Arch Culvert n=0.015 L=83.0' S=0.0133 '/' Outflow=5.13 cfs 0.944 af

Pond 4P: Revised Center Pond Pond 5P: South Pond Link 1L: Site Composite

Peak Elev=396.58' Storage=0.106 af Inflow=4.13 cfs 0.671 af 48.0" Round Culvert n=0.012 L=182.0' S=0.0055 '/' Outflow=1.49 cfs 0.666 af Inflow=9.95 cfs 2.888 af Primary=9.95 cfs 2.888 af

Total Runoff Area = 19.369 ac Runoff Volume = 3.325 af Average Runoff Depth = 2.06" 78.96% Pervious = 15.294 ac 21.04% Impervious = 4.075 ac

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 29

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 1AS: North Area Loop Road Runoff = 2.54 cfs @ 12.04 hrs, Volume= Routed to Pond 1P : Infiltration Trench

0.151 af, Depth= 3.72"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 0.087 0.332 0.068 0.487 0.087 0.400

CN 39 98 98 87

Tc Length (min) (feet) 6.0

Description Pasture/grassland/range, Good, HSG A Paved roads w/curbs & sewers, HSG A Paved roads w/curbs & sewers, HSG D Weighted Average 17.86% Pervious Area 82.14% Impervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Direct Entry,

Subcatchment 1AS: North Area Loop Road Hydrograph

2.54 cfs

Runoff NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=0.487 ac Runoff Volume=0.151 af Runoff Depth=3.72" Tc=6.0 min CN=87

Flow (cfs)

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Printed 4/7/2026 Page 30

Summary for Subcatchment 1S: North [47] Hint: Peak is 142% of capacity of segment #3 Runoff = 3.47 cfs @ 12.28 hrs, Volume= Routed to Pond 3P : North Pond

0.333 af, Depth= 1.47"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 1.421 0.300 1.001 2.722 2.722

CN 39 98 80 61

Description Pasture/grassland/range, Good, HSG A Water Surface, 0% imp, HSG A Pasture/grassland/range, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.0 100 0.0100 0.12 Sheet Flow, start near SE corner, flow N Range n= 0.130 P2= 2.16" 5.5 385 0.0060 1.16 Shallow Concentrated Flow, N, then W through local depression Grassed Waterway Kv= 15.0 fps 0.3 60 0.0040 3.11 2.44 Pipe Channel, W through culvert 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Corrugated PP, smooth interior 0.7 250 5.67 Lake or Reservoir, W, then N through pond Mean Depth= 1.00' 20.5 795 Total

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 31

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Subcatchment 1S: North Hydrograph

3.47 cfs

Runoff NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=2.722 ac Runoff Volume=0.333 af Runoff Depth=1.47" Flow Length=795' Tc=20.5 min CN=61

Flow (cfs)

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Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 2S: Center [47] Hint: Peak is 466% of capacity of segment #3 [47] Hint: Peak is 293% of capacity of segment #4 [47] Hint: Peak is 201% of capacity of segment #5 Runoff = 9.17 cfs @ 12.39 hrs, Volume= Routed to Pond 4P : Revised Center Pond

0.985 af, Depth= 1.76"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 1.679 0.244 0.170 0.062 0.009 0.026 1.498 1.950 0.099 0.976 6.713 5.288 1.425

CN 39 98 98 77 98 98 39 80 98 98 65

Description Pasture/grassland/range, Good, HSG A Paved roads w/curbs & sewers, HSG A Paved roads w/curbs & sewers, HSG D Woods, Good, HSG D Roofs, HSG A Roofs, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG D Water Surface, 0% imp, HSG A Paved parking, HSG A Weighted Average 78.77% Pervious Area 21.23% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.3 100 0.0120 0.08 Sheet Flow, start along S edge, flow N Grass: Dense n= 0.240 P2= 2.16" 2.9 133 0.0120 0.77 Shallow Concentrated Flow, N to catch basin Short Grass Pasture Kv= 7.0 fps 1.3 200 0.0026 2.51 1.97 Pipe Channel, storm sewer network 12.0" Round Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 Corrugated PP, smooth interior 2.5 380 0.0020 2.55 3.13 Pipe Channel, storm sewer network 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.012 Corrugated PP, smooth interior 0.3 50 0.0016 2.58 4.55 Pipe Channel, storm sewer network 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.012 Corrugated PP, smooth interior 28.3 863 Total

Printed 4/7/2026 Page 32

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 33

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Subcatchment 2S: Center Hydrograph 10

9.17 cfs

Runoff

9

NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=6.713 ac Runoff Volume=0.985 af Runoff Depth=1.76" Flow Length=863' Tc=28.3 min CN=65

8

Flow (cfs)

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Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Subcatchment 3S: To Bioretention Runoff = 10.20 cfs @ 12.16 hrs, Volume= Routed to Pond 2AP : Plunge Pool

0.761 af, Depth= 3.32"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 0.941 0.700 0.410 0.702 2.753 0.702 2.051

CN 98 98 98 39 83

Description Paved parking, HSG A Roofs, HSG A Roofs, HSG D >75% Grass cover, Good, HSG A Weighted Average 25.50% Pervious Area 74.50% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.8 75 0.0200 0.09 Sheet Flow, from building edge, flowing SW to plunge pool Grass: Dense n= 0.240 P2= 2.16"

Subcatchment 3S: To Bioretention Hydrograph 11

10.20 cfs

Runoff

10

NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=2.753 ac Runoff Volume=0.761 af Runoff Depth=3.32" Flow Length=75' Slope=0.0200 '/' Tc=13.8 min CN=83

9 8

Flow (cfs)

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Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 35

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Summary for Subcatchment 4S: South Runoff = 0.06 cfs @ 13.08 hrs, Volume= Routed to Pond 5P : South Pond

0.021 af, Depth= 0.16"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 1.366 0.150 1.516 1.516

CN 30 98 37

Description Woods, Good, HSG A Water Surface, 0% imp, HSG A Weighted Average 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 60 0.0860 0.10 Sheet Flow, from ridge, flow SE through woods Woods: Light underbrush n= 0.400 P2= 2.16" 5.2 365 0.0060 1.16 Shallow Concentrated Flow, SE in channel Grassed Waterway Kv= 15.0 fps 0.7 68 0.0060 1.57 Shallow Concentrated Flow, Concrete lined channel Paved Kv= 20.3 fps 1.1 380 5.67 Lake or Reservoir, flowing W through pond Mean Depth= 1.00' 16.7 873 Total

Subcatchment 4S: South Hydrograph 0.065

0.06 cfs

Runoff

0.06

NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=1.516 ac Runoff Volume=0.021 af Runoff Depth=0.16" Flow Length=873' Tc=16.7 min CN=37

0.055 0.05

Flow (cfs)

0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 0

2

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Summary for Subcatchment 5S: Off-site to North Runoff = 4.86 cfs @ 13.07 hrs, Volume= Routed to Pond 3P : North Pond

0.902 af, Depth= 2.41"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 4.500 4.500

CN 73

Description Brush, Good, HSG D 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 5S: Off-site to North Hydrograph

4.86 cfs

5

Runoff NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=4.500 ac Runoff Volume=0.902 af Runoff Depth=2.41" Flow Length=1,250' Tc=78.4 min CN=73

Flow (cfs)

4

3

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Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 37

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Summary for Subcatchment 6S: Off-site to Center Runoff = 0.94 cfs @ 12.99 hrs, Volume= Routed to Pond 4P : Revised Center Pond

0.171 af, Depth= 3.03"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Area (ac) 0.199 0.479 0.678 0.479 0.199

CN 98 73 80

Description Paved roads w/curbs & sewers, HSG D Brush, Good, HSG D Weighted Average 70.65% Pervious Area 29.35% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 45.5 100 0.0050 0.04 Sheet Flow, start along S edge, flow N Woods: Light underbrush n= 0.400 P2= 2.16" 31.9 800 0.0070 0.42 Shallow Concentrated Flow, N, then W to pond Woodland Kv= 5.0 fps 1.0 350 5.67 Lake or Reservoir, W through pond Mean Depth= 1.00' 78.4 1,250 Total

Subcatchment 6S: Off-site to Center Hydrograph 1

0.94 cfs

Runoff

Flow (cfs)

NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Runoff Area=0.678 ac Runoff Volume=0.171 af Runoff Depth=3.03" Flow Length=1,250' Tc=78.4 min CN=80

0 0

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Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 38

Summary for Pond 1P: Infiltration Trench Inflow Area = 0.487 ac, 82.14% Impervious, Inflow Depth = 3.72" for 100-yr event Inflow = 2.54 cfs @ 12.04 hrs, Volume= 0.151 af Outflow = 2.45 cfs @ 12.06 hrs, Volume= 0.151 af, Atten= 3%, Lag= 1.3 min Discarded = 0.17 cfs @ 12.06 hrs, Volume= 0.106 af Primary = 2.28 cfs @ 12.06 hrs, Volume= 0.045 af Routed to Pond 3P : North Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 4 Peak Elev= 400.81' @ 12.06 hrs Surf.Area= 0.023 ac Storage= 0.033 af Plug-Flow detention time=55.3 min calculated for 0.151 af (100% of inflow) Center-of-Mass det. time=53.9 min ( 838.4 - 784.5 ) Volume #1

Invert 397.20'

Elevation (feet) 397.20 397.30 400.85

Surf.Area Voids (acres) (%) 0.023 0.0 0.023 40.0 0.023 40.0

Device Routing #1 Primary

#2

Avail.Storage Storage Description 0.034 af Custom Stage Data (Prismatic) Listed below (Recalc)

Discarded

Inc.Store (acre-feet) 0.000 0.001 0.033

Cum.Store (acre-feet) 0.000 0.001 0.034

Invert Outlet Devices 400.80' 505.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 397.20' 5.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.00'

Discarded OutFlow Max=0.17 cfs @ 12.06 hrs HW=400.81' (Free Discharge) 2=Exfiltration ( Controls 0.17 cfs) Primary OutFlow Max=2.20 cfs @ 12.06 hrs HW=400.81' (Free Discharge) 1=Broad-Crested Rectangular Weir (Weir Controls 2.20 cfs @ 0.32 fps)

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 39

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Pond 1P: Infiltration Trench Hydrograph

2.54 cfs 2.45 cfs 2.28 cfs

Inflow Outflow Discarded Primary

Inflow Area=0.487 ac Peak Elev=400.81' Storage=0.033 af

Flow (cfs)

2

1

0.17 cfs 0 0

2

4

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Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 40

Summary for Pond 2AP: Plunge Pool Inflow Area = 2.753 ac, 74.50% Impervious, Inflow Depth = 3.32" for 100-yr event Inflow = 10.20 cfs @ 12.16 hrs, Volume= 0.761 af Outflow = 10.19 cfs @ 12.16 hrs, Volume= 0.700 af, Atten= 0%, Lag= 0.1 min Primary = 10.19 cfs @ 12.16 hrs, Volume= 0.700 af Routed to Pond 2P : Bioretention Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 401.77' @ 12.16 hrs Surf.Area= 0.047 ac Storage= 0.065 af Flood Elev= 401.90' Surf.Area= 0.049 ac Storage= 0.071 af Plug-Flow detention time=51.1 min calculated for 0.700 af (92% of inflow) Center-of-Mass det. time=13.1 min ( 813.6 - 800.5 ) Volume #1 Elevation (feet) 399.00 401.90

Invert 399.00'

Avail.Storage Storage Description 0.071 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.049

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.071

Cum.Store (acre-feet) 0.000 0.071

Invert Outlet Devices 401.70' 215.0' long + 5.0 '/' SideZ x 3.0' 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 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32

Primary OutFlow Max=10.03 cfs @ 12.16 hrs HW=401.77' (Free Discharge) 1=Broad-Crested Rectangular Weir (Weir Controls 10.03 cfs @ 0.65 fps)

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 41

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Pond 2AP: Plunge Pool Hydrograph 11

10.19 cfs 10.20

Inflow Primary

10

Inflow Area=2.753 ac Peak Elev=401.77' Storage=0.065 af

9 8

Flow (cfs)

7 6 5 4 3 2 1 0 0

2

4

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Printed 4/7/2026 Page 42

Summary for Pond 2P: Bioretention Inflow Area = 2.753 ac, 74.50% Impervious, Inflow Depth = 3.05" for 100-yr event Inflow = 10.19 cfs @ 12.16 hrs, Volume= 0.700 af Outflow = 4.11 cfs @ 12.47 hrs, Volume= 0.650 af, Atten= 60%, Lag= 18.7 min Primary = 4.11 cfs @ 12.47 hrs, Volume= 0.650 af Routed to Pond 5P : South Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 401.67' @ 12.47 hrs Surf.Area= 0.183 ac Storage= 0.321 af Flood Elev= 402.30' Surf.Area= 0.190 ac Storage= 0.382 af Plug-Flow detention time=536.5 min calculated for 0.650 af (93% of inflow) Center-of-Mass det. time=501.8 min ( 1,315.4 - 813.6 ) Volume #1

Invert 396.92'

Elevation (feet) 396.92 397.75 400.50 401.50 402.00

Surf.Area Voids (acres) (%) 0.145 0.0 0.145 40.0 0.145 20.0 0.179 100.0 0.190 100.0

Device Routing #1 Primary #2

Avail.Storage Storage Description 0.382 af Custom Stage Data (Prismatic) Listed below (Recalc)

Primary

Inc.Store (acre-feet) 0.000 0.048 0.080 0.162 0.092

Cum.Store (acre-feet) 0.000 0.048 0.128 0.290 0.382

Invert Outlet Devices 396.92' 0.500 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.30' 401.50' 20.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=4.07 cfs @ 12.47 hrs HW=401.67' (Free Discharge) 1=Exfiltration ( Controls 0.15 cfs) 2=Broad-Crested Rectangular Weir (Weir Controls 3.93 cfs @ 1.11 fps)

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 43

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Pond 2P: Bioretention Hydrograph 11

10.19 cfs

Inflow Primary

10

Inflow Area=2.753 ac Peak Elev=401.67' Storage=0.321 af

9 8

Flow (cfs)

7 6 5

4.11 cfs

4 3 2 1 0 0

2

4

6

8

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14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 44

Summary for Pond 3P: North Pond Inflow Area = 7.709 ac, 5.19% Impervious, Inflow Depth = 1.99" for 100-yr event Inflow = 5.89 cfs @ 12.98 hrs, Volume= 1.280 af Outflow = 4.49 cfs @ 13.50 hrs, Volume= 1.279 af, Atten= 24%, Lag= 31.3 min Primary = 4.49 cfs @ 13.50 hrs, Volume= 1.279 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Starting Elev= 397.00' Surf.Area= 0.007 ac Storage= 0.005 af Peak Elev= 398.79' @ 13.50 hrs Surf.Area= 0.486 ac Storage= 0.488 af (0.484 af above start) Flood Elev= 400.00' Surf.Area= 1.560 ac Storage= 1.637 af (1.633 af above start) Plug-Flow detention time=353.9 min calculated for 1.274 af (100% of inflow) Center-of-Mass det. time=349.6 min ( 1,216.5 - 866.9 ) Volume #1

Invert 395.70'

Elevation (feet) 395.70 397.00 398.00 399.00 400.00

Avail.Storage Storage Description 1.637 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.007 0.320 0.529 1.560

Device Routing #1 Primary #2 #3

Device 1 Device 1

#4

Primary

Inc.Store (acre-feet) 0.000 0.005 0.164 0.425 1.045

Cum.Store (acre-feet) 0.000 0.005 0.168 0.593 1.637

Invert Outlet Devices 395.70' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 395.70' / 395.50' S= 0.0077 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf 397.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.50' 24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.90' 10.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=4.49 cfs @ 13.50 hrs HW=398.79' (Free Discharge) 1=Culvert (Passes 4.49 cfs of 6.09 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.31 cfs @ 6.22 fps) 3=Orifice/Grate (Weir Controls 4.18 cfs @ 1.78 fps) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 45

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Pond 3P: North Pond Hydrograph

5.89 cfs

6

5

Inflow Primary

Inflow Area=7.709 ac Peak Elev=398.79' Storage=0.488 af

4.49 cfs

Flow (cfs)

4

3

2

1

0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 46

Summary for Pond 4P: Revised Center Pond Inflow Area = 7.391 ac, 21.97% Impervious, Inflow Depth = 1.88" for 100-yr event Inflow = 9.56 cfs @ 12.39 hrs, Volume= 1.156 af Outflow = 5.13 cfs @ 12.89 hrs, Volume= 0.944 af, Atten= 46%, Lag= 29.8 min Primary = 5.13 cfs @ 12.89 hrs, Volume= 0.944 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 397.03' @ 12.89 hrs Surf.Area= 0.229 ac Storage= 0.373 af Flood Elev= 399.00' Surf.Area= 0.361 ac Storage= 0.950 af Plug-Flow detention time=122.2 min calculated for 0.944 af (82% of inflow) Center-of-Mass det. time=54.1 min ( 905.3 - 851.2 ) Volume #1 Elevation (feet) 390.60 391.00 392.00 393.00 394.00 395.00 396.00 397.00 398.00 399.00

Invert 390.60'

Avail.Storage Storage Description 0.950 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.004 0.013 0.026 0.044 0.067 0.099 0.227 0.291 0.361

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.001 0.008 0.019 0.035 0.055 0.083 0.163 0.259 0.326

Cum.Store (acre-feet) 0.000 0.001 0.009 0.029 0.064 0.119 0.202 0.365 0.624 0.950

Invert Outlet Devices 396.10' 24.0" W x 12.0" H, R=12.0" Arch Culvert L= 83.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 396.10' / 395.00' S= 0.0133 '/' Cc= 0.900 n= 0.015 Concrete sewer w/manholes & inlets, Flow Area= 1.57 sf

Primary OutFlow Max=5.13 cfs @ 12.89 hrs HW=397.03' (Free Discharge) 1=Culvert (Inlet Controls 5.13 cfs @ 3.33 fps)

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 47

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Pond 4P: Revised Center Pond Hydrograph

9.56 cfs

10

Inflow Primary

Inflow Area=7.391 ac Peak Elev=397.03' Storage=0.373 af 24.0" x 12.0" R=12.0" Arch Culvert n=0.015 L=83.0' S=0.0133 '/'

9 8

Flow (cfs)

7 6

5.13 cfs

5 4 3 2 1 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 48

Summary for Pond 5P: South Pond Inflow Area = 4.269 ac, 48.04% Impervious, Inflow Depth > 1.89" for 100-yr event Inflow = 4.13 cfs @ 12.47 hrs, Volume= 0.671 af Outflow = 1.49 cfs @ 13.13 hrs, Volume= 0.666 af, Atten= 64%, Lag= 39.3 min Primary = 1.49 cfs @ 13.13 hrs, Volume= 0.666 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 396.58' @ 13.13 hrs Surf.Area= 0.134 ac Storage= 0.106 af Plug-Flow detention time=44.7 min calculated for 0.666 af (99% of inflow) Center-of-Mass det. time=33.3 min ( 1,338.4 - 1,305.0 ) Volume #1 Elevation (feet) 395.00 397.00 398.00 399.00 400.00 401.00 402.00 403.00

Invert 395.00'

Avail.Storage Storage Description 5.026 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.170 0.322 0.498 0.658 0.862 1.376 2.111

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.170 0.246 0.410 0.578 0.760 1.119 1.743

Cum.Store (acre-feet) 0.000 0.170 0.416 0.826 1.404 2.164 3.283 5.026

Invert Outlet Devices 395.00' 48.0" Round Culvert L= 182.0' RCP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 395.00' / 394.00' S= 0.0055 '/' Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 12.57 sf

Primary OutFlow Max=1.49 cfs @ 13.13 hrs HW=396.58' TW=396.57' (TW follows 0.01' below HW) 1=Culvert (Outlet Controls 1.49 cfs @ 0.48 fps)

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 49

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Pond 5P: South Pond Hydrograph

4.13 cfs

Inflow Primary

4

Inflow Area=4.269 ac Peak Elev=396.58' Storage=0.106 af 48.0" Round Culvert n=0.012 L=182.0' S=0.0055 '/'

Flow (cfs)

3

2

1.49 cfs 1

0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

Post-Development 20260406 NY-Webster extreme precipitation tables 24-hr S0P 100-yr Rainfall=5.16" Printed 4/7/2026 Page 50

Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Link 1L: Site Composite Inflow Area = Inflow = Primary =

19.369 ac, 21.04% Impervious, Inflow Depth > 1.79" for 100-yr event 9.95 cfs @ 13.33 hrs, Volume= 2.888 af 9.95 cfs @ 13.33 hrs, Volume= 2.888 af, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs

Link 1L: Site Composite Hydrograph 11

9.95 cfs

Inflow Primary

10

Inflow Area=19.369 ac

9 8

Flow (cfs)

7 6 5 4 3 2 1 0 0

2

4

6

8

10

12

14

16

18

20

22 24 26 28 Time (hours)

30

32

34

36

38

40

42

44

46

48

1S 1AS

North

North Area Loop Road

1P 3P

Infiltration Trench

North Pond

5S Off-site to North

2S

1L

4P

Site Composite

Revised Center Pond

Center

6S

5P 2P

South Pond

Off-site to Center

Bioretention

4S

2AP

3S Plunge Pool To Bioretention

South

Subcat

Reach

Pond

Link

Routing Diagram for Post-Development 20260406 Prepared by Vanguard Engineering PC, Printed 4/7/2026 HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 2

Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Pond 1P: Infiltration Trench

Peak Elev=400.82' Storage=0.033 af Inflow=3.02 cfs 0.181 af Discarded=0.17 cfs 0.115 af Primary=2.85 cfs 0.066 af Outflow=3.02 cfs 0.180 af

Pond 2AP: Plunge Pool

Peak Elev=401.78' Storage=0.065 af Inflow=12.32 cfs 0.924 af Outflow=12.31 cfs 0.862 af

Pond 2P: Bioretention

Peak Elev=401.76' Storage=0.338 af Inflow=12.31 cfs 0.862 af Outflow=7.59 cfs 0.808 af

Pond 3P: North Pond

Peak Elev=398.89' Storage=0.538 af Inflow=7.55 cfs 1.646 af Outflow=6.21 cfs 1.645 af Peak Elev=397.38' Storage=0.457 af Inflow=12.73 cfs 1.497 af 24.0" x 12.0", R=12.0" Arch Culvert n=0.015 L=83.0' S=0.0133 '/' Outflow=6.92 cfs 1.284 af

Pond 4P: Revised Center Pond Pond 5P: South Pond

Peak Elev=397.04' Storage=0.177 af Inflow=7.71 cfs 0.849 af 48.0" Round Culvert n=0.012 L=182.0' S=0.0055 '/' Outflow=2.26 cfs 0.844 af

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 3

Summary for Pond 1P: Infiltration Trench Inflow Area = 0.487 ac, 82.14% Impervious, Inflow Depth = 4.45" for future 100-yr event Inflow = 3.02 cfs @ 12.04 hrs, Volume= 0.181 af Outflow = 3.02 cfs @ 12.04 hrs, Volume= 0.180 af, Atten= 0%, Lag= 0.0 min Discarded = 0.17 cfs @ 12.04 hrs, Volume= 0.115 af Primary = 2.85 cfs @ 12.04 hrs, Volume= 0.066 af Routed to Pond 3P : North Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 4 Peak Elev= 400.82' @ 12.04 hrs Surf.Area= 0.023 ac Storage= 0.033 af Plug-Flow detention time=50.2 min calculated for 0.180 af (100% of inflow) Center-of-Mass det. time=48.9 min ( 829.8 - 780.9 ) Volume #1

Invert 397.20'

Elevation (feet) 397.20 397.30 400.85

Surf.Area Voids (acres) (%) 0.023 0.0 0.023 40.0 0.023 40.0

Device Routing #1 Primary

#2

Avail.Storage Storage Description 0.034 af Custom Stage Data (Prismatic) Listed below (Recalc)

Discarded

Inc.Store (acre-feet) 0.000 0.001 0.033

Cum.Store (acre-feet) 0.000 0.001 0.034

Invert Outlet Devices 400.80' 505.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 397.20' 5.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.00'

Discarded OutFlow Max=0.17 cfs @ 12.04 hrs HW=400.82' (Free Discharge) 2=Exfiltration ( Controls 0.17 cfs) Primary OutFlow Max=2.62 cfs @ 12.04 hrs HW=400.82' (Free Discharge) 1=Broad-Crested Rectangular Weir (Weir Controls 2.62 cfs @ 0.33 fps)

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 4

Summary for Pond 2AP: Plunge Pool Inflow Area = 2.753 ac, 74.50% Impervious, Inflow Depth = 4.03" for future 100-yr event Inflow = 12.32 cfs @ 12.16 hrs, Volume= 0.924 af Outflow = 12.31 cfs @ 12.16 hrs, Volume= 0.862 af, Atten= 0%, Lag= 0.1 min Primary = 12.31 cfs @ 12.16 hrs, Volume= 0.862 af Routed to Pond 2P : Bioretention Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 401.78' @ 12.16 hrs Surf.Area= 0.047 ac Storage= 0.065 af Flood Elev= 401.90' Surf.Area= 0.049 ac Storage= 0.071 af Plug-Flow detention time=45.0 min calculated for 0.862 af (93% of inflow) Center-of-Mass det. time=11.9 min ( 808.5 - 796.5 ) Volume #1 Elevation (feet) 399.00 401.90

Invert 399.00'

Avail.Storage Storage Description 0.071 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.049

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.071

Cum.Store (acre-feet) 0.000 0.071

Invert Outlet Devices 401.70' 215.0' long + 5.0 '/' SideZ x 3.0' 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 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32

Primary OutFlow Max=12.26 cfs @ 12.16 hrs HW=401.78' (Free Discharge) 1=Broad-Crested Rectangular Weir (Weir Controls 12.26 cfs @ 0.70 fps)

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 5

Summary for Pond 2P: Bioretention [79] Warning: Submerged Pond 2AP Primary device # 1 by 0.06' Inflow Area = 2.753 ac, 74.50% Impervious, Inflow Depth = 3.76" for future 100-yr event Inflow = 12.31 cfs @ 12.16 hrs, Volume= 0.862 af Outflow = 7.59 cfs @ 12.34 hrs, Volume= 0.808 af, Atten= 38%, Lag= 10.7 min Primary = 7.59 cfs @ 12.34 hrs, Volume= 0.808 af Routed to Pond 5P : South Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 401.76' @ 12.34 hrs Surf.Area= 0.185 ac Storage= 0.338 af Flood Elev= 402.30' Surf.Area= 0.190 ac Storage= 0.382 af Plug-Flow detention time=438.7 min calculated for 0.808 af (94% of inflow) Center-of-Mass det. time=407.4 min ( 1,215.9 - 808.5 ) Volume #1

Invert 396.92'

Elevation (feet) 396.92 397.75 400.50 401.50 402.00

Surf.Area Voids (acres) (%) 0.145 0.0 0.145 40.0 0.145 20.0 0.179 100.0 0.190 100.0

Device Routing #1 Primary #2

Avail.Storage Storage Description 0.382 af Custom Stage Data (Prismatic) Listed below (Recalc)

Primary

Inc.Store (acre-feet) 0.000 0.048 0.080 0.162 0.092

Cum.Store (acre-feet) 0.000 0.048 0.128 0.290 0.382

Invert Outlet Devices 396.92' 0.500 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.30' 401.50' 20.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=7.59 cfs @ 12.34 hrs HW=401.76' (Free Discharge) 1=Exfiltration ( Controls 0.15 cfs) 2=Broad-Crested Rectangular Weir (Weir Controls 7.44 cfs @ 1.37 fps)

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 6

Summary for Pond 3P: North Pond Inflow Area = 7.709 ac, 5.19% Impervious, Inflow Depth = 2.56" for future 100-yr event Inflow = 7.55 cfs @ 12.98 hrs, Volume= 1.646 af Outflow = 6.21 cfs @ 13.39 hrs, Volume= 1.645 af, Atten= 18%, Lag= 24.9 min Primary = 6.21 cfs @ 13.39 hrs, Volume= 1.645 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Starting Elev= 397.00' Surf.Area= 0.007 ac Storage= 0.005 af Peak Elev= 398.89' @ 13.39 hrs Surf.Area= 0.507 ac Storage= 0.538 af (0.533 af above start) Flood Elev= 400.00' Surf.Area= 1.560 ac Storage= 1.637 af (1.633 af above start) Plug-Flow detention time=290.2 min calculated for 1.640 af (100% of inflow) Center-of-Mass det. time=286.8 min ( 1,147.4 - 860.5 ) Volume #1

Invert 395.70'

Elevation (feet) 395.70 397.00 398.00 399.00 400.00

Avail.Storage Storage Description 1.637 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.007 0.320 0.529 1.560

Device Routing #1 Primary #2 #3

Device 1 Device 1

#4

Primary

Inc.Store (acre-feet) 0.000 0.005 0.164 0.425 1.045

Cum.Store (acre-feet) 0.000 0.005 0.168 0.593 1.637

Invert Outlet Devices 395.70' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 395.70' / 395.50' S= 0.0077 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf 397.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.50' 24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.90' 10.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=6.21 cfs @ 13.39 hrs HW=398.89' (Free Discharge) 1=Culvert (Inlet Controls 6.21 cfs @ 7.90 fps) 2=Orifice/Grate (Passes < 0.31 cfs potential flow) 3=Orifice/Grate (Passes < 6.47 cfs potential flow) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 7

Summary for Pond 4P: Revised Center Pond Inflow Area = 7.391 ac, 21.97% Impervious, Inflow Depth = 2.43" for future 100-yr event Inflow = 12.73 cfs @ 12.39 hrs, Volume= 1.497 af Outflow = 6.92 cfs @ 12.85 hrs, Volume= 1.284 af, Atten= 46%, Lag= 27.8 min Primary = 6.92 cfs @ 12.85 hrs, Volume= 1.284 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 397.38' @ 12.85 hrs Surf.Area= 0.252 ac Storage= 0.457 af Flood Elev= 399.00' Surf.Area= 0.361 ac Storage= 0.950 af Plug-Flow detention time=104.6 min calculated for 1.284 af (86% of inflow) Center-of-Mass det. time=46.7 min ( 891.9 - 845.1 ) Volume #1 Elevation (feet) 390.60 391.00 392.00 393.00 394.00 395.00 396.00 397.00 398.00 399.00

Invert 390.60'

Avail.Storage Storage Description 0.950 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.004 0.013 0.026 0.044 0.067 0.099 0.227 0.291 0.361

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.001 0.008 0.019 0.035 0.055 0.083 0.163 0.259 0.326

Cum.Store (acre-feet) 0.000 0.001 0.009 0.029 0.064 0.119 0.202 0.365 0.624 0.950

Invert Outlet Devices 396.10' 24.0" W x 12.0" H, R=12.0" Arch Culvert L= 83.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 396.10' / 395.00' S= 0.0133 '/' Cc= 0.900 n= 0.015 Concrete sewer w/manholes & inlets, Flow Area= 1.57 sf

Primary OutFlow Max=6.92 cfs @ 12.85 hrs HW=397.38' (Free Discharge) 1=Culvert (Inlet Controls 6.92 cfs @ 4.41 fps)

Post-Developmen NY-Webster extreme precipitation tables 24-hr S0P 100-yr future 100-yr Rainfall=5.93" Prepared by Vanguard Engineering PC HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Printed 4/7/2026 Page 8

Summary for Pond 5P: South Pond [78] Warning: Submerged Pond 2P Primary device # 1 by 0.12' Inflow Area = 4.269 ac, 48.04% Impervious, Inflow Depth > 2.39" for future 100-yr event Inflow = 7.71 cfs @ 12.34 hrs, Volume= 0.849 af Outflow = 2.26 cfs @ 12.92 hrs, Volume= 0.844 af, Atten= 71%, Lag= 34.9 min Primary = 2.26 cfs @ 12.92 hrs, Volume= 0.844 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 397.04' @ 12.92 hrs Surf.Area= 0.177 ac Storage= 0.177 af Plug-Flow detention time=47.6 min calculated for 0.844 af (99% of inflow) Center-of-Mass det. time=37.8 min ( 1,240.2 - 1,202.4 ) Volume #1 Elevation (feet) 395.00 397.00 398.00 399.00 400.00 401.00 402.00 403.00

Invert 395.00'

Avail.Storage Storage Description 5.026 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.170 0.322 0.498 0.658 0.862 1.376 2.111

Device Routing #1 Primary

Inc.Store (acre-feet) 0.000 0.170 0.246 0.410 0.578 0.760 1.119 1.743

Cum.Store (acre-feet) 0.000 0.170 0.416 0.826 1.404 2.164 3.283 5.026

Invert Outlet Devices 395.00' 48.0" Round Culvert L= 182.0' RCP, end-section conforming to fill, Ke= 0.500 Inlet / Outlet Invert= 395.00' / 394.00' S= 0.0055 '/' Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 12.57 sf

Primary OutFlow Max=2.26 cfs @ 12.92 hrs HW=397.04' TW=397.03' (TW follows 0.01' below HW) 1=Culvert (Outlet Controls 2.26 cfs @ 0.51 fps)

Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series. All precipitation amounts are displayed in inches.

Metadata for Point Smoothing State Location Latitude Longitude Elevation Date/Time

Yes New York New York, United States 43.212 degrees North 77.469 degrees West 120 feet Sun Jul 13 2025 12:52:25 GMT-0400 (Eastern Daylight Time)

15% increase = 2.13

15% increase = 2.48

Extreme Precipitation Estimates 5min 10min 15min 30min 60min 120min

1hr

2hr

3hr

6hr

12hr

24hr

48hr

1day

2day

1yr

0.26

0.40

0.50

0.65

0.81

0.99

1yr

0.70

0.89

1.12

1.34

1.58

1.85

2.06

1yr

1.64

1.99

2yr

0.30

0.47

0.58

0.77

0.97

1.18

2yr

0.83

1.07

1.34

1.59

1.86

2.16

2.42

2yr

1.91

2.32

5yr

0.36

0.56

0.70

0.94

1.20

1.48

5yr

1.04

1.34

1.67

1.98

2.30

2.64

2.98

5yr

2.34

2.86

10yr

0.40

0.63

0.80

1.09

1.42

1.76

10yr

1.22

1.59

1.99

2.34

2.71

3.08

3.49

10yr

2.73

3.35

25yr

0.48

0.76

0.96

1.33

1.77

2.20

25yr

1.52

1.99

2.49

2.92

3.35

3.78

4.30

25yr

3.35

4.13

50yr

0.54

0.87

1.11

1.55

2.09

2.61

50yr

1.80

2.37

2.95

3.45

3.94

4.42

5.04

50yr

3.91

4.85

100yr

0.61

0.99

1.28

1.81

2.47

3.10

100yr

2.13

2.82

3.51

4.09

4.64

5.16

5.91

100yr

4.56

5.68

200yr

0.70

1.14

1.48

2.12

2.93

3.68

200yr

2.53

3.35

4.16

4.83

5.45

6.02

6.93

200yr

5.33

6.67

500yr

0.84

1.38

1.80

2.62

3.67

4.62

500yr

3.16

4.23

5.22

6.02

6.75

7.40

8.56

500yr

6.55

8.23

1day

2day

Lower Confidence Limits

15% increase = 3.54

5min 10min 15min 30min 60min 120min

15% increase = 5.93 1hr

2hr

3hr

6hr

12hr

24hr

48hr

1yr

0.22

0.34

0.42

0.56

0.69

0.77

1yr

0.60

0.75

0.85

1.10

1.41

1.70

1.79

1yr

1.50

1.72

2yr

0.29

0.45

0.56

0.76

0.93

1.04

2yr

0.80

1.02

1.15

1.41

1.71

2.11

2.36

2yr

1.86

2.27

VANGUARD Engineering

PC

Channel Protection Volume (CPv) Calculation

Determine Project Curve Number (CN), Area and Time-of-Concentration (tc): Drainage Basin CN Area (acres) Tc (minutes) 1 61 2.63 20.5 2 59 5.466 28.3 3 89 4 13.8 4 37 1.516 16.87 5 86 0.5 6 6 Weighted CN, Total Area, Longest tc 66.47 14.11 28.3 Initial Abstraction (Ia) = 1.01 (Ia=(200/CN)-2) 1-year Rainfall (P) 1.85 inches Ia/P = 0.55 Time of Concentration (tc) 0.47 hours Unit Peak Discharge (qo) 200 cubic feet per second per square mile (using TR55 Table 4-II) Ratio of Outflow to Inflow (qo/qi) 0.08 24h event (using SMDM Figure 8.5) Runoff Volume (Qd) 0.12 inches Vs/Vr=0.682-1.43(qo/qi)+1.64(qo/qi)2-0.804(qo/qi)3 Vs/Vr = 0.578 Storage Volume (Vs) = CPv = 0.082 acre-feet = 3,553 cubic-feet = (Vs/Vr)(Qd)(A)/12

V:\202511 Dinks and Links SWPPP\reports\SWPPP\SWPPP Channel Protection Volume Calculator 20260317 CPv Calculation 3/20/2026 2:21 PM

V:\202511 Dinks and Links SWPPP\reports\SWPPP\SWPPP Channel Protection Volume Calculator 20260317 CPv Calculation 3/20/2026 2:21 PM

NY-Webster extreme precipitation tables 24-hr S0P 1-yr Rainfall=1.85" Printed 3/20/2026 Prepared by Vanguard Engineering PC

Post-Development 20260317

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Pond 3P: North Pond Inflow Area = 7.630 ac, 5.24% Impervious, Inflow Depth = 0.17" for 1-yr event Inflow = 0.35 cfs @ 13.24 hrs, Volume= 0.106 af Outflow = 0.13 cfs @ 15.38 hrs, Volume= 0.106 af, Atten= 63%, Lag= 128.4 min Primary = 0.13 cfs @ 15.38 hrs, Volume= 0.106 af Routed to Link 1L : Site Composite Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Starting Elev= 397.00' Surf.Area= 0.007 ac Storage= 0.005 af Peak Elev= 397.43' @ 15.38 hrs Surf.Area= 0.141 ac Storage= 0.036 af (0.032 af above start) Flood Elev= 400.00' Surf.Area= 1.560 ac Storage= 1.637 af (1.633 af above start) Plug-Flow detention time=171.3 min calculated for 0.102 af (96% of inflow) Center-of-Mass det. time=134.5 min ( 1,117.9 - 983.4 ) Volume #1

Invert 395.70'

Elevation (feet) 395.70 397.00 398.00 399.00 400.00

Avail.Storage Storage Description 1.637 af Custom Stage Data (Prismatic) Listed below (Recalc)

Surf.Area (acres) 0.000 0.007 0.320 0.529 1.560

Device Routing #1 Primary #2 #3

Device 1 Device 1

#4

Primary

Inc.Store (acre-feet) 0.000 0.005 0.164 0.425 1.045

Cum.Store (acre-feet) 0.000 0.005 0.168 0.593 1.637

Invert Outlet Devices 395.70' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 395.70' / 395.50' S= 0.0077 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf 397.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.50' 24.0" x 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads 398.90' 10.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=0.13 cfs @ 15.38 hrs HW=397.43' (Free Discharge) 1=Culvert (Passes 0.13 cfs of 4.19 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.13 cfs @ 2.65 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

NY-Webster extreme precipitation tables 24-hr S0P 1-yr Rainfall=1.85" Printed 3/20/2026 Prepared by Vanguard Engineering PC

Post-Development 20260317

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Pond 1P: Infiltration Trench Inflow Area = 0.500 ac, 80.00% Impervious, Inflow Depth = 0.74" for 1-yr event Inflow = 0.58 cfs @ 12.05 hrs, Volume= 0.031 af Outflow = 0.13 cfs @ 12.33 hrs, Volume= 0.031 af, Atten= 78%, Lag= 17.0 min Discarded = 0.13 cfs @ 12.33 hrs, Volume= 0.031 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 3P : North Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 398.02' @ 12.33 hrs Surf.Area= 0.023 ac Storage= 0.008 af Plug-Flow detention time=16.2 min calculated for 0.031 af (100% of inflow) Center-of-Mass det. time=16.2 min ( 860.4 - 844.2 ) Volume #1

Invert 397.20'

Elevation (feet) 397.20 397.30 400.85

Surf.Area Voids (acres) (%) 0.023 0.0 0.023 40.0 0.023 40.0

Device Routing #1 Primary

#2

Avail.Storage Storage Description 0.034 af Custom Stage Data (Prismatic) Listed below (Recalc)

Discarded

Inc.Store (acre-feet) 0.000 0.001 0.033

Cum.Store (acre-feet) 0.000 0.001 0.034

Invert Outlet Devices 400.80' 505.0' long x 1.0' 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 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 397.20' 5.000 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.00'

Discarded OutFlow Max=0.13 cfs @ 12.33 hrs HW=398.02' (Free Discharge) 2=Exfiltration ( Controls 0.13 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=397.20' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

NY-Webster extreme precipitation tables 24-hr S0P 1-yr Rainfall=1.85" Printed 3/20/2026 Prepared by Vanguard Engineering PC

Post-Development 20260317

HydroCAD® 10.20-8a s/n 06651 © 2025 HydroCAD Software Solutions LLC

Summary for Pond 2P: Bioretention Inflow Area = 4.000 ac, 84.98% Impervious, Inflow Depth = 0.72" for 1-yr event Inflow = 4.38 cfs @ 12.16 hrs, Volume= 0.240 af Outflow = 0.14 cfs @ 15.82 hrs, Volume= 0.240 af, Atten= 97%, Lag= 219.1 min Primary = 0.14 cfs @ 15.82 hrs, Volume= 0.240 af Routed to Pond 5P : South Pond Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 399.44' @ 15.82 hrs Surf.Area= 0.207 ac Storage= 0.139 af Flood Elev= 402.30' Surf.Area= 0.259 ac Storage= 0.532 af Plug-Flow detention time=504.2 min calculated for 0.240 af (100% of inflow) Center-of-Mass det. time=504.1 min ( 1,376.7 - 872.6 ) Volume #1

Invert 396.92'

Elevation (feet) 396.92 397.75 400.50 401.50 402.00

Surf.Area Voids (acres) (%) 0.207 0.0 0.207 40.0 0.207 20.0 0.241 100.0 0.259 100.0

Device Routing #1 Primary #2

Avail.Storage Storage Description 0.532 af Custom Stage Data (Prismatic) Listed below (Recalc)

Primary

Inc.Store (acre-feet) 0.000 0.069 0.114 0.224 0.125

Cum.Store (acre-feet) 0.000 0.069 0.183 0.407 0.532

Invert Outlet Devices 396.92' 0.500 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 390.30' 401.50' 20.0' long + 3.0 '/' SideZ x 15.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

Primary OutFlow Max=0.14 cfs @ 15.82 hrs HW=399.44' (Free Discharge) 1=Exfiltration ( Controls 0.14 cfs) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

(See attached site drawings)

The construction sequence consists of 8 general steps. Follow the sequence as described on the drawings and as supplemented by this report. Consult the NYS standards and specifications for erosion and sediment control for additional information on specified practices. Step 1: Pre-Construction Resource protection • Developer shall evaluate, mark and protect important trees and associated rooting zones and wetlands. Surface water protection • Protect on-site or downstream surface water subject to disturbed area runoff as shown on drawings. Stabilize construction entrance • Establish temporary construction entrance(s). • Stabilize bare areas (entrances, construction routes, equipment parking areas) immediately as work takes place. The contractor shall top these areas with gravel or maintain vegetative cover. • Remove sediment tracked onto public streets to the satisfaction of inspecting engineer or governing municipality. Continue to remove any sediment tracked throughout the following steps or until site stabilization is established. Perimeter sediment controls • Install silt fence as shown on drawings, or as directed by inspecting engineer or governing municipality. Place silt fence on or parallel to contours where there is no concentrated water flowing. • Install sediment basins as shown on drawings, or as directed by inspecting engineer or governing municipality. Step 2: Runoff and Drainage Control Runoff control • Install remaining erosion and sediment control features. • Divert offsite or clean runoff away from or around disturbed areas. • Convey surface flows from highly erodible soil and steep slopes to more suitable stable areas. • Slow or redirect runoff from existing or proposed cut and fill slopes to lower water velocity. • Ensure site drainage prevents erosion, concentrated flows to adjacent properties, uncontrolled overflow, and ponding. Runoff conveyance system • Stabilize the conveyance system. • Seed channels and stream banks at the outlet points. • Install check dams to slow down the velocity of concentrated flow as shown on the plans, or as directed by the developer. • Protect existing natural drainage systems and streams by maintaining vegetative buffers and by providing the other erosion control features. Step 3: Grading • Commence clearing and earth disturbance after sediment and erosion controls are installed. • Stockpile, protect and stabilize topsoil in a location away from drainage structures and water bodies. • Maintain and do not disturb established buffers, the high-water line of a water body, steep slopes or other protected zones. • Do not impair existing surface drainage that will result in a potential erosion hazard impacting adjacent land or water bodies. • Notify governing municipality and inspecting engineer should they encounter farm tiles during earth moving operations to determine removal, plug or connection to storm system. Step 4: Erosion Control Maintenance and Stabilization • Maintain erosion control features in good working order. • Immediately stabilize site perimeter surfaces.

• • •

Stabilize soil stockpiles and exposed surfaces by seed, mulch or other appropriate measures as soon as possible, but no more than 7 days after construction activity has ceased in that area. Apply temporary or permanent stabilization measures immediately on all disturbed areas where work is delayed or completed. Install additional measures if ordered by governing municipality or inspecting engineer.

Step 5: Sediment Control • Stabilize swales or other areas that transport concentrated flow. • Protect downspout or sump pump discharges with acceptable outfalls such as splash blocks, sod or as directed by inspecting engineer or governing municipality. Step 6: Inspection • Inspect features as indicated on drawings. At a minimum, developer will perform inspections once every 7 calendar days or twice every 7 days should disturbed area meet or exceed 5 acres. • Maintain, repair and/or add erosion and sediment control features as directed by inspecting engineer or governing municipality. • Provide and identify qualified contractor-employed person or hired entities responsible for conducting stormwater management and maintenance actions. • Retain copy of any inspections and SWPPP on-site during construction phase in an accessible but safeguarded location. Step 7: Finalize Grading & Landscaping • Restore all disturbed pervious areas in compliance with NYSDEC stormwater management design manual table 5.3 (shown on this drawing). • Stabilize all open areas, including borrow and spoil areas using permanent topsoil, seed, sod, mulch, riprap or other practice as shown on drawings. • Stabilize site within 7 days after construction activity has ceased or as noted in the SWPPP. • Remove temporary control measures within 7 days after directed by inspecting engineer or governing municipality. Step 8: Post Construction Controls • Developer shall ensure that permanent structural or non-structural practices are properly designed to suit the post-construction site conditions.

CERTIFICATION OF COMPLIANCE WITH FEDERAL, STATE, AND LOCAL REGULATIONS This stormwater pollution prevention plan (SWPPP) reflects State and Federal regulations and requirements for stormwater management and erosion and sediment control. Name (please print): Joseph Ardieta PE Title: President Acting as Professional Engineer or Agent for: Joe Cattalani Signature:

POLLUTION PREVENTION PLAN CERTIFICATION I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that false statements made herein are punishable as a Class A misdemeanor pursuant to Section 210.45 of the Penal Law. Applicant(s) Signature:

Print Name and Title:

Date:

CONTRACTOR’S CERTIFICATION I hereby certify under penalty of law 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 am aware that there are significant penalties for submitting false information that I do not believe to be true, including the possibility of fine and imprisonment for knowing violations. Project:

Dinks and Links

Developer Representative, Title and Company Name:

General Contractor

Name, Address, Phone and Trained Employee Name

Signature

______________________________________________

_________________________________

______________________________________________

______________________________________________

______________________________________________

Landscape Contractor Signature

______________________________________________

_________________________________

______________________________________________

______________________________________________

______________________________________________

Underground Utilities Signature

______________________________________________

_________________________________

______________________________________________

______________________________________________

______________________________________________

Long Term Maintenance Plan Storm water management practices shall be properly maintained to ensure they operate correctly and provide the water quality treatment for which they were designed. Routine maintenance performed on a frequently scheduled basis, can help avoid more costly rehabilitative maintenance that results when practices are not adequately maintained. A. Maintenance Categories Storm water management practice (SMP) maintenance programs are separated into three broad categories of work. These categories are based largely on the Urban Drainage and Flood Control District’s Maintenance Program for regional drainage practices. The categories are separated based upon the magnitude and type of the maintenance activities performed. A description of each category follows: 1. Routine Work The majority of this work consists of scheduled mowing and debris pickup for storm water management practices during the growing season. This includes items such as the removal of debris/material that may be clogging the outlet structure and/or trash rack. It also includes activities such as weed control and algae treatment. These activities normally will be performed as needed during the year. However, they must be performed at least on a monthly basis from March to November and at least once from December to February. These items can be completed without prior correspondence with the jurisdictional municipality. However, the owner must complete an Inspection and Maintenance Report for each occurrence. Owner shall supply all reports to the jurisdictional municipality annually. 2. Restoration Work This work consists of small-scale maintenance and/or work needed to address operational problems. Most of this work can be completed by a small crew, with minor tools, and small equipment. Owner shall correspond with the jurisdictional municipality prior to commencing such work by submitting written description of each maintenance activity. 3. Rehabilitation Work This work consists of large-scale maintenance and major improvements needed to address failures within the storm water management practices. This work requires prior consultation with the jurisdictional municipality and may require an engineering design with prepared construction plans for review and approval. This work may also require specialized maintenance equipment, surveying, construction permits or assistance through private contractors and consultants. If these items are needed, the Owner shall submit written description of maintenance issue and proposed resolution for each maintenance activity. 4. Sediment Removal Owner shall remove sediment in the deep pool every 5 years or after accumulation reaches 50% of deep pool volume. B. Maintenance Personnel Owner’s maintenance personnel shall be qualified to properly maintain storm water management practices. Inadequately trained personnel can cause additional problems resulting in additional maintenance costs. C. Maintenance Forms The Storm water Management Practice Inspection and Maintenance Report provides a record of SMP review and maintenance activities. Owner or designated personnel shall complete Reports. Reports shall be submitted annually to the jurisdictional municipality. The Owner accepts all responsibility for completed formwork submitted to jurisdictional municipality. Owner shall use the attached Storm water Management Practice Inspection and Maintenance Report.