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HomeMy WebLinkAboutTaco Bell Stormwater Management Report 01.15.26 Stormwater Management Report 433, 437, & 439 Station Avenue Yarmouth, MA 02664 Submitted: 1/15/2026 Prepared For: Desert De Oro Foods, Inc. 79 Main Street Mansfield, MA 02048 Proposed Taco Bell Desert De Oro Foods, Inc. 79 Main Street Mansfield, Massachusetts 02048 Section 1 - Introduction Section 2 - Existing Site conditions Section 3 - Proposed Development Section 4 - Stormwater Standards and Compliance Appendix A: Precipitation Data Appendix B: NRCS Websoil Survey Appendix C: HydroCAD Report Appendix D: Pre-Development and Post-Development Watershed Plans Appendix E: Post-Development Stormwater Inspection & Maintenance Manual Appendix A: Precipitation Data Stormwater Management Report Tax Map 88 Lot(s) 87 & 88 Yarmouth, Massachusetts Prepared for: Desert De Oro Foods, Inc. 79 Main Street Mansfield, Ma 02048 SECTION 1 - INTRODUCTION McClure Engineering Company (McClure) has prepared this Stormwater Management Report for the redevelopment of the properties located at 433 and 439 Station Avenue in Yarmouth, Massachusetts. The report is related to the proposed redevelopment to include a fast-food restaurant and related site improvements. The applicant is proposing the construction of a single fast-food restaurant building with drive-thru service, parking, vehicle and pedestrian circulation routes, and associated stormwater and utility improvements. The site is served by municipal water, gas, electricity, communications, and an on- site septic system. The purpose of this report is to analyze the qualitative and quantitative impacts of the proposed development as it relates to local and state regulatory requirements for stormwater management. The project disturbs less than one (1) acre of land and is not located within or adjacent to jurisdictional resource areas. As such, the redevelopment project is not subject to the Massachusetts Department of Environmental Protection (MassDEP) Stormwater Standards or the Town of Yarmouth Conservation Commission Stormwater Management Regulations. However, the project has been designed to comply with the Stormwater Standards and local regulations to the extent practicable. The objective of the proposed stormwater management system is to support a functional site development and comply with the Town of Yarmouth Stormwater Management Regulations as well as the Massachusetts Stormwater Handbook to the greatest extent possible. The report will demonstrate that the proposed redevelopment results in a reduction of total impervious areas and peak rates of stormwater runoff, and that the proposed stormwater management system complies with the ten (10) stormwater standards put forth by the Massachusetts Department of Environmental Protection (MassDEP). SECTION 2 – EXISTING CONDITIONS The project site is occupied by a gas station/service center and a commercial building. The 0.86 acre lot contains paved parking areas, buildings, small grassed areas, and utilities. Access to the site is provided via five (5) existing driveways located along Old Town House Road as well as Station Avenue. According to the U.S. Department of Agriculture (USDA), Natural Resources Conservation Service Stormwater Management Report McClure Proposed Taco Bell Restaurant 10/10/2025 P a g e 2 of 6 (NRCS) Web Soil Survey, on-site soils are mainly composed of Carver Course Sand, which is classified as Hydrologic Soil Group (HSG) A. Topography of the site is primarily flat and slopes towards both Old Townhouse Road and Station Avenue. The existing stormwater system consists of leaching catch basins. All stormwater that is not conveyed to one of the leaching catch basin locations flows overland into the municipal systems on both Old Town House Road and Station Avenue. Within the project location, there are no jurisdictional wetland resource areas or environmentally sensitive zones such as Outstanding Resource Waters (ORW), Areas of Critical Environmental Concern (ACEC), or Natural Heritage & Endangered Species Program (NHESP) Priority and Protected Habitat for rare and endangered species. The project location does fall within a Wellhead Protection Area Zone II. As such, appropriate stormwater management BMP’s were selected for the site given its location within the Zone II. In order to compare the pre-development and post-development conditions of the site, existing and proposed watershed subcatchments have been identified, along with design points for analysis and comparison of peak flows resulting from the site. In the existing conditions, a total of ten (10) subcatchments with six (6) observation/analysis points were identified. Refer to the Appendix for the Pre-Development Watershed Plan. SECTION 3 – PROPOSED DEVELOPMENT The applicant is proposing the construction of a single fast-food restaurant, landscaping, lighting, parking, vehicle and pedestrian routes, associated stormwater and utility improvements. The site has a disturbed area of approximately 0.85 acres, with 0.54 acres of this area proposed to be impervious surface, representing an overall reduction in impervious area. Stormwater runoff from the site will be captured via catch basins, roof drains, and a trench drain and conveyed into an underground infiltration system consisting of prefabricated stormwater chambers. The function of the underground chamber system is to provide stormwater storage and promote infiltration into the subsurface sandy soils. Through use of this system, the project will promote groundwater recharge through infiltration and will reduce peak rates of runoff from the site. The proposed development results in an improvement to the site in comparison to the existing condition because of reduced impervious area, infiltration, and peak flow reduction. In the proposed condition, a total of ten (10) subcatchments with six (6) observation/analysis points were identified. Refer to the Appendix for the Post-Development Watershed Plan. SECTION 4 – STORMWATER STANDARDS AND COMPLIANCE The quantity of runoff and the conveyance of that flow through the site are determined using the software package HydroCAD 10.20-2d by HydroCAD Software Solutions LLC. HydroCAD is a computer aided design program for modeling stormwater hydrology based on the Soil Conservation Service (SCS) TR- 55 method combined with standard hydraulics calculations. Stormwater Management Report McClure Proposed Taco Bell Restaurant 10/10/2025 P a g e 3 of 6 The project is not subject to the Town of Yarmouth Conservation Commission Stormwater Management Regulations or the Massachusetts Stormwater Standards due to the proposed land disturbance totaling less than one (1) acre, and the lack of any adjacent areas subject to the Wetlands Protection Act. However, the project has been designed for compliance to the greatest extent possible. This section describes the project’s compliance with the applicable stormwater standards. MassDEP Standards Standard 1 No new stormwater conveyances (e.g. outfalls) may discharge untreated stormwater directly untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. The proposed redevelopment will not convey any untreated stormwater or cause any erosion in wetlands or waters of the Commonwealth. The site does not propose any surface discharges of stormwater. All discharges will be below-grade through infiltration. Therefore, discharges will not cause erosion in wetland or waters of the Commonwealth. Standard 2 Stormwater management systems shall be designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates. This standard may be waived for discharges to land subject to coastal storm flowage as defined in 310 CMR 10.04. The proposed redevelopment has been designed such that the post-development discharge rates do not exceed the pre-development discharge rates. Calculations have been provided to show that the proposed development runoff rates do not excees those in the pre-development condition. This is achieved through the use of stormwater detention and infiltration within the subsurface chamber system. Refer to Table 1.1. A HydroCAD report is included in the Appendix. Standard 3 Loss of annual recharge to groundwater shall be eliminated or minimized through the use of environmentally sensitive site design, low impact development techniques, stormwater best management practices, and good operation and maintenance. At a minimum, the annual recharge from the post- development site shall approximate the annual recharge from pre-development conditions based on soil type. This Standard is met when the stormwater management system is designed to infiltrate the required recharge volume as determined in accordance with the Massachusetts Stormwater Handbook. The redeveloped condition of the site includes approximately 23,697 square feet (sf) of impervious area which is a decrease from the 30,840 sf of impervious area in the pre-developed site condition. Runoff from the proposed development will be collected by the proposed closed drainage system on the property and conveyed into the underground infiltration chamber system. Rv=(Target Depth Factor)x(Impervious Area) Rv=(0.6/12in)x(0.544 acres) Rv=1,184 cubic feet Stormwater Management Report McClure Proposed Taco Bell Restaurant 10/10/2025 P a g e 4 of 6 The proposed chamber system provides 5,145 cubic feet of storage, which exceeds the required recharge volume. Standard 4 Stormwater management systems shall be designed to remove 80% of the average annual post- construction load of Total Suspended Solids (TSS). This standard is met when: a) Suitable practices for source control and pollution prevention are identified in a long-term pollution prevention plan, and thereafter are implemented and maintained; b) Structural stormwater best management practices are sized to capture the required water quality volume as determined in accordance with the Massachusetts Stormwater Handbook; and c) Pretreatment is provided in accordance with the Massachusetts Stormwater Handbook. The proposed development utilizes an Stormtech Chamber system which has a Stormtech Isolator Row pretreatment system built in. This system meets the 80% TSS removal standard and the 44% pretreatments TSS removal requirements, due to the location with the Zone II. In compliance with the Stormwater Handbook, a 1” water quality depth is used for the water quality volume calculation based on the location within the Zone II. Vwq=(1 in/12inch/ft)x(0.544 acres*43560 s.f/acre) Vwq=1,975 cubic feet The required water volume is 1,975 cubic feet, the proposed chamber system, which fully infiltrates, has a total storage of 5,145 cubic feet which exceeds this requirement. Standard 5 For land uses with higher potential pollutant loads, source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable. If, through source control and/or pollution prevention, all land uses with higher potential pollutant loads cannot be completely protected from exposure to rain, snow, snow melt and stormwater runoff, the proponent shall use the specific structural stormwater BMPs determined by the Department to be suitable for such uses as provided in the Massachusetts Stormwater Handbook. Stormwater discharges from land uses with higher potential pollutant loads shall also comply with the requirements of the Massachusetts Clean Waters Act, M.G.L.c. 21, §§ 26-53 and the regulations promulgated thereunder at 314 CMR 3.00, 314 CMR 4.00 and 314 CMR 5.00. The proposed development is not a LUHPPL. Standard 6 Stormwater discharges within the Zone II or Interim Wellhead Protection Area of a public water supply and stormwater discharges near or to any other critical area require the use of the specific source control and pollution prevention measures and the specific structural stormwater best management practices determined by the Department to be suitable for managing discharges to such areas, as Stormwater Management Report McClure Proposed Taco Bell Restaurant 10/10/2025 P a g e 5 of 6 provided in the Massachusetts Stormwater Handbook. A discharge is near a critical area if there is a strong likelihood of a significant impact occurring to said area, taking into account site-specific factors. Stormwater discharges to Outstanding Resource Waters and Special Resource Waters shall be removed and set back from the receiving water or wetland and receive the highest and best practical method of treatment. A “storm water discharge” as defined in 314 CMR 3.04(2)(a)1. or (b) to an Outstanding Resource Water or Special Resource Water shall comply with 314 CMR 3.00 and 314 CMR 4.00. 1 Stormwater discharges to a Zone I or Zone A are prohibited unless essential to the operation of the public water supply. The proposed development is located within a Wellhead Protection Area Zone II which is associated with the Public Water Supply Well 4351000-11G which is associated with the Yarmouth Water Department. The site proposes the installation of deep sump catch basins (25% TSS Removal) along with a Stormtech Isolator Row (>80% TSS Removal) Prior to infiltration which meets the 44% TSS removal prior to infiltration requirement. Standard 7 A redevelopment project is required to meet the following Stormwater Management Standards only to the maximum extent practicable: Standard 2, Standard 3, and the pretreatment and structural stormwater best management practice requirements of Standards 4, 5, and 6. Existing stormwater discharges shall comply with Standard 1 only to the maximum extent practicable. A redevelopment project shall also comply with all other requirements of the Stormwater Management Standards and improve existing conditions. The proposed development is a redevelopment project and meets standards 2, 3, 4, 5, and 6 to the greatest extent possible through the use of erosion controls, pretreatment, and a subsurface infiltration system. Standard 8 A plan to control construction-related impacts, including erosion, sedimentation, and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention plan) shall be developed and implemented. An erosion and sedimentation control plan has been developed to control construction-related impacts. A Stormwater Pollution Prevention Plan (SWPPP) will be prepared and submitted prior to the start of construction. Standard 9 A Long -Term Operation and Maintenance (O&M) Plan shall be developed and implemented to ensure that stormwater management systems function as designed. An Operation and Maintenance Manual has been prepared as part of this Stormwater Management Report. Refer to the Appendix for the Operation and Maintenance Manual. Stormwater Management Report McClure Proposed Taco Bell Restaurant 10/10/2025 P a g e 6 of 6 Standard 10 All illicit discharges to the stormwater management system are prohibited. There are no expected illicit discharges to the stormwater management system. An Illicit Discharge Compliance Statement will be prepared and submitted prior to the discharge of stormwater runoff to the proposed stormwater management practices. Town of Yarmouth Site Plan Review Section 103.3.1.5 Drainage serving the site must comply with Section 304 – Stormwater Management The proposed development does not need to comply with Section 103.3.1.5 as the proposed development results in below one-acre of land disturbance as outlined in section 2.02 in the Town of Yarmouth Stormwater Management Regulations. However, the project was designed to comply with the regulations given that full compliance with the MassDEP Stormwater Handbook is achieved with the design. Table 1.1: Peak Flow Rates (CFS) to Observation Points Location Q2-YR (CFS) Q10-YR (CFS) Q25-YR (CFS) Q50-YR (CFS) Pre Post ∆ Pre Post ∆ Pre Post ∆ Pre Post ∆ OP-1 0.13 0.00 -0.13 0.19 0.00 -0.19 0.23 0.00 -0.23 0.28 0.00 -0.28 OP-2 0.07 0.00 -0.07 0.17 0.00 -0.17 0.25 0.01 -0.24 0.33 0.02 -0.31 OP-3 0.63 0.00 -0.63 1.07 0.00 -1.07 1.41 0.00 -1.41 1.73 0.00 -1.73 OP-4 0.26 0.00 -0.26 0.43 0.00 -0.43 0.59 0.00 -0.59 0.73 0.00 -0.73 OP-5 0.33 0.00 -0.33 0.57 0.00 -0.57 0.76 0.00 -0.76 0.93 0.01 -0.92 OP-6 0.37 0.00 -0.37 0.55 0.01 -0.54 0.69 0.04 -0.65 0.81 0.11 -0.70 Table 1.2: Peak Volumes (AF) to Observation Points Location V50-YR (AF) Pre Post ∆ OP-1 0.022 0.000 -0.022 OP-2 0.023 0.003 -0.020 OP-3 0.128 0.000 -0.128 OP-4 0.058 0.000 -0.058 OP-5 0.068 0.001 -0.067 OP-6 0.065 0.013 -0.052 Appendix B: NRCS Websoil Survey Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/2/2025 Page 1 of 44615310461534046153704615400461543046154604615490461552046153104615340461537046154004615430461546046154904615520399340399370399400399430399460399490399520399550399580399610399640399670 399340 399370 399400 399430 399460 399490 399520 399550 399580 399610 399640 399670 41° 41' 6'' N 70° 12' 34'' W41° 41' 6'' N70° 12' 19'' W41° 40' 59'' N 70° 12' 34'' W41° 40' 59'' N 70° 12' 19'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84 0 50 100 200 300 Feet 0 20 40 80 120 Meters Map Scale: 1:1,620 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION 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 A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:25,000. Warning: Soil Map may not be valid at this scale. 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. 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. Soil Survey Area: Barnstable County, Massachusetts Survey Area Data: Version 23, Sep 17, 2024 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 10, 2022—Jun 30, 2022 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. Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/2/2025 Page 2 of 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 252A Carver coarse sand, 0 to 3 percent slopes A 10.6 100.0% Totals for Area of Interest 10.6 100.0% 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. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/2/2025 Page 3 of 4 Tie-break Rule: Higher Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/2/2025 Page 4 of 4 Appendix C: HydroCAD Report 1S EX-2 2S EX-3 3S EX-4 4S EX-5 5S EX-6 6S EX-7 7S EX-8 EX-1 EX-1 OP-1 NORTHERN LEACHING CATCH BASIN (OP-1) OP-2 NORTHWEST LOT LINE (88-89) OP-3 SOUTHERN CB (OLD TOWNHOUSE ROAD) OP-4 NORTHEAST LEACHING CB (STATION AVE) OP-5 OLD TOWNHOUSE ROAD OP-6 STATION AVE Routing Diagram for 25-0275EX00 Prepared by McClure, Printed 10/8/2025 HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Subcat Reach Pond Link Pre-Developed Conditions 25-0275EX00 Printed 10/8/2025Prepared by McClure Page 2HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.148 39 >75% Grass cover, Good, HSG A (1S, 2S, 3S, 4S, 5S, 6S, 7S, EX-1) 0.175 76 Gravel roads, HSG A (2S, 4S, 5S, 6S) 0.366 98 Paved parking, HSG A (1S, 2S, 3S, 4S, 6S, 7S, EX-1) 0.167 98 Roofs, HSG A (1S, 2S, 3S, 5S, 6S, EX-1) 0.856 83 TOTAL AREA Pre-Developed Conditions 25-0275EX00 Printed 10/8/2025Prepared by McClure Page 3HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.856 HSG A 1S, 2S, 3S, 4S, 5S, 6S, 7S, EX-1 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 0.856 TOTAL AREA Pre-Developed Conditions 25-0275EX00 Printed 10/8/2025Prepared by McClure Page 4HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.148 0.000 0.000 0.000 0.000 0.148 >75% Grass cover, Good 1S, 2S, 3S, 4S, 5S, 6S, 7S, EX-1 0.175 0.000 0.000 0.000 0.000 0.175 Gravel roads 2S, 4S, 5S, 6S 0.366 0.000 0.000 0.000 0.000 0.366 Paved parking 1S, 2S, 3S, 4S, 6S, 7S, EX-1 0.167 0.000 0.000 0.000 0.000 0.167 Roofs 1S, 2S, 3S, 5S, 6S, EX-1 0.856 0.000 0.000 0.000 0.000 0.856 TOTAL AREA Pre-Developed Conditions Type III 24-hr 2-yr Rainfall=3.27"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 5HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3,284 sf 53.50% Impervious Runoff Depth=0.92"Subcatchment 1S: EX-2 Flow Length=54' Slope=0.0022 '/' Tc=6.0 min CN=71 Runoff=0.07 cfs 0.006 af Runoff Area=12,340 sf 64.17% Impervious Runoff Depth=1.90"Subcatchment 2S: EX-3 Flow Length=152' Tc=6.0 min CN=86 Runoff=0.63 cfs 0.045 af Runoff Area=3,627 sf 96.25% Impervious Runoff Depth=2.82"Subcatchment 3S: EX-4 Flow Length=81' Slope=0.0204 '/' Tc=6.0 min CN=96 Runoff=0.26 cfs 0.020 af Runoff Area=3,412 sf 4.81% Impervious Runoff Depth=0.24"Subcatchment 4S: EX-5 Flow Length=99' Slope=0.0288 '/' Tc=6.0 min CN=54 Runoff=0.01 cfs 0.002 af Runoff Area=6,798 sf 46.93% Impervious Runoff Depth=1.82"Subcatchment 5S: EX-6 Flow Length=76' Slope=0.0276 '/' Tc=6.0 min CN=85 Runoff=0.33 cfs 0.024 af Runoff Area=5,223 sf 95.14% Impervious Runoff Depth=2.82"Subcatchment 6S: EX-7 Flow Length=64' Slope=0.0135 '/' Tc=6.0 min CN=96 Runoff=0.37 cfs 0.028 af Runoff Area=849 sf 3.53% Impervious Runoff Depth=0.01"Subcatchment 7S: EX-8 Flow Length=14' Slope=0.0162 '/' Tc=6.0 min CN=41 Runoff=0.00 cfs 0.000 af Runoff Area=1,774 sf 96.00% Impervious Runoff Depth=2.82"Subcatchment EX-1: EX-1 Flow Length=57' Slope=0.0360 '/' Tc=6.0 min CN=96 Runoff=0.13 cfs 0.010 af Inflow=0.13 cfs 0.010 afReach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) Outflow=0.13 cfs 0.010 af Inflow=0.07 cfs 0.006 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.07 cfs 0.006 af Inflow=0.63 cfs 0.045 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=0.63 cfs 0.045 af Inflow=0.26 cfs 0.021 afReach OP-4: NORTHEAST LEACHING CB (STATION AVE) Outflow=0.26 cfs 0.021 af Inflow=0.33 cfs 0.024 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.33 cfs 0.024 af Inflow=0.37 cfs 0.028 afReach OP-6: STATION AVE Outflow=0.37 cfs 0.028 af Total Runoff Area = 0.856 ac Runoff Volume = 0.133 af Average Runoff Depth = 1.86" 37.75% Pervious = 0.323 ac 62.25% Impervious = 0.533 ac Pre-Developed Conditions Type III 24-hr 10-yr Rainfall=4.77"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 6HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3,284 sf 53.50% Impervious Runoff Depth=1.94"Subcatchment 1S: EX-2 Flow Length=54' Slope=0.0022 '/' Tc=6.0 min CN=71 Runoff=0.17 cfs 0.012 af Runoff Area=12,340 sf 64.17% Impervious Runoff Depth=3.25"Subcatchment 2S: EX-3 Flow Length=152' Tc=6.0 min CN=86 Runoff=1.07 cfs 0.077 af Runoff Area=3,627 sf 96.25% Impervious Runoff Depth=4.30"Subcatchment 3S: EX-4 Flow Length=81' Slope=0.0204 '/' Tc=6.0 min CN=96 Runoff=0.38 cfs 0.030 af Runoff Area=3,412 sf 4.81% Impervious Runoff Depth=0.81"Subcatchment 4S: EX-5 Flow Length=99' Slope=0.0288 '/' Tc=6.0 min CN=54 Runoff=0.05 cfs 0.005 af Runoff Area=6,798 sf 46.93% Impervious Runoff Depth=3.16"Subcatchment 5S: EX-6 Flow Length=76' Slope=0.0276 '/' Tc=6.0 min CN=85 Runoff=0.57 cfs 0.041 af Runoff Area=5,223 sf 95.14% Impervious Runoff Depth=4.30"Subcatchment 6S: EX-7 Flow Length=64' Slope=0.0135 '/' Tc=6.0 min CN=96 Runoff=0.55 cfs 0.043 af Runoff Area=849 sf 3.53% Impervious Runoff Depth=0.22"Subcatchment 7S: EX-8 Flow Length=14' Slope=0.0162 '/' Tc=6.0 min CN=41 Runoff=0.00 cfs 0.000 af Runoff Area=1,774 sf 96.00% Impervious Runoff Depth=4.30"Subcatchment EX-1: EX-1 Flow Length=57' Slope=0.0360 '/' Tc=6.0 min CN=96 Runoff=0.19 cfs 0.015 af Inflow=0.19 cfs 0.015 afReach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) Outflow=0.19 cfs 0.015 af Inflow=0.17 cfs 0.012 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.17 cfs 0.012 af Inflow=1.07 cfs 0.077 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=1.07 cfs 0.077 af Inflow=0.43 cfs 0.035 afReach OP-4: NORTHEAST LEACHING CB (STATION AVE) Outflow=0.43 cfs 0.035 af Inflow=0.57 cfs 0.041 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.57 cfs 0.041 af Inflow=0.55 cfs 0.043 afReach OP-6: STATION AVE Outflow=0.55 cfs 0.043 af Total Runoff Area = 0.856 ac Runoff Volume = 0.223 af Average Runoff Depth = 3.13" 37.75% Pervious = 0.323 ac 62.25% Impervious = 0.533 ac Pre-Developed Conditions Type III 24-hr 25-yr Rainfall=5.92"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 7HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3,284 sf 53.50% Impervious Runoff Depth=2.83"Subcatchment 1S: EX-2 Flow Length=54' Slope=0.0022 '/' Tc=6.0 min CN=71 Runoff=0.25 cfs 0.018 af Runoff Area=12,340 sf 64.17% Impervious Runoff Depth=4.33"Subcatchment 2S: EX-3 Flow Length=152' Tc=6.0 min CN=86 Runoff=1.41 cfs 0.102 af Runoff Area=3,627 sf 96.25% Impervious Runoff Depth=5.45"Subcatchment 3S: EX-4 Flow Length=81' Slope=0.0204 '/' Tc=6.0 min CN=96 Runoff=0.48 cfs 0.038 af Runoff Area=3,412 sf 4.81% Impervious Runoff Depth=1.40"Subcatchment 4S: EX-5 Flow Length=99' Slope=0.0288 '/' Tc=6.0 min CN=54 Runoff=0.11 cfs 0.009 af Runoff Area=6,798 sf 46.93% Impervious Runoff Depth=4.23"Subcatchment 5S: EX-6 Flow Length=76' Slope=0.0276 '/' Tc=6.0 min CN=85 Runoff=0.76 cfs 0.055 af Runoff Area=5,223 sf 95.14% Impervious Runoff Depth=5.45"Subcatchment 6S: EX-7 Flow Length=64' Slope=0.0135 '/' Tc=6.0 min CN=96 Runoff=0.69 cfs 0.054 af Runoff Area=849 sf 3.53% Impervious Runoff Depth=0.53"Subcatchment 7S: EX-8 Flow Length=14' Slope=0.0162 '/' Tc=6.0 min CN=41 Runoff=0.00 cfs 0.001 af Runoff Area=1,774 sf 96.00% Impervious Runoff Depth=5.45"Subcatchment EX-1: EX-1 Flow Length=57' Slope=0.0360 '/' Tc=6.0 min CN=96 Runoff=0.23 cfs 0.018 af Inflow=0.23 cfs 0.018 afReach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) Outflow=0.23 cfs 0.018 af Inflow=0.25 cfs 0.018 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.25 cfs 0.018 af Inflow=1.41 cfs 0.103 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=1.41 cfs 0.103 af Inflow=0.59 cfs 0.047 afReach OP-4: NORTHEAST LEACHING CB (STATION AVE) Outflow=0.59 cfs 0.047 af Inflow=0.76 cfs 0.055 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.76 cfs 0.055 af Inflow=0.69 cfs 0.054 afReach OP-6: STATION AVE Outflow=0.69 cfs 0.054 af Total Runoff Area = 0.856 ac Runoff Volume = 0.296 af Average Runoff Depth = 4.14" 37.75% Pervious = 0.323 ac 62.25% Impervious = 0.533 ac Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 8HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3,284 sf 53.50% Impervious Runoff Depth=3.71"Subcatchment 1S: EX-2 Flow Length=54' Slope=0.0022 '/' Tc=6.0 min CN=71 Runoff=0.33 cfs 0.023 af Runoff Area=12,340 sf 64.17% Impervious Runoff Depth=5.35"Subcatchment 2S: EX-3 Flow Length=152' Tc=6.0 min CN=86 Runoff=1.72 cfs 0.126 af Runoff Area=3,627 sf 96.25% Impervious Runoff Depth=6.50"Subcatchment 3S: EX-4 Flow Length=81' Slope=0.0204 '/' Tc=6.0 min CN=96 Runoff=0.57 cfs 0.045 af Runoff Area=3,412 sf 4.81% Impervious Runoff Depth=2.02"Subcatchment 4S: EX-5 Flow Length=99' Slope=0.0288 '/' Tc=6.0 min CN=54 Runoff=0.17 cfs 0.013 af Runoff Area=6,798 sf 46.93% Impervious Runoff Depth=5.23"Subcatchment 5S: EX-6 Flow Length=76' Slope=0.0276 '/' Tc=6.0 min CN=85 Runoff=0.93 cfs 0.068 af Runoff Area=5,223 sf 95.14% Impervious Runoff Depth=6.50"Subcatchment 6S: EX-7 Flow Length=64' Slope=0.0135 '/' Tc=6.0 min CN=96 Runoff=0.81 cfs 0.065 af Runoff Area=849 sf 3.53% Impervious Runoff Depth=0.91"Subcatchment 7S: EX-8 Flow Length=14' Slope=0.0162 '/' Tc=6.0 min CN=41 Runoff=0.01 cfs 0.001 af Runoff Area=1,774 sf 96.00% Impervious Runoff Depth=6.50"Subcatchment EX-1: EX-1 Flow Length=57' Slope=0.0360 '/' Tc=6.0 min CN=96 Runoff=0.28 cfs 0.022 af Inflow=0.28 cfs 0.022 afReach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) Outflow=0.28 cfs 0.022 af Inflow=0.33 cfs 0.023 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.33 cfs 0.023 af Inflow=1.73 cfs 0.128 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=1.73 cfs 0.128 af Inflow=0.73 cfs 0.058 afReach OP-4: NORTHEAST LEACHING CB (STATION AVE) Outflow=0.73 cfs 0.058 af Inflow=0.93 cfs 0.068 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.93 cfs 0.068 af Inflow=0.81 cfs 0.065 afReach OP-6: STATION AVE Outflow=0.81 cfs 0.065 af Total Runoff Area = 0.856 ac Runoff Volume = 0.364 af Average Runoff Depth = 5.11" 37.75% Pervious = 0.323 ac 62.25% Impervious = 0.533 ac Pre-Developed Conditions Type III 24-hr 100-yr Rainfall=8.23"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 9HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=3,284 sf 53.50% Impervious Runoff Depth=4.78"Subcatchment 1S: EX-2 Flow Length=54' Slope=0.0022 '/' Tc=6.0 min CN=71 Runoff=0.42 cfs 0.030 af Runoff Area=12,340 sf 64.17% Impervious Runoff Depth=6.55"Subcatchment 2S: EX-3 Flow Length=152' Tc=6.0 min CN=86 Runoff=2.08 cfs 0.155 af Runoff Area=3,627 sf 96.25% Impervious Runoff Depth=7.75"Subcatchment 3S: EX-4 Flow Length=81' Slope=0.0204 '/' Tc=6.0 min CN=96 Runoff=0.67 cfs 0.054 af Runoff Area=3,412 sf 4.81% Impervious Runoff Depth=2.83"Subcatchment 4S: EX-5 Flow Length=99' Slope=0.0288 '/' Tc=6.0 min CN=54 Runoff=0.25 cfs 0.018 af Runoff Area=6,798 sf 46.93% Impervious Runoff Depth=6.44"Subcatchment 5S: EX-6 Flow Length=76' Slope=0.0276 '/' Tc=6.0 min CN=85 Runoff=1.13 cfs 0.084 af Runoff Area=5,223 sf 95.14% Impervious Runoff Depth=7.75"Subcatchment 6S: EX-7 Flow Length=64' Slope=0.0135 '/' Tc=6.0 min CN=96 Runoff=0.96 cfs 0.077 af Runoff Area=849 sf 3.53% Impervious Runoff Depth=1.45"Subcatchment 7S: EX-8 Flow Length=14' Slope=0.0162 '/' Tc=6.0 min CN=41 Runoff=0.02 cfs 0.002 af Runoff Area=1,774 sf 96.00% Impervious Runoff Depth=7.75"Subcatchment EX-1: EX-1 Flow Length=57' Slope=0.0360 '/' Tc=6.0 min CN=96 Runoff=0.33 cfs 0.026 af Inflow=0.33 cfs 0.026 afReach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) Outflow=0.33 cfs 0.026 af Inflow=0.42 cfs 0.030 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.42 cfs 0.030 af Inflow=2.11 cfs 0.157 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=2.11 cfs 0.157 af Inflow=0.92 cfs 0.072 afReach OP-4: NORTHEAST LEACHING CB (STATION AVE) Outflow=0.92 cfs 0.072 af Inflow=1.13 cfs 0.084 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=1.13 cfs 0.084 af Inflow=0.96 cfs 0.077 afReach OP-6: STATION AVE Outflow=0.96 cfs 0.077 af Total Runoff Area = 0.856 ac Runoff Volume = 0.447 af Average Runoff Depth = 6.26" 37.75% Pervious = 0.323 ac 62.25% Impervious = 0.533 ac Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 1HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: EX-2 Runoff = 0.33 cfs @ 12.09 hrs, Volume= 0.023 af, Depth= 3.71" Routed to Reach OP-2 : NORTHWEST LOT LINE (88-89) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 1,527 39 >75% Grass cover, Good, HSG A 30 98 Paved parking, HSG A 1,727 98 Roofs, HSG A 3,284 71 Weighted Average 1,527 46.50% Pervious Area 1,757 53.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 54 0.0022 0.54 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 1.7 54 Total, Increased to minimum Tc = 6.0 min Subcatchment 1S: EX-2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.36 0.34 0.32 0.3 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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=3,284 sf Runoff Volume=0.023 af Runoff Depth=3.71" Flow Length=54' Slope=0.0022 '/' Tc=6.0 min CN=71 0.33 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 2HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: EX-3 Runoff = 1.72 cfs @ 12.09 hrs, Volume= 0.126 af, Depth= 5.35" Routed to Reach OP-3 : SOUTHERN CB (OLD TOWNHOUSE ROAD) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 1,385 39 >75% Grass cover, Good, HSG A 6,596 98 Paved parking, HSG A 3,036 76 Gravel roads, HSG A 1,323 98 Roofs, HSG A 12,340 86 Weighted Average 4,421 35.83% Pervious Area 7,919 64.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.3 100 0.0145 1.31 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 0.3 52 0.0204 2.90 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.6 152 Total, Increased to minimum Tc = 6.0 min Subcatchment 2S: EX-3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=12,340 sf Runoff Volume=0.126 af Runoff Depth=5.35" Flow Length=152' Tc=6.0 min CN=86 1.72 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 3HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: EX-4 Runoff = 0.57 cfs @ 12.08 hrs, Volume= 0.045 af, Depth= 6.50" Routed to Reach OP-4 : NORTHEAST LEACHING CB (STATION AVE) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 136 39 >75% Grass cover, Good, HSG A 3,095 98 Paved parking, HSG A 396 98 Roofs, HSG A 3,627 96 Weighted Average 136 3.75% Pervious Area 3,491 96.25% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 81 0.0204 1.44 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 0.9 81 Total, Increased to minimum Tc = 6.0 min Subcatchment 3S: EX-4 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=3,627 sf Runoff Volume=0.045 af Runoff Depth=6.50" Flow Length=81' Slope=0.0204 '/' Tc=6.0 min CN=96 0.57 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 4HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: EX-5 Runoff = 0.17 cfs @ 12.10 hrs, Volume= 0.013 af, Depth= 2.02" Routed to Reach OP-4 : NORTHEAST LEACHING CB (STATION AVE) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 2,164 39 >75% Grass cover, Good, HSG A 164 98 Paved parking, HSG A 1,084 76 Gravel roads, HSG A 3,412 54 Weighted Average 3,248 95.19% Pervious Area 164 4.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 99 0.0288 1.72 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 1.0 99 Total, Increased to minimum Tc = 6.0 min Subcatchment 4S: EX-5 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=3,412 sf Runoff Volume=0.013 af Runoff Depth=2.02" Flow Length=99' Slope=0.0288 '/' Tc=6.0 min CN=54 0.17 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 5HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: EX-6 Runoff = 0.93 cfs @ 12.09 hrs, Volume= 0.068 af, Depth= 5.23" Routed to Reach OP-5 : OLD TOWNHOUSE ROAD Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 203 39 >75% Grass cover, Good, HSG A 2,083 98 Roofs, HSG A 3,405 76 Gravel roads, HSG A 1,107 98 Roofs, HSG A 6,798 85 Weighted Average 3,608 53.07% Pervious Area 3,190 46.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.8 76 0.0276 1.60 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 0.8 76 Total, Increased to minimum Tc = 6.0 min Subcatchment 5S: EX-6 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=6,798 sf Runoff Volume=0.068 af Runoff Depth=5.23" Flow Length=76' Slope=0.0276 '/' Tc=6.0 min CN=85 0.93 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 6HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: EX-7 Runoff = 0.81 cfs @ 12.08 hrs, Volume= 0.065 af, Depth= 6.50" Routed to Reach OP-6 : STATION AVE Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 150 39 >75% Grass cover, Good, HSG A 4,451 98 Paved parking, HSG A 104 76 Gravel roads, HSG A 518 98 Roofs, HSG A 5,223 96 Weighted Average 254 4.86% Pervious Area 4,969 95.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 64 0.0135 1.16 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 0.9 64 Total, Increased to minimum Tc = 6.0 min Subcatchment 6S: EX-7 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=5,223 sf Runoff Volume=0.065 af Runoff Depth=6.50" Flow Length=64' Slope=0.0135 '/' Tc=6.0 min CN=96 0.81 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 7HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: EX-8 Runoff = 0.01 cfs @ 12.13 hrs, Volume= 0.001 af, Depth= 0.91" Routed to Reach OP-3 : SOUTHERN CB (OLD TOWNHOUSE ROAD) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 819 39 >75% Grass cover, Good, HSG A 30 98 Paved parking, HSG A 849 41 Weighted Average 819 96.47% Pervious Area 30 3.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 14 0.0162 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.74" 2.0 14 Total, Increased to minimum Tc = 6.0 min Subcatchment 7S: EX-8 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=849 sf Runoff Volume=0.001 af Runoff Depth=0.91" Flow Length=14' Slope=0.0162 '/' Tc=6.0 min CN=41 0.01 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 8HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment EX-1: EX-1 Runoff = 0.28 cfs @ 12.08 hrs, Volume= 0.022 af, Depth= 6.50" Routed to Reach OP-1 : NORTHERN LEACHING CATCH BASIN (OP-1) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 71 39 >75% Grass cover, Good, HSG A 1,586 98 Paved parking, HSG A 117 98 Roofs, HSG A 1,774 96 Weighted Average 71 4.00% Pervious Area 1,703 96.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.6 57 0.0360 1.68 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.74" 0.6 57 Total, Increased to minimum Tc = 6.0 min Subcatchment EX-1: EX-1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.3 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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=1,774 sf Runoff Volume=0.022 af Runoff Depth=6.50" Flow Length=57' Slope=0.0360 '/' Tc=6.0 min CN=96 0.28 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 9HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.041 ac, 96.00% Impervious, Inflow Depth = 6.50" for 50-yr event Inflow = 0.28 cfs @ 12.08 hrs, Volume= 0.022 af Outflow = 0.28 cfs @ 12.08 hrs, Volume= 0.022 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Reach OP-1: NORTHERN LEACHING CATCH BASIN (OP-1) Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.3 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 Inflow Area=0.041 ac 0.28 cfs 0.28 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 10HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-2: NORTHWEST LOT LINE (88-89) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.075 ac, 53.50% Impervious, Inflow Depth = 3.71" for 50-yr event Inflow = 0.33 cfs @ 12.09 hrs, Volume= 0.023 af Outflow = 0.33 cfs @ 12.09 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Reach OP-2: NORTHWEST LOT LINE (88-89) Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.36 0.34 0.32 0.3 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 Inflow Area=0.075 ac 0.33 cfs 0.33 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 11HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.303 ac, 60.27% Impervious, Inflow Depth = 5.06" for 50-yr event Inflow = 1.73 cfs @ 12.09 hrs, Volume= 0.128 af Outflow = 1.73 cfs @ 12.09 hrs, Volume= 0.128 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Reach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=0.303 ac 1.73 cfs 1.73 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 12HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-4: NORTHEAST LEACHING CB (STATION AVE) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.162 ac, 51.92% Impervious, Inflow Depth = 4.33" for 50-yr event Inflow = 0.73 cfs @ 12.09 hrs, Volume= 0.058 af Outflow = 0.73 cfs @ 12.09 hrs, Volume= 0.058 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Reach OP-4: NORTHEAST LEACHING CB (STATION AVE) Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.8 0.75 0.7 0.65 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 Inflow Area=0.162 ac 0.73 cfs 0.73 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 13HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-5: OLD TOWNHOUSE ROAD [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.156 ac, 46.93% Impervious, Inflow Depth = 5.23" for 50-yr event Inflow = 0.93 cfs @ 12.09 hrs, Volume= 0.068 af Outflow = 0.93 cfs @ 12.09 hrs, Volume= 0.068 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Reach OP-5: OLD TOWNHOUSE ROAD Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=0.156 ac 0.93 cfs 0.93 cfs Pre-Developed Conditions Type III 24-hr 50-yr Rainfall=6.98"25-0275EX00 Printed 10/8/2025Prepared by McClure Page 14HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-6: STATION AVE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.120 ac, 95.14% Impervious, Inflow Depth = 6.50" for 50-yr event Inflow = 0.81 cfs @ 12.08 hrs, Volume= 0.065 af Outflow = 0.81 cfs @ 12.08 hrs, Volume= 0.065 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Reach OP-6: STATION AVE Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 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 Inflow Area=0.120 ac 0.81 cfs 0.81 cfs 2S S1 3S S10 4S S2 5S S3 6S S4 7S S5 8S S6 9S S7 10S S8 S9 S9 OP-2 NORTHWEST LOT LINE (88-89) OP-3 SOUTHERN CB (OLD TOWNHOUSE ROAD) OP-5 OLD TOWNHOUSE ROAD OP-6 STATION AVE CB-1 CB CB-1 CB-2 CB CB-2 CB-3 CB CB-3 CB-4 CB CB-4 CB-5 CB CB-5 P1CB DMH-1 P2CB DMH-2 P3CB DMH-3 P4CB DMH-4 P5 CHAMBERS P6CB ADS DURASLOT TRENCH Routing Diagram for 25-0275DV00 Prepared by McClure, Printed 1/14/2026 HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Subcat Reach Pond Link DEVELOPED CONDITIONS 25-0275DV00 Printed 1/14/2026Prepared by McClure Page 2HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.312 39 >75% Grass cover, Good HSG A (2S, 4S, 5S, 6S, 7S, 8S, 9S, 10S, S9) 0.495 98 Paved parking HSG A (2S, 4S, 5S, 6S, 7S, 8S, 9S, 10S) 0.049 98 Roofs HSG A (3S) 0.856 76 TOTAL AREA DEVELOPED CONDITIONS 25-0275DV00 Printed 1/14/2026Prepared by McClure Page 3HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.856 HSG A 2S, 3S, 4S, 5S, 6S, 7S, 8S, 9S, 10S, S9 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 0.856 TOTAL AREA DEVELOPED CONDITIONS 25-0275DV00 Printed 1/14/2026Prepared by McClure Page 4HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.312 0.000 0.000 0.000 0.000 0.312 >75% Grass cover, Good 2S, 4S, 5S, 6S, 7S, 8S, 9S, 10S, S9 0.495 0.000 0.000 0.000 0.000 0.495 Paved parking 2S, 4S, 5S, 6S, 7S, 8S, 9S, 10S 0.049 0.000 0.000 0.000 0.000 0.049 Roofs 3S 0.856 0.000 0.000 0.000 0.000 0.856 TOTAL AREA DEVELOPED CONDITIONS Type III 24-hr 2-yr Rainfall=3.27"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 5HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points x 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=2,184 sf 0.04% Impervious Runoff Depth=0.00"Subcatchment 2S: S1 Flow Length=22' Slope=0.1311 '/' Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Runoff Area=2,136 sf 100.00% Impervious Runoff Depth=3.04"Subcatchment 3S: S10 Flow Length=15' Slope=0.0050 '/' Tc=6.0 min CN=98 Runoff=0.16 cfs 0.012 af Runoff Area=7,659 sf 4.23% Impervious Runoff Depth=0.01"Subcatchment 4S: S2 Flow Length=26' Slope=0.0626 '/' Tc=6.0 min CN=41 Runoff=0.00 cfs 0.000 af Runoff Area=8,120 sf 97.99% Impervious Runoff Depth=2.93"Subcatchment 5S: S3 Flow Length=134' Slope=0.0388 '/' Tc=6.0 min CN=97 Runoff=0.58 cfs 0.045 af Runoff Area=2,172 sf 83.81% Impervious Runoff Depth=2.06"Subcatchment 6S: S4 Flow Length=74' Slope=0.0598 '/' Tc=6.0 min CN=88 Runoff=0.12 cfs 0.009 af Runoff Area=3,337 sf 83.69% Impervious Runoff Depth=2.06"Subcatchment 7S: S5 Flow Length=98' Slope=0.1017 '/' Tc=6.0 min CN=88 Runoff=0.18 cfs 0.013 af Runoff Area=439 sf 83.64% Impervious Runoff Depth=2.06"Subcatchment 8S: S6 Flow Length=46' Slope=0.1314 '/' Tc=6.0 min CN=88 Runoff=0.02 cfs 0.002 af Runoff Area=1,464 sf 69.90% Impervious Runoff Depth=1.46"Subcatchment 9S: S7 Flow Length=77' Slope=0.0687 '/' Tc=6.0 min CN=80 Runoff=0.06 cfs 0.004 af Runoff Area=9,257 sf 78.71% Impervious Runoff Depth=1.82"Subcatchment 10S: S8 Flow Length=114' Slope=0.0777 '/' Tc=6.0 min CN=85 Runoff=0.45 cfs 0.032 af Runoff Area=541 sf 0.00% Impervious Runoff Depth=0.00"Subcatchment S9: S9 Flow Length=27' Slope=0.0884 '/' Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Inflow=0.00 cfs 0.000 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.00 cfs 0.000 af Inflow=0.00 cfs 0.000 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=0.00 cfs 0.000 af Inflow=0.00 cfs 0.000 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.00 cfs 0.000 af Inflow=0.00 cfs 0.000 afReach OP-6: STATION AVE Outflow=0.00 cfs 0.000 af Peak Elev=44.23' Inflow=0.12 cfs 0.009 afPond CB-1: CB-1 12.0" Round Culvert n=0.012 L=12.0' S=0.0083 '/' Outflow=0.12 cfs 0.009 af Peak Elev=43.71' Inflow=0.06 cfs 0.004 afPond CB-2: CB-2 12.0" Round Culvert n=0.012 L=23.0' S=0.0104 '/' Outflow=0.06 cfs 0.004 af DEVELOPED CONDITIONS Type III 24-hr 2-yr Rainfall=3.27"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 6HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Peak Elev=44.24' Inflow=0.18 cfs 0.013 afPond CB-3: CB-3 15.0" Round Culvert n=0.012 L=11.0' S=0.0273 '/' Outflow=0.18 cfs 0.013 af Peak Elev=45.08' Inflow=0.02 cfs 0.002 afPond CB-4: CB-4 15.0" Round Culvert n=0.012 L=10.4' S=0.0481 '/' Outflow=0.02 cfs 0.002 af Peak Elev=45.35' Inflow=0.45 cfs 0.032 afPond CB-5: CB-5 Primary=0.45 cfs 0.032 af Secondary=0.00 cfs 0.000 af Outflow=0.45 cfs 0.032 af Peak Elev=43.70' Inflow=1.58 cfs 0.118 afPond P1: DMH-1 15.0" Round Culvert n=0.012 L=32.6' S=0.0077 '/' Outflow=1.58 cfs 0.118 af Peak Elev=44.11' Inflow=0.82 cfs 0.059 afPond P2: DMH-2 15.0" Round Culvert n=0.012 L=67.0' S=0.0060 '/' Outflow=0.82 cfs 0.059 af Peak Elev=44.77' Inflow=0.48 cfs 0.034 afPond P3: DMH-3 15.0" Round Culvert n=0.012 L=121.0' S=0.0058 '/' Outflow=0.48 cfs 0.034 af Peak Elev=44.15' Inflow=0.70 cfs 0.054 afPond P4: DMH-4 15.0" Round Culvert n=0.012 L=65.0' S=0.0077 '/' Outflow=0.70 cfs 0.054 af Peak Elev=42.01' Storage=0.035 af Inflow=1.58 cfs 0.118 afPond P5: CHAMBERS Discarded=0.22 cfs 0.118 af Secondary=0.00 cfs 0.000 af Outflow=0.22 cfs 0.118 af Peak Elev=44.67' Inflow=0.58 cfs 0.045 afPond P6: ADS DURASLOT TRENCH 12.0" Round Culvert n=0.012 L=16.0' S=0.0206 '/' Outflow=0.58 cfs 0.045 af Total Runoff Area = 0.856 ac Runoff Volume = 0.118 af Average Runoff Depth = 1.65" 36.46% Pervious = 0.312 ac 63.54% Impervious = 0.544 ac DEVELOPED CONDITIONS Type III 24-hr 10-yr Rainfall=4.77"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 7HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points x 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=2,184 sf 0.04% Impervious Runoff Depth=0.16"Subcatchment 2S: S1 Flow Length=22' Slope=0.1311 '/' Tc=6.0 min CN=39 Runoff=0.00 cfs 0.001 af Runoff Area=2,136 sf 100.00% Impervious Runoff Depth=4.53"Subcatchment 3S: S10 Flow Length=15' Slope=0.0050 '/' Tc=6.0 min CN=98 Runoff=0.23 cfs 0.019 af Runoff Area=7,659 sf 4.23% Impervious Runoff Depth=0.22"Subcatchment 4S: S2 Flow Length=26' Slope=0.0626 '/' Tc=6.0 min CN=41 Runoff=0.01 cfs 0.003 af Runoff Area=8,120 sf 97.99% Impervious Runoff Depth=4.42"Subcatchment 5S: S3 Flow Length=134' Slope=0.0388 '/' Tc=6.0 min CN=97 Runoff=0.86 cfs 0.069 af Runoff Area=2,172 sf 83.81% Impervious Runoff Depth=3.45"Subcatchment 6S: S4 Flow Length=74' Slope=0.0598 '/' Tc=6.0 min CN=88 Runoff=0.20 cfs 0.014 af Runoff Area=3,337 sf 83.69% Impervious Runoff Depth=3.45"Subcatchment 7S: S5 Flow Length=98' Slope=0.1017 '/' Tc=6.0 min CN=88 Runoff=0.30 cfs 0.022 af Runoff Area=439 sf 83.64% Impervious Runoff Depth=3.45"Subcatchment 8S: S6 Flow Length=46' Slope=0.1314 '/' Tc=6.0 min CN=88 Runoff=0.04 cfs 0.003 af Runoff Area=1,464 sf 69.90% Impervious Runoff Depth=2.69"Subcatchment 9S: S7 Flow Length=77' Slope=0.0687 '/' Tc=6.0 min CN=80 Runoff=0.11 cfs 0.008 af Runoff Area=9,257 sf 78.71% Impervious Runoff Depth=3.16"Subcatchment 10S: S8 Flow Length=114' Slope=0.0777 '/' Tc=6.0 min CN=85 Runoff=0.78 cfs 0.056 af Runoff Area=541 sf 0.00% Impervious Runoff Depth=0.16"Subcatchment S9: S9 Flow Length=27' Slope=0.0884 '/' Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Inflow=0.00 cfs 0.001 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.00 cfs 0.001 af Inflow=0.00 cfs 0.000 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=0.00 cfs 0.000 af Inflow=0.00 cfs 0.000 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.00 cfs 0.000 af Inflow=0.01 cfs 0.003 afReach OP-6: STATION AVE Outflow=0.01 cfs 0.003 af Peak Elev=44.36' Inflow=0.20 cfs 0.014 afPond CB-1: CB-1 12.0" Round Culvert n=0.012 L=12.0' S=0.0083 '/' Outflow=0.20 cfs 0.014 af Peak Elev=43.94' Inflow=0.11 cfs 0.008 afPond CB-2: CB-2 12.0" Round Culvert n=0.012 L=23.0' S=0.0104 '/' Outflow=0.11 cfs 0.008 af DEVELOPED CONDITIONS Type III 24-hr 10-yr Rainfall=4.77"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 8HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Peak Elev=44.39' Inflow=0.30 cfs 0.022 afPond CB-3: CB-3 15.0" Round Culvert n=0.012 L=11.0' S=0.0273 '/' Outflow=0.30 cfs 0.022 af Peak Elev=45.10' Inflow=0.04 cfs 0.003 afPond CB-4: CB-4 15.0" Round Culvert n=0.012 L=10.4' S=0.0481 '/' Outflow=0.04 cfs 0.003 af Peak Elev=45.47' Inflow=0.78 cfs 0.056 afPond CB-5: CB-5 Primary=0.78 cfs 0.056 af Secondary=0.00 cfs 0.000 af Outflow=0.78 cfs 0.056 af Peak Elev=43.94' Inflow=2.52 cfs 0.190 afPond P1: DMH-1 15.0" Round Culvert n=0.012 L=32.6' S=0.0077 '/' Outflow=2.52 cfs 0.190 af Peak Elev=44.32' Inflow=1.35 cfs 0.099 afPond P2: DMH-2 15.0" Round Culvert n=0.012 L=67.0' S=0.0060 '/' Outflow=1.35 cfs 0.099 af Peak Elev=44.91' Inflow=0.82 cfs 0.059 afPond P3: DMH-3 15.0" Round Culvert n=0.012 L=121.0' S=0.0058 '/' Outflow=0.82 cfs 0.059 af Peak Elev=44.31' Inflow=1.06 cfs 0.083 afPond P4: DMH-4 15.0" Round Culvert n=0.012 L=65.0' S=0.0077 '/' Outflow=1.06 cfs 0.083 af Peak Elev=43.73' Storage=0.069 af Inflow=2.52 cfs 0.190 afPond P5: CHAMBERS Discarded=0.22 cfs 0.190 af Secondary=0.00 cfs 0.000 af Outflow=0.22 cfs 0.190 af Peak Elev=44.77' Inflow=0.86 cfs 0.069 afPond P6: ADS DURASLOT TRENCH 12.0" Round Culvert n=0.012 L=16.0' S=0.0206 '/' Outflow=0.86 cfs 0.069 af Total Runoff Area = 0.856 ac Runoff Volume = 0.194 af Average Runoff Depth = 2.72" 36.46% Pervious = 0.312 ac 63.54% Impervious = 0.544 ac DEVELOPED CONDITIONS Type III 24-hr 25-yr Rainfall=5.92"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 9HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points x 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=2,184 sf 0.04% Impervious Runoff Depth=0.42"Subcatchment 2S: S1 Flow Length=22' Slope=0.1311 '/' Tc=6.0 min CN=39 Runoff=0.01 cfs 0.002 af Runoff Area=2,136 sf 100.00% Impervious Runoff Depth=5.68"Subcatchment 3S: S10 Flow Length=15' Slope=0.0050 '/' Tc=6.0 min CN=98 Runoff=0.28 cfs 0.023 af Runoff Area=7,659 sf 4.23% Impervious Runoff Depth=0.53"Subcatchment 4S: S2 Flow Length=26' Slope=0.0626 '/' Tc=6.0 min CN=41 Runoff=0.04 cfs 0.008 af Runoff Area=8,120 sf 97.99% Impervious Runoff Depth=5.56"Subcatchment 5S: S3 Flow Length=134' Slope=0.0388 '/' Tc=6.0 min CN=97 Runoff=1.08 cfs 0.086 af Runoff Area=2,172 sf 83.81% Impervious Runoff Depth=4.55"Subcatchment 6S: S4 Flow Length=74' Slope=0.0598 '/' Tc=6.0 min CN=88 Runoff=0.26 cfs 0.019 af Runoff Area=3,337 sf 83.69% Impervious Runoff Depth=4.55"Subcatchment 7S: S5 Flow Length=98' Slope=0.1017 '/' Tc=6.0 min CN=88 Runoff=0.40 cfs 0.029 af Runoff Area=439 sf 83.64% Impervious Runoff Depth=4.55"Subcatchment 8S: S6 Flow Length=46' Slope=0.1314 '/' Tc=6.0 min CN=88 Runoff=0.05 cfs 0.004 af Runoff Area=1,464 sf 69.90% Impervious Runoff Depth=3.71"Subcatchment 9S: S7 Flow Length=77' Slope=0.0687 '/' Tc=6.0 min CN=80 Runoff=0.15 cfs 0.010 af Runoff Area=9,257 sf 78.71% Impervious Runoff Depth=4.23"Subcatchment 10S: S8 Flow Length=114' Slope=0.0777 '/' Tc=6.0 min CN=85 Runoff=1.03 cfs 0.075 af Runoff Area=541 sf 0.00% Impervious Runoff Depth=0.42"Subcatchment S9: S9 Flow Length=27' Slope=0.0884 '/' Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Inflow=0.01 cfs 0.002 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.01 cfs 0.002 af Inflow=0.00 cfs 0.000 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=0.00 cfs 0.000 af Inflow=0.00 cfs 0.000 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.00 cfs 0.000 af Inflow=0.04 cfs 0.008 afReach OP-6: STATION AVE Outflow=0.04 cfs 0.008 af Peak Elev=45.68' Inflow=0.26 cfs 0.019 afPond CB-1: CB-1 12.0" Round Culvert n=0.012 L=12.0' S=0.0083 '/' Outflow=0.26 cfs 0.019 af Peak Elev=45.68' Inflow=0.15 cfs 0.010 afPond CB-2: CB-2 12.0" Round Culvert n=0.012 L=23.0' S=0.0104 '/' Outflow=0.15 cfs 0.010 af DEVELOPED CONDITIONS Type III 24-hr 25-yr Rainfall=5.92"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 10HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Peak Elev=45.68' Inflow=0.40 cfs 0.029 afPond CB-3: CB-3 15.0" Round Culvert n=0.012 L=11.0' S=0.0273 '/' Outflow=0.40 cfs 0.029 af Peak Elev=45.67' Inflow=0.05 cfs 0.004 afPond CB-4: CB-4 15.0" Round Culvert n=0.012 L=10.4' S=0.0481 '/' Outflow=0.05 cfs 0.004 af Peak Elev=45.69' Inflow=1.03 cfs 0.075 afPond CB-5: CB-5 Primary=1.03 cfs 0.075 af Secondary=0.00 cfs 0.000 af Outflow=1.03 cfs 0.075 af Peak Elev=45.68' Inflow=3.24 cfs 0.247 afPond P1: DMH-1 15.0" Round Culvert n=0.012 L=32.6' S=0.0077 '/' Outflow=3.24 cfs 0.247 af Peak Elev=45.68' Inflow=1.77 cfs 0.131 afPond P2: DMH-2 15.0" Round Culvert n=0.012 L=67.0' S=0.0060 '/' Outflow=1.77 cfs 0.131 af Peak Elev=45.69' Inflow=1.09 cfs 0.079 afPond P3: DMH-3 15.0" Round Culvert n=0.012 L=121.0' S=0.0058 '/' Outflow=1.09 cfs 0.079 af Peak Elev=45.68' Inflow=1.33 cfs 0.105 afPond P4: DMH-4 15.0" Round Culvert n=0.012 L=65.0' S=0.0077 '/' Outflow=1.33 cfs 0.105 af Peak Elev=45.68' Storage=0.100 af Inflow=3.24 cfs 0.247 afPond P5: CHAMBERS Discarded=0.22 cfs 0.247 af Secondary=0.00 cfs 0.000 af Outflow=0.22 cfs 0.247 af Peak Elev=45.68' Inflow=1.08 cfs 0.086 afPond P6: ADS DURASLOT TRENCH 12.0" Round Culvert n=0.012 L=16.0' S=0.0206 '/' Outflow=1.08 cfs 0.086 af Total Runoff Area = 0.856 ac Runoff Volume = 0.257 af Average Runoff Depth = 3.60" 36.46% Pervious = 0.312 ac 63.54% Impervious = 0.544 ac DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 11HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points x 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=2,184 sf 0.04% Impervious Runoff Depth=0.76"Subcatchment 2S: S1 Flow Length=22' Slope=0.1311 '/' Tc=6.0 min CN=39 Runoff=0.02 cfs 0.003 af Runoff Area=2,136 sf 100.00% Impervious Runoff Depth=6.74"Subcatchment 3S: S10 Flow Length=15' Slope=0.0050 '/' Tc=6.0 min CN=98 Runoff=0.34 cfs 0.028 af Runoff Area=7,659 sf 4.23% Impervious Runoff Depth=0.91"Subcatchment 4S: S2 Flow Length=26' Slope=0.0626 '/' Tc=6.0 min CN=41 Runoff=0.11 cfs 0.013 af Runoff Area=8,120 sf 97.99% Impervious Runoff Depth=6.62"Subcatchment 5S: S3 Flow Length=134' Slope=0.0388 '/' Tc=6.0 min CN=97 Runoff=1.27 cfs 0.103 af Runoff Area=2,172 sf 83.81% Impervious Runoff Depth=5.57"Subcatchment 6S: S4 Flow Length=74' Slope=0.0598 '/' Tc=6.0 min CN=88 Runoff=0.31 cfs 0.023 af Runoff Area=3,337 sf 83.69% Impervious Runoff Depth=5.57"Subcatchment 7S: S5 Flow Length=98' Slope=0.1017 '/' Tc=6.0 min CN=88 Runoff=0.48 cfs 0.036 af Runoff Area=439 sf 83.64% Impervious Runoff Depth=5.57"Subcatchment 8S: S6 Flow Length=46' Slope=0.1314 '/' Tc=6.0 min CN=88 Runoff=0.06 cfs 0.005 af Runoff Area=1,464 sf 69.90% Impervious Runoff Depth=4.68"Subcatchment 9S: S7 Flow Length=77' Slope=0.0687 '/' Tc=6.0 min CN=80 Runoff=0.18 cfs 0.013 af Runoff Area=9,257 sf 78.71% Impervious Runoff Depth=5.23"Subcatchment 10S: S8 Flow Length=114' Slope=0.0777 '/' Tc=6.0 min CN=85 Runoff=1.27 cfs 0.093 af Runoff Area=541 sf 0.00% Impervious Runoff Depth=0.76"Subcatchment S9: S9 Flow Length=27' Slope=0.0884 '/' Tc=6.0 min CN=39 Runoff=0.01 cfs 0.001 af Inflow=0.02 cfs 0.003 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.02 cfs 0.003 af Inflow=0.00 cfs 0.000 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=0.00 cfs 0.000 af Inflow=0.01 cfs 0.001 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.01 cfs 0.001 af Inflow=0.11 cfs 0.013 afReach OP-6: STATION AVE Outflow=0.11 cfs 0.013 af Peak Elev=46.83' Inflow=0.31 cfs 0.023 afPond CB-1: CB-1 12.0" Round Culvert n=0.012 L=12.0' S=0.0083 '/' Outflow=0.31 cfs 0.023 af Peak Elev=46.81' Inflow=0.18 cfs 0.013 afPond CB-2: CB-2 12.0" Round Culvert n=0.012 L=23.0' S=0.0104 '/' Outflow=0.18 cfs 0.013 af DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 12HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Peak Elev=46.83' Inflow=0.48 cfs 0.036 afPond CB-3: CB-3 15.0" Round Culvert n=0.012 L=11.0' S=0.0273 '/' Outflow=0.48 cfs 0.036 af Peak Elev=47.03' Inflow=0.06 cfs 0.005 afPond CB-4: CB-4 15.0" Round Culvert n=0.012 L=10.4' S=0.0481 '/' Outflow=0.06 cfs 0.005 af Peak Elev=46.85' Inflow=1.27 cfs 0.093 afPond CB-5: CB-5 Primary=1.27 cfs 0.093 af Secondary=0.00 cfs 0.000 af Outflow=1.27 cfs 0.093 af Peak Elev=46.81' Inflow=3.91 cfs 0.300 afPond P1: DMH-1 15.0" Round Culvert n=0.012 L=32.6' S=0.0077 '/' Outflow=3.91 cfs 0.300 af Peak Elev=46.83' Inflow=2.15 cfs 0.160 afPond P2: DMH-2 15.0" Round Culvert n=0.012 L=67.0' S=0.0060 '/' Outflow=2.15 cfs 0.160 af Peak Elev=46.84' Inflow=1.33 cfs 0.097 afPond P3: DMH-3 15.0" Round Culvert n=0.012 L=121.0' S=0.0058 '/' Outflow=1.33 cfs 0.097 af Peak Elev=46.83' Inflow=1.58 cfs 0.126 afPond P4: DMH-4 15.0" Round Culvert n=0.012 L=65.0' S=0.0077 '/' Outflow=1.58 cfs 0.126 af Peak Elev=46.75' Storage=0.111 af Inflow=3.91 cfs 0.300 afPond P5: CHAMBERS Discarded=0.22 cfs 0.280 af Secondary=1.02 cfs 0.020 af Outflow=1.24 cfs 0.300 af Peak Elev=46.84' Inflow=1.27 cfs 0.103 afPond P6: ADS DURASLOT TRENCH 12.0" Round Culvert n=0.012 L=16.0' S=0.0206 '/' Outflow=1.27 cfs 0.103 af Total Runoff Area = 0.856 ac Runoff Volume = 0.317 af Average Runoff Depth = 4.44" 36.46% Pervious = 0.312 ac 63.54% Impervious = 0.544 ac DEVELOPED CONDITIONS Type III 24-hr 100-yr Rainfall=8.23"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 13HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points x 3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=2,184 sf 0.04% Impervious Runoff Depth=1.25"Subcatchment 2S: S1 Flow Length=22' Slope=0.1311 '/' Tc=6.0 min CN=39 Runoff=0.05 cfs 0.005 af Runoff Area=2,136 sf 100.00% Impervious Runoff Depth=7.99"Subcatchment 3S: S10 Flow Length=15' Slope=0.0050 '/' Tc=6.0 min CN=98 Runoff=0.40 cfs 0.033 af Runoff Area=7,659 sf 4.23% Impervious Runoff Depth=1.45"Subcatchment 4S: S2 Flow Length=26' Slope=0.0626 '/' Tc=6.0 min CN=41 Runoff=0.23 cfs 0.021 af Runoff Area=8,120 sf 97.99% Impervious Runoff Depth=7.87"Subcatchment 5S: S3 Flow Length=134' Slope=0.0388 '/' Tc=6.0 min CN=97 Runoff=1.50 cfs 0.122 af Runoff Area=2,172 sf 83.81% Impervious Runoff Depth=6.79"Subcatchment 6S: S4 Flow Length=74' Slope=0.0598 '/' Tc=6.0 min CN=88 Runoff=0.38 cfs 0.028 af Runoff Area=3,337 sf 83.69% Impervious Runoff Depth=6.79"Subcatchment 7S: S5 Flow Length=98' Slope=0.1017 '/' Tc=6.0 min CN=88 Runoff=0.58 cfs 0.043 af Runoff Area=439 sf 83.64% Impervious Runoff Depth=6.79"Subcatchment 8S: S6 Flow Length=46' Slope=0.1314 '/' Tc=6.0 min CN=88 Runoff=0.08 cfs 0.006 af Runoff Area=1,464 sf 69.90% Impervious Runoff Depth=5.84"Subcatchment 9S: S7 Flow Length=77' Slope=0.0687 '/' Tc=6.0 min CN=80 Runoff=0.23 cfs 0.016 af Runoff Area=9,257 sf 78.71% Impervious Runoff Depth=6.44"Subcatchment 10S: S8 Flow Length=114' Slope=0.0777 '/' Tc=6.0 min CN=85 Runoff=1.54 cfs 0.114 af Runoff Area=541 sf 0.00% Impervious Runoff Depth=1.25"Subcatchment S9: S9 Flow Length=27' Slope=0.0884 '/' Tc=6.0 min CN=39 Runoff=0.01 cfs 0.001 af Inflow=0.05 cfs 0.005 afReach OP-2: NORTHWEST LOT LINE (88-89) Outflow=0.05 cfs 0.005 af Inflow=0.00 cfs 0.000 afReach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Outflow=0.00 cfs 0.000 af Inflow=0.01 cfs 0.001 afReach OP-5: OLD TOWNHOUSE ROAD Outflow=0.01 cfs 0.001 af Inflow=0.23 cfs 0.021 afReach OP-6: STATION AVE Outflow=0.23 cfs 0.021 af Peak Elev=47.09' Inflow=0.38 cfs 0.028 afPond CB-1: CB-1 12.0" Round Culvert n=0.012 L=12.0' S=0.0083 '/' Outflow=0.38 cfs 0.028 af Peak Elev=47.07' Inflow=0.23 cfs 0.016 afPond CB-2: CB-2 12.0" Round Culvert n=0.012 L=23.0' S=0.0104 '/' Outflow=0.23 cfs 0.016 af DEVELOPED CONDITIONS Type III 24-hr 100-yr Rainfall=8.23"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 14HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Peak Elev=47.13' Inflow=0.58 cfs 0.043 afPond CB-3: CB-3 15.0" Round Culvert n=0.012 L=11.0' S=0.0273 '/' Outflow=0.58 cfs 0.043 af Peak Elev=47.19' Inflow=0.08 cfs 0.006 afPond CB-4: CB-4 15.0" Round Culvert n=0.012 L=10.4' S=0.0481 '/' Outflow=0.08 cfs 0.006 af Peak Elev=47.23' Inflow=1.54 cfs 0.114 afPond CB-5: CB-5 Primary=1.54 cfs 0.114 af Secondary=0.00 cfs 0.000 af Outflow=1.54 cfs 0.114 af Peak Elev=47.07' Inflow=4.70 cfs 0.362 afPond P1: DMH-1 15.0" Round Culvert n=0.012 L=32.6' S=0.0077 '/' Outflow=4.70 cfs 0.362 af Peak Elev=47.17' Inflow=2.59 cfs 0.196 afPond P2: DMH-2 15.0" Round Culvert n=0.012 L=67.0' S=0.0060 '/' Outflow=2.59 cfs 0.196 af Peak Elev=47.17' Inflow=1.62 cfs 0.120 afPond P3: DMH-3 15.0" Round Culvert n=0.012 L=121.0' S=0.0058 '/' Outflow=1.62 cfs 0.120 af Peak Elev=47.12' Inflow=1.88 cfs 0.150 afPond P4: DMH-4 15.0" Round Culvert n=0.012 L=65.0' S=0.0077 '/' Outflow=1.88 cfs 0.150 af Peak Elev=46.75' Storage=0.111 af Inflow=4.70 cfs 0.362 afPond P5: CHAMBERS Discarded=0.22 cfs 0.303 af Secondary=2.45 cfs 0.060 af Outflow=2.67 cfs 0.362 af Peak Elev=47.16' Inflow=1.50 cfs 0.122 afPond P6: ADS DURASLOT TRENCH 12.0" Round Culvert n=0.012 L=16.0' S=0.0206 '/' Outflow=1.50 cfs 0.122 af Total Runoff Area = 0.856 ac Runoff Volume = 0.390 af Average Runoff Depth = 5.47" 36.46% Pervious = 0.312 ac 63.54% Impervious = 0.544 ac DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 1HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: S1 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.02 cfs @ 12.14 hrs, Volume= 0.003 af, Depth= 0.76" Routed to Reach OP-2 : NORTHWEST LOT LINE (88-89) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 1 98 Paved parking HSG A 2,184 39 >75% Grass cover, Good HSG A 2,184 39 Weighted Average 2,184 99.96% Pervious Area 1 0.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 22 0.1311 0.30 Lag/CN Method, 1.2 22 Total, Increased to minimum Tc = 6.0 min Subcatchment 2S: S1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.023 0.022 0.021 0.02 0.019 0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=2,184 sf Runoff Volume=0.003 af Runoff Depth=0.76" Flow Length=22' Slope=0.1311 '/' Tc=6.0 min CN=39 0.02 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 2HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: S10 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.34 cfs @ 12.08 hrs, Volume= 0.028 af, Depth= 6.74" Routed to Pond P2 : DMH-2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 2,136 98 Roofs HSG A 2,136 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.7 15 0.0050 0.34 Lag/CN Method, 0.7 15 Total, Increased to minimum Tc = 6.0 min Subcatchment 3S: S10 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.36 0.34 0.32 0.3 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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=2,136 sf Runoff Volume=0.028 af Runoff Depth=6.74" Flow Length=15' Slope=0.0050 '/' Tc=6.0 min CN=98 0.34 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 3HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: S2 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.11 cfs @ 12.13 hrs, Volume= 0.013 af, Depth= 0.91" Routed to Reach OP-6 : STATION AVE Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 324 98 Paved parking HSG A 7,335 39 >75% Grass cover, Good HSG A 7,659 41 Weighted Average 7,335 95.77% Pervious Area 324 4.23% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 26 0.0626 0.22 Lag/CN Method, 2.0 26 Total, Increased to minimum Tc = 6.0 min Subcatchment 4S: S2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.12 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=7,659 sf Runoff Volume=0.013 af Runoff Depth=0.91" Flow Length=26' Slope=0.0626 '/' Tc=6.0 min CN=41 0.11 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 4HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: S3 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 1.27 cfs @ 12.08 hrs, Volume= 0.103 af, Depth= 6.62" Routed to Pond P6 : ADS DURASLOT TRENCH Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 7,956 98 Paved parking HSG A 164 39 >75% Grass cover, Good HSG A 8,120 97 Weighted Average 164 2.01% Pervious Area 7,956 97.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.6 134 0.0388 1.38 Lag/CN Method, 1.6 134 Total, Increased to minimum Tc = 6.0 min Subcatchment 5S: S3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=8,120 sf Runoff Volume=0.103 af Runoff Depth=6.62" Flow Length=134' Slope=0.0388 '/' Tc=6.0 min CN=97 1.27 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 5HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: S4 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.31 cfs @ 12.08 hrs, Volume= 0.023 af, Depth= 5.57" Routed to Pond CB-1 : CB-1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 1,820 98 Paved parking HSG A 352 39 >75% Grass cover, Good HSG A 2,172 88 Weighted Average 352 16.19% Pervious Area 1,820 83.81% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 74 0.0598 1.00 Lag/CN Method, 1.2 74 Total, Increased to minimum Tc = 6.0 min Subcatchment 6S: S4 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.34 0.32 0.3 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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=2,172 sf Runoff Volume=0.023 af Runoff Depth=5.57" Flow Length=74' Slope=0.0598 '/' Tc=6.0 min CN=88 0.31 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 6HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: S5 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.48 cfs @ 12.08 hrs, Volume= 0.036 af, Depth= 5.57" Routed to Pond CB-3 : CB-3 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 2,793 98 Paved parking HSG A 544 39 >75% Grass cover, Good HSG A 3,337 88 Weighted Average 544 16.31% Pervious Area 2,793 83.69% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 98 0.1017 1.38 Lag/CN Method, 1.2 98 Total, Increased to minimum Tc = 6.0 min Subcatchment 7S: S5 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=3,337 sf Runoff Volume=0.036 af Runoff Depth=5.57" Flow Length=98' Slope=0.1017 '/' Tc=6.0 min CN=88 0.48 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 7HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: S6 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.06 cfs @ 12.08 hrs, Volume= 0.005 af, Depth= 5.57" Routed to Pond CB-4 : CB-4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 367 98 Paved parking HSG A 72 39 >75% Grass cover, Good HSG A 439 88 Weighted Average 72 16.36% Pervious Area 367 83.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.6 46 0.1314 1.35 Lag/CN Method, 0.6 46 Total, Increased to minimum Tc = 6.0 min Subcatchment 8S: S6 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=439 sf Runoff Volume=0.005 af Runoff Depth=5.57" Flow Length=46' Slope=0.1314 '/' Tc=6.0 min CN=88 0.06 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 8HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: S7 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.18 cfs @ 12.09 hrs, Volume= 0.013 af, Depth= 4.68" Routed to Pond CB-2 : CB-2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 1,023 98 Paved parking HSG A 441 39 >75% Grass cover, Good HSG A 1,464 80 Weighted Average 441 30.10% Pervious Area 1,023 69.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.6 77 0.0687 0.82 Lag/CN Method, 1.6 77 Total, Increased to minimum Tc = 6.0 min Subcatchment 9S: S7 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)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 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=1,464 sf Runoff Volume=0.013 af Runoff Depth=4.68" Flow Length=77' Slope=0.0687 '/' Tc=6.0 min CN=80 0.18 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 9HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: S8 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 1.27 cfs @ 12.09 hrs, Volume= 0.093 af, Depth= 5.23" Routed to Pond CB-5 : CB-5 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 7,286 98 Paved parking HSG A 1,971 39 >75% Grass cover, Good HSG A 9,257 85 Weighted Average 1,971 21.29% Pervious Area 7,286 78.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 114 0.0777 1.12 Lag/CN Method, 1.7 114 Total, Increased to minimum Tc = 6.0 min Subcatchment 10S: S8 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=9,257 sf Runoff Volume=0.093 af Runoff Depth=5.23" Flow Length=114' Slope=0.0777 '/' Tc=6.0 min CN=85 1.27 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 10HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment S9: S9 CarlsonPlanXYPos|0.0000|0.0000| Runoff = 0.01 cfs @ 12.14 hrs, Volume= 0.001 af, Depth= 0.76" Routed to Reach OP-5 : OLD TOWNHOUSE ROAD Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 50-yr Rainfall=6.98" Area (sf) CN Description 541 39 >75% Grass cover, Good HSG A 541 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 27 0.0884 0.25 Lag/CN Method, 1.7 27 Total, Increased to minimum Tc = 6.0 min Subcatchment S9: S9 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Type III 24-hr 50-yr Rainfall=6.98" Runoff Area=541 sf Runoff Volume=0.001 af Runoff Depth=0.76" Flow Length=27' Slope=0.0884 '/' Tc=6.0 min CN=39 0.01 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 11HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-2: NORTHWEST LOT LINE (88-89) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.050 ac, 0.04% Impervious, Inflow Depth = 0.76" for 50-yr event Inflow = 0.02 cfs @ 12.14 hrs, Volume= 0.003 af Outflow = 0.02 cfs @ 12.14 hrs, Volume= 0.003 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Reach OP-2: NORTHWEST LOT LINE (88-89) Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.023 0.022 0.021 0.02 0.019 0.018 0.017 0.016 0.015 0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Inflow Area=0.050 ac 0.02 cfs 0.02 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 12HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) [40] Hint: Not Described (Outflow=Inflow) Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Reach OP-3: SOUTHERN CB (OLD TOWNHOUSE ROAD) Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 0.00 cfs 0.00 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 13HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-5: OLD TOWNHOUSE ROAD [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.012 ac, 0.00% Impervious, Inflow Depth = 0.76" for 50-yr event Inflow = 0.01 cfs @ 12.14 hrs, Volume= 0.001 af Outflow = 0.01 cfs @ 12.14 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Reach OP-5: OLD TOWNHOUSE ROAD Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Inflow Area=0.012 ac 0.01 cfs 0.01 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 14HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Reach OP-6: STATION AVE [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.176 ac, 4.23% Impervious, Inflow Depth = 0.91" for 50-yr event Inflow = 0.11 cfs @ 12.13 hrs, Volume= 0.013 af Outflow = 0.11 cfs @ 12.13 hrs, Volume= 0.013 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Reach OP-6: STATION AVE Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.12 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.176 ac 0.11 cfs 0.11 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 15HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond CB-1: CB-1 [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=499) Inflow Area = 0.050 ac, 83.81% Impervious, Inflow Depth = 5.57" for 50-yr event Inflow = 0.31 cfs @ 12.08 hrs, Volume= 0.023 af Outflow = 0.31 cfs @ 12.08 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 min Primary = 0.31 cfs @ 12.08 hrs, Volume= 0.023 af Routed to Pond P4 : DMH-4 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.83' @ 12.42 hrs Flood Elev= 50.40' Device Routing Invert Outlet Devices #1 Primary 44.00'12.0" Round Culvert L= 12.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 44.00' / 43.90' S= 0.0083 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.31 cfs @ 12.08 hrs HW=44.62' TW=44.59' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.31 cfs @ 0.87 fps) Pond CB-1: CB-1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.34 0.32 0.3 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 Inflow Area=0.050 ac Peak Elev=46.83' 12.0" Round Culvert n=0.012 L=12.0' S=0.0083 '/' 0.31 cfs 0.31 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 16HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond CB-2: CB-2 [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=250) Inflow Area = 0.034 ac, 69.90% Impervious, Inflow Depth = 4.68" for 50-yr event Inflow = 0.18 cfs @ 12.09 hrs, Volume= 0.013 af Outflow = 0.18 cfs @ 12.09 hrs, Volume= 0.013 af, Atten= 0%, Lag= 0.0 min Primary = 0.18 cfs @ 12.09 hrs, Volume= 0.013 af Routed to Pond P1 : DMH-1 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.81' @ 12.42 hrs Flood Elev= 50.70' Device Routing Invert Outlet Devices #1 Primary 43.44'12.0" Round Culvert L= 23.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 43.44' / 43.20' S= 0.0104 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.18 cfs @ 12.09 hrs HW=44.33' TW=44.33' (Dynamic Tailwater) 1=Culvert (Inlet Controls 0.18 cfs @ 0.25 fps) Pond CB-2: CB-2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)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 Inflow Area=0.034 ac Peak Elev=46.81' 12.0" Round Culvert n=0.012 L=23.0' S=0.0104 '/' 0.18 cfs 0.18 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 17HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond CB-3: CB-3 [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=468) Inflow Area = 0.077 ac, 83.69% Impervious, Inflow Depth = 5.57" for 50-yr event Inflow = 0.48 cfs @ 12.08 hrs, Volume= 0.036 af Outflow = 0.48 cfs @ 12.08 hrs, Volume= 0.036 af, Atten= 0%, Lag= 0.0 min Primary = 0.48 cfs @ 12.08 hrs, Volume= 0.036 af Routed to Pond P2 : DMH-2 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.83' @ 12.42 hrs Flood Elev= 50.52' Device Routing Invert Outlet Devices #1 Primary 44.00'15.0" Round Culvert L= 11.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 44.00' / 43.70' S= 0.0273 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=0.48 cfs @ 12.08 hrs HW=44.68' TW=44.65' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.48 cfs @ 1.01 fps) Pond CB-3: CB-3 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.077 ac Peak Elev=46.83' 15.0" Round Culvert n=0.012 L=11.0' S=0.0273 '/' 0.48 cfs 0.48 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 18HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond CB-4: CB-4 [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=585) Inflow Area = 0.010 ac, 83.64% Impervious, Inflow Depth = 5.57" for 50-yr event Inflow = 0.06 cfs @ 12.08 hrs, Volume= 0.005 af Outflow = 0.06 cfs @ 12.08 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.0 min Primary = 0.06 cfs @ 12.08 hrs, Volume= 0.005 af Routed to Pond P3 : DMH-3 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 47.03' @ 12.42 hrs Flood Elev= 49.66' Device Routing Invert Outlet Devices #1 Primary 45.00'15.0" Round Culvert L= 10.4' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 45.00' / 44.50' S= 0.0481 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=0.06 cfs @ 12.08 hrs HW=45.17' TW=45.13' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.06 cfs @ 0.94 fps) Pond CB-4: CB-4 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.010 ac Peak Elev=47.03' 15.0" Round Culvert n=0.012 L=10.4' S=0.0481 '/' 0.06 cfs 0.06 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 19HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond CB-5: CB-5 Inflow Area = 0.213 ac, 78.71% Impervious, Inflow Depth = 5.23" for 50-yr event Inflow = 1.27 cfs @ 12.09 hrs, Volume= 0.093 af Outflow = 1.27 cfs @ 12.09 hrs, Volume= 0.093 af, Atten= 0%, Lag= 0.0 min Primary = 1.27 cfs @ 12.09 hrs, Volume= 0.093 af Routed to Pond P3 : DMH-3 Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Reach OP-3 : SOUTHERN CB (OLD TOWNHOUSE ROAD) Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.85' @ 12.42 hrs Flood Elev= 48.68' Device Routing Invert Outlet Devices #1 Primary 45.00'15.0" Round Culvert L= 48.7' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 45.00' / 44.50' S= 0.0103 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf #2 Secondary 48.68'2.0" W x 2.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=1.27 cfs @ 12.09 hrs HW=45.61' TW=45.13' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.27 cfs @ 2.11 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=45.00' TW=0.00' (Dynamic Tailwater) 2=Orifice/Grate ( Controls 0.00 cfs) DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 20HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Pond CB-5: CB-5 Inflow Outflow Primary Secondary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=0.213 ac Peak Elev=46.85' 1.27 cfs 1.27 cfs 1.27 cfs 0.00 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 21HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond P1: DMH-1 [80] Warning: Exceeded Pond CB-2 by 3.31' @ 13.03 hrs (5.01 cfs 0.376 af) Inflow Area = 0.618 ac, 86.84% Impervious, Inflow Depth = 5.82" for 50-yr event Inflow = 3.91 cfs @ 12.08 hrs, Volume= 0.300 af Outflow = 3.91 cfs @ 12.08 hrs, Volume= 0.300 af, Atten= 0%, Lag= 0.0 min Primary = 3.91 cfs @ 12.08 hrs, Volume= 0.300 af Routed to Pond P5 : CHAMBERS Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.81' @ 12.42 hrs Flood Elev= 51.01' Device Routing Invert Outlet Devices #1 Primary 43.00'15.0" Round Culvert L= 32.6' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 43.00' / 42.75' S= 0.0077 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=3.90 cfs @ 12.08 hrs HW=44.33' TW=43.21' (Dynamic Tailwater) 1=Culvert (Inlet Controls 3.90 cfs @ 3.18 fps) Pond P1: DMH-1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)4 3 2 1 0 Inflow Area=0.618 ac Peak Elev=46.81' 15.0" Round Culvert n=0.012 L=32.6' S=0.0077 '/' 3.91 cfs 3.91 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 22HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond P2: DMH-2 [80] Warning: Exceeded Pond CB-3 by 2.46' @ 15.03 hrs (6.33 cfs 0.293 af) [80] Warning: Exceeded Pond P3 by 0.09' @ 12.30 hrs (1.42 cfs 0.018 af) Inflow Area = 0.348 ac, 82.95% Impervious, Inflow Depth = 5.53" for 50-yr event Inflow = 2.15 cfs @ 12.08 hrs, Volume= 0.160 af Outflow = 2.15 cfs @ 12.08 hrs, Volume= 0.160 af, Atten= 0%, Lag= 0.0 min Primary = 2.15 cfs @ 12.08 hrs, Volume= 0.160 af Routed to Pond P1 : DMH-1 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.83' @ 12.42 hrs Flood Elev= 50.74' Device Routing Invert Outlet Devices #1 Primary 43.60'15.0" Round Culvert L= 67.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 43.60' / 43.20' S= 0.0060 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=2.14 cfs @ 12.08 hrs HW=44.65' TW=44.33' (Dynamic Tailwater) 1=Culvert (Outlet Controls 2.14 cfs @ 2.63 fps) Pond P2: DMH-2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Inflow Area=0.348 ac Peak Elev=46.83' 15.0" Round Culvert n=0.012 L=67.0' S=0.0060 '/' 2.15 cfs 2.15 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 23HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond P3: DMH-3 [80] Warning: Exceeded Pond CB-4 by 1.82' @ 12.43 hrs (5.11 cfs 0.257 af) Inflow Area = 0.223 ac, 78.93% Impervious, Inflow Depth = 5.25" for 50-yr event Inflow = 1.33 cfs @ 12.09 hrs, Volume= 0.097 af Outflow = 1.33 cfs @ 12.09 hrs, Volume= 0.097 af, Atten= 0%, Lag= 0.0 min Primary = 1.33 cfs @ 12.09 hrs, Volume= 0.097 af Routed to Pond P2 : DMH-2 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.84' @ 12.42 hrs Flood Elev= 50.00' Device Routing Invert Outlet Devices #1 Primary 44.40'15.0" Round Culvert L= 121.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 44.40' / 43.70' S= 0.0058 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=1.33 cfs @ 12.09 hrs HW=45.13' TW=44.65' (Dynamic Tailwater) 1=Culvert (Outlet Controls 1.33 cfs @ 2.58 fps) Pond P3: DMH-3 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=0.223 ac Peak Elev=46.84' 15.0" Round Culvert n=0.012 L=121.0' S=0.0058 '/' 1.33 cfs 1.33 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 24HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond P4: DMH-4 [80] Warning: Exceeded Pond CB-1 by 2.68' @ 14.44 hrs (4.41 cfs 0.295 af) [80] Warning: Exceeded Pond P6 by 0.08' @ 12.30 hrs (0.83 cfs 0.013 af) Inflow Area = 0.236 ac, 94.99% Impervious, Inflow Depth = 6.40" for 50-yr event Inflow = 1.58 cfs @ 12.08 hrs, Volume= 0.126 af Outflow = 1.58 cfs @ 12.08 hrs, Volume= 0.126 af, Atten= 0%, Lag= 0.0 min Primary = 1.58 cfs @ 12.08 hrs, Volume= 0.126 af Routed to Pond P1 : DMH-1 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.83' @ 12.41 hrs Flood Elev= 49.74' Device Routing Invert Outlet Devices #1 Primary 43.70'15.0" Round Culvert L= 65.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 43.70' / 43.20' S= 0.0077 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 1.23 sf Primary OutFlow Max=1.58 cfs @ 12.08 hrs HW=44.59' TW=44.33' (Dynamic Tailwater) 1=Culvert (Outlet Controls 1.58 cfs @ 2.36 fps) Pond P4: DMH-4 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=0.236 ac Peak Elev=46.83' 15.0" Round Culvert n=0.012 L=65.0' S=0.0077 '/' 1.58 cfs 1.58 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 25HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond P5: CHAMBERS Inflow Area = 0.618 ac, 86.84% Impervious, Inflow Depth = 5.82" for 50-yr event Inflow = 3.91 cfs @ 12.08 hrs, Volume= 0.300 af Outflow = 1.24 cfs @ 12.42 hrs, Volume= 0.300 af, Atten= 68%, Lag= 20.4 min Discarded = 0.22 cfs @ 11.16 hrs, Volume= 0.280 af Secondary = 1.02 cfs @ 12.42 hrs, Volume= 0.020 af Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.75' @ 12.41 hrs Surf.Area= 0.026 ac Storage= 0.111 af Flood Elev= 48.25' Surf.Area= 0.026 ac Storage= 0.111 af Plug-Flow detention time= 170.6 min calculated for 0.299 af (100% of inflow) Center-of-Mass det. time= 170.5 min ( 943.9 - 773.4 ) Volume Invert Avail.Storage Storage Description #1A 40.00' 0.045 af 28.50'W x 40.42'L x 6.75'H Field A 0.179 af Overall - 0.066 af Embedded = 0.113 af x 40.0% Voids #2A 40.75' 0.066 af ADS_StormTech MC-7200 +Cap x 15 Inside #1 Effective Size= 91.2"W x 60.0"H => 26.68 sf x 6.59'L = 175.9 cf Overall Size= 100.0"W x 60.0"H x 6.95'L with 0.36' Overlap 15 Chambers in 3 Rows Cap Storage= 39.5 cf x 2 x 3 rows = 237.0 cf 0.111 af Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #0 Secondary 46.75'Automatic Storage Overflow (Discharged without head) #1 Discarded 40.00'8.270 in/hr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=0.22 cfs @ 11.16 hrs HW=40.09' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.22 cfs) Secondary OutFlow Max=0.00 cfs @ 12.42 hrs HW=46.75' (Free Discharge) DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 26HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Pond P5: CHAMBERS Inflow Outflow Discarded Secondary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)4 3 2 1 0 Inflow Area=0.618 ac Peak Elev=46.75' Storage=0.111 af 3.91 cfs 1.24 cfs 0.22 cfs 1.02 cfs DEVELOPED CONDITIONS Type III 24-hr 50-yr Rainfall=6.98"25-0275DV00 Printed 1/14/2026Prepared by McClure Page 27HydroCAD® 10.20-7a s/n 12811 © 2025 HydroCAD Software Solutions LLC Summary for Pond P6: ADS DURASLOT TRENCH Inflow Area = 0.186 ac, 97.99% Impervious, Inflow Depth = 6.62" for 50-yr event Inflow = 1.27 cfs @ 12.08 hrs, Volume= 0.103 af Outflow = 1.27 cfs @ 12.08 hrs, Volume= 0.103 af, Atten= 0%, Lag= 0.0 min Primary = 1.27 cfs @ 12.08 hrs, Volume= 0.103 af Routed to Pond P4 : DMH-4 Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 46.84' @ 12.42 hrs Flood Elev= 49.70' Device Routing Invert Outlet Devices #1 Primary 44.23'12.0" Round Culvert L= 16.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 44.23' / 43.90' S= 0.0206 '/' Cc= 0.900 n= 0.012 Corrugated PP, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.27 cfs @ 12.08 hrs HW=44.93' TW=44.59' (Dynamic Tailwater) 1=Culvert (Outlet Controls 1.27 cfs @ 3.05 fps) Pond P6: ADS DURASLOT TRENCH Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=0.186 ac Peak Elev=46.84' 12.0" Round Culvert n=0.012 L=16.0' S=0.0206 '/' 1.27 cfs 1.27 cfs Appendix D: Pre-Development and Post- Development Plans BM1BM2HHFF: 52.48'FF: 52.48'IHEMGMMWMWWV WVGVEHWVRHWVDYHWVWVWVGV?MW?MWMWMWMWMW??MWMW?WVFF: 50.91'FF: 50.90'FF: 50.83'FF: 50.84'A/CGMBBA/CFF: 50.87'0 0 OHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHE00OHEOHEOHEOHEOHEOHE5050 50 51 50 50 5051 5251515151 5251 50 4 9 4950494 9 4 9 4950515150 495050504950505349 5050 50SSSSOHEOHEOHEOHEP:\2025000275-000\04-DRAWINGS\CIVIL\DRAINAGE\25-0275_DRN_EX.DWG REVISIONSPROJECT INFOENGINEERDRAWN BYCHECKED BYDRAWING NO.NOTICE:McClure Engineering Co. is notresponsible or liable for any issues,claims, damages, or losses(collectively, “Losses”) which arisefrom failure to follow these Plans,Specifications, and the engineeringintent they convey, or for Losseswhich arise from failure to obtainand/or follow the engineers’ orsurveyors' guidance with respect toany alleged errors, omissions,inconsistences, ambiguities, orconflicts contained withinthe Plans and Specifications.Ankeny,IA | Carroll,IACedar Rapids,IA | Clive,IACoralville,IA | Council Bluffs,IAFort Dodge,IA | Sioux City,IAColumbia,MO | Macon,MONorth Kansas City,MOLenexa, KSPortsmouth, NH | Boston, MA2025000275-000PROPOSED TACO BELL 433, 437, & 439 STATION AVENUE YARMOUTH, MA 02664DRN-1BLRBLRNID225 Friend Street Suite 805 Boston, MA 02114 P 617-466-6765########################10/10/2025PRE-DEVELOPED WATERSHED PLANS0202010 DRAINAGE LEGEND:1REX11POP-1EX-1OP-2OP-3OP-6OP-6OP-4EX-4EX-5EX-7EX-6EX-3EX-8OP-5 BM1BM2HHIHEMGMMWMWWV WVGVEHWVRHWVDYHWVWVWVGV?MW?MWMWMWMWMW??MWMW?WVA/CGMBBA/C0 0 OHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHEOHE00OHEOHEOHEOHEOHEOHESTSTST5050 50 51 50 50 5051 5251515151 5251 50 4 9 4950494 9 4 9 4950515150 495050504950505349 5050 50SSSSSTSTSTSTOHEOHEOHEOHERDRDRDRDPRO PO S ED T ACO B E L LRE S T AUR AN T ( SM A L L 2 0 ) 2 , 0 9 4 S F ( 2 0 S E A T S ) DR I V E THR U MOB I L E P IC K U P C 0 2 P:\2025000275-000\04-DRAWINGS\CIVIL\DRAINAGE\25-0275_DRN_DV.DWG REVISIONSPROJECT INFOENGINEERDRAWN BYCHECKED BYDRAWING NO.NOTICE:McClure Engineering Co. is notresponsible or liable for any issues,claims, damages, or losses(collectively, “Losses”) which arisefrom failure to follow these Plans,Specifications, and the engineeringintent they convey, or for Losseswhich arise from failure to obtainand/or follow the engineers’ orsurveyors' guidance with respect toany alleged errors, omissions,inconsistences, ambiguities, orconflicts contained withinthe Plans and Specifications.Ankeny,IA | Carroll,IACedar Rapids,IA | Clive,IACoralville,IA | Council Bluffs,IAFort Dodge,IA | Sioux City,IAColumbia,MO | Macon,MONorth Kansas City,MOLenexa, KSPortsmouth, NH | Boston, MA2025000275-000PROPOSED TACO BELL 433, 437, & 439 STATION AVENUE YARMOUTH, MA 02664DRN-2BLRBLRNID225 Friend Street Suite 805 Boston, MA 02114 P 617-466-6765########################10/10/2025DEVELOPED WATERSHED PLANS0202010 DRAINAGE LEGEND:1REX11POP-1S1S2S3S4S7S10S5S6S8S9OP-2OP-3OP-5OP-6P6CB-1P5P4P1P2P3CB-2CB-3CB-4CB-5 Appendix E: Post-Development Stormwater Inspection & Maintenance Manual Proposed Taco Bell Desert De Oro Foods, Inc. Map 88 Lot(s) 87 & 88 Yarmouth, Massachusetts Storm Water Management System Inspection and Maintenance Manual October 10th, 2025 08 I&M.doc Page 1 Introduction: The operation and maintenance of a storm water management system and its individual components is as critical to system performance as the design. Without proper maintenance, best management practices (BMPs) are likely to become functionally impaired or to fail, providing reduced or no treatment of storm water. Proper operation and maintenance will ensure that the storm water system and individual BMPs will remain effective at removing pollutants as designed and meeting New Hampshire’s water quality objectives. Proper maintenance will:  Maintain the volume of storm water treated over the long term;  Sustain the pollutant removal efficiency of the BMP;  Reduce the risk of re-suspending sediment and other pollutants captured by the BMP;  Prevent structural deterioration of the BMP and minimize the need for expensive repairs;  Decrease the potential for failure of the BMP. The NH Department of Environmental Services Alteration of Terrain (AoT) regulations (Env-Wq 1500) require the long-term maintenance of storm water practices and stipulate the establishment of a mechanism to provide for ongoing inspections and maintenance. Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 2 Facilities Information: Owner of Record: Desert De Oro Foods, Inc. 79 Main Street Mansfield, Ma 02048 Report Information:  Every effort has been made to provide a comprehensive operation and maintenance plan for this project. All measures and guidelines presented within this plan are the minimum efforts required to achieve the intent of the erosion and sedimentation control program and minimize off site impacts.  Should any omissions or inconsistencies arise in the plan, the owner, and governing officials are expected to use reasonable and experienced judgment in the field relative to evaluation and implementing measures based on the intent of this plan.  This manual does not preclude any requirements for additional controls identified in the approved plan set or support documents or any other appropriate techniques to limit erosion and sedimentation of the site.  Any measures deemed necessary by the town planning board, conservation commission, zoning board, or the town’s representative shall become part of this inspection and maintenance plan.  Desert De Oro Foods, Inc. will be responsible for implementing the required reporting, inspection, and maintenance activities identified in this Inspection and Maintenance (I&M) manual.  Desert De Oro Foods, Inc. shall maintain all record keeping required by the I&M manual. Any transfer of responsibility for I&M activities or transfer in ownership shall be documented to the DES in writing.  Inspection and maintenance reports shall be completed after each inspection. Copies of the report forms to be completed by the inspector are attached at the end of this manual, including: o Inspection checklist to be used during each inspection; o Inspection and maintenance logs to document each inspection and maintenance activity;  A plan showing the locations of all the storm water practices described in the I&M manual is attached at the end of this manual.  Inspection and maintenance records must be provided to DES upon request. Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 3 Storm water management systems present at Proposed Taco Bell Description: The project will consist of a closed drainage system made up of Deep Sump Catch Basins, a Trench Drain, and a Subsurface Stormtech Chamber system. Maintenance: 1. Regular inspection and routine maintenance are necessary to ensure that the storm water management system continues to control and treat runoff. 2. Structural components of the site’s drainage system must be inspected and maintained on an annual basis (minimum). 3. The outlets of the storm water management system must be inspected bi-annually. 4. All outfalls shall be cleaned of all siltation and debris at the completion of the construction process when the site has been stabilized with loam, seed, and landscaping. 5. Any evidence of erosion, structural damage to the outlet, or other damage must be reported to the appropriate on-site representative and repaired as soon as possible. 6. Any sediment and/or trash should be removed from the outlet structures and pipes cleaned of all silt. 7. Subsurface pipe detention systems must be inspected and maintained on an annual basis (minimum). Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 4 Page Intentionally Left Blank Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 5 Underground Infiltration Basin Description: Infiltration basins are structures designed to temporarily store runoff, allowing all or a portion of the water to infiltrate into the ground. The structure is designed to completely drain between storm events. An underground infiltration basin is specifically designed to retain and infiltrate the entire Water Quality Volume. Some infiltration basins may infiltrate additional volumes during larger storm events, but many will be designed to release stormwater exceeding the water quality volume from the larger storms. In a properly sited and designed infiltration basin, water quality treatment is provided by runoff pollutants binding to soil particles beneath the basin as water percolates into the subsurface. Biological and chemical processes occurring in the soil also contribute to the breakdown of pollutants. Infiltrated water is recharged to the underlying groundwater. Subsurface infiltration basins may comprise a subsurface manifold system with associated crushed stone storage bed, or specially-designed chambers (with or without perforations) bedded in or above crushed stone. Maintenance: 1. Removal of debris from inlet and outlet structures 2. Removal of accumulated sediment 3. Inspection and repair of outlet structures and appurtenances 4. Inspection of infiltration components at least twice annually and following any rainfall event exceeding 2.5 inches in a 24 hour period, with maintenance or rehabilitation conducted as warranted by such inspection. 5. Inspection of pretreatment measures at least twice annually, and removal of accumulated sediment as warranted by inspection, but no less than once annually. 6. If an infiltration system does not drain within 72-hours following a rainfall event, then a qualified professional should assess the condition of the facility to determine measures required to restore infiltration function, including but not limited to removal of accumulated sediments or reconstruction of the infiltration trench. Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 6 Inspection Checklist and Maintenance Report Underground Infiltration Basin Practice Location: Date: Performed By: Signature Inspection Checklist Presence of woody vegetation on embankments  Yes  No Presence of trash or debris  Yes  No Presence of accumulated sediment  Yes  No Structural damage at inlet or outlet  Yes  No Drains with 72 hours of rainfall  Yes  No Maintenance Performed Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 7 Deep-Sump Catch Basins Description: A deep sump catch basin consists of a manhole-type structure with an inlet grate, an outlet pipe connected to the piped drainage system, and a sump with a depth several times the diameter of the outlet pipe. The inlet grate is located at the surface and is sometimes combined with a vertical inlet integrated with a street or parking area curb. The sump’s purpose is to capture coarse sediments and debris from the runoff intercepted by the structure. The outlet pipe can be fitted with a “hood” consisting of a cast metal or formed plastic fitting, designed to prevent floating materials from exiting the structure. Deep sump catch basins used as pretreatment are most effective if sited “off-line” since flow-through basins are more susceptible to sediment re-suspension. The outlet hood provides benefits for trapping floating trash, as well as for short-term spill containment. Maintenance: 1. Catch basins may require frequent maintenance. Depending on location, this may require several cleanings of the sumps each year. At a minimum, it is recommended that catch basins be inspected at least twice annually, once following snow-melt and once following leaf-drop and cleaned as indicated by inspection. 2. Sediment should be removed when it approaches half the sump depth. 3. If floating hydrocarbons are observed during an inspection, the material should be removed immediately by skimming, absorbent materials, or other method and disposed in conformance with applicable state and federal regulations. 4. Cleaning may require Vacuum-truck instead of “clam-shell” to avoid damage to hood. 5. Damaged hoods should be replaced when noted by inspection Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 8 Inspection Checklist and Maintenance Report Deep-Sump Catch Basins Practice Location: Date: Performed By: Signature Inspection Checklist Presence of erosion or vegetation loss  Yes  No Presence of accumulated sediment  Yes  No Presence of trash or debris  Yes  No Maintenance Performed Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 9 Page Intentionally Left Blank Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 10 Deicing Log Access Drives & Parking Areas Do Not Apply Sand To Permeable Pavements Date: Performed By: Signature Maintenance Performed: Air Temperature Pavement Temperature Relative Humidity Dew Point Sky Reason for applying: Chemical: Application Time: Application Amount: Observation (first day): Observation (after event): Observation (before next application): Proposed Taco Bell October 10th, 2025 Storm Water Management System: Inspection and Maintenance Manual 08 I&M.doc Page 11 Inspection and Maintenance Log BMP Inspection Date Inspected By Maintenance Required? Maintenance Performed 1 Yes No 2 Yes No 3 Yes No 4 Yes No 5 Yes No 6 Yes No 7 Yes No 8 Yes No 9 Yes No