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HomeMy WebLinkAboutSWM Report Composite Revised Stormwater Management Report for Proposed Contractor Bays 212 Mid-Tech Drive West Yarmouth, Massachusetts Prepared for: Turtle Rock, LLC 222 Willow Street Yarmouthport, MA 02675 August 31, 2021 Revised October 6, 2022 BAXTER NYE ENGINEERING & SURVEYING Registered Professional Engineers, Land Surveyors & Scientists 1597 Falmouth Road, Centerville, MA 02632 Tel: 508-771-7502 ■ Fax: 508-771-7622 ■ www.baxter-nye.com STORMWATER MANAGEMENT REPORT TABLE OF CONTENTS 1. Cover Sheet 2. Table of Contents 3. Project Narrative 4. Table 1 - Peak Discharge and Volume Release 5. TSS Removal Calculation 6. Recharge to Groundwater Volume, Water Quality Volume, and Drawdown Calculations (no modification to drawdown calculations) 7. Pre and Post Development Drainage Area Plans, sheets C4.2 and C4.3 8. 2, 10, 25, 50, and 100 year Pre-Development HydroCad Calculations 9. 2, 10, 25, 50, and 100 year Post-Development HydroCad Calculations 10. Stormwater Operations, Maintenance and Inspections Plan with SMS Inspection Form Checklist 11. Checklist for Stormwater Report (Not included, no modifications) 12. Site Soil Data (Not included, but Table 2.3.2 1982 Rawls Rates added) 13. Notice To Abutters, Abutters List (Not included, no modifications) 14. Site Plan Review Comments (Not included, no modifications) 15. Adminstrative Checklist for Stormwater Management Permit Application (Not included, no modifications) 16. High Groundwater Level Computation and GW Contour Map BAXTER NYE ENGINEERING & SURVEYING SWM Report Narrative 2021-036 212 Mid-Tech Drive SWM Narrative .docx Prepared for: Turtle Rock, LLC Yarmouthport, Massachusetts Site Redevelopment - Project Narrative Proposed Contractor Bays Building 212 Mid-Tech Drive, West Yarmouth, MA (Map 84 – Parcel 12) 1.0 Introduction / Summary The project applicant, Turtle Rock, LLC, owns the 1.4-acre property and office building located at 212 Mid-Tech Drive in West Yarmouth (the Site). The applicant proposes to demolish the existing office building and construct an 11, 360 sf contractor bays building in the middle of the site, and a proposed paved parking lot at the front of the site along Mid-Tech Drive. Baxter Nye Engineering & BAXTER NYE ENGINEERING & SURVEYING SWM Report Narrative 2021-036 212 Mid-Tech Drive SWM Narrative .docx Surveying (BN) has prepared an existing condition plan and proposed site plans designed to meet the requirements of the Stormwater Management Regulations. The proposed site work will disturb approximately 50,400 sf, and therefore, since greater than one acre (43,560 sf), requires a Stormwater Management Permit from the Yarmouth Conservation Commission. Existing Site Conditions Geographical Setting and Wetland Resource Areas The property, on which a two-story office building currently sits, is located near the end of Mid- Tech Drive, where a paved cul de sac exists. The road is fully developed with commercial business-type buildings and property uses. The abutting properties to the north and south are developed with commercial buildings, as are the lots across Mid-Tech Drive. The property to the east is a large fully wooded property owned by Town of Yarmouth for Water Department use. The site contains no wetland resource areas, nor flood zones. The site lies within the Yarmouth Aquifer Protection District, which is considered a critical area. The only trigger for a Stormwater Management Permit is the greater than one acre of site disturbance threshold that will be exceeded, therefore the application to Yarmouth Conservation Commission. Existing drainage at the site consists of a series of leaching catch basins within the paved parking areas, connected with perforated 12” CPP pipes within stone trenches, per Site Plan of Land by Weller & Associates, datefd November 4, 1998. These leaching structures are to be removed with the redevelopment of the site. The existing drainage at the site is shown as four subcatchment areas and four design points, which are shown on the attached Pre-Development Drainage Areas Plan, sheet C4.2. The existing drainage analysis was performed with these leaching structures modeled as 6’ diameter, 6’ deep precast concrete basins with four feet of stone surrounding each basin. No volume or exfiltration was accounted for in the 12” diameter pipes with ¾” to 1-1/2” crushed stone joining each basin. Proposed Work The proposed project consists of demolition of the existing two-story building and constructing an 11,360 sf single-story contractor bays building with overhead doors in front of each unit. The building will be served by town water, underground utilities, and a new septic system. Interior floor drains will be piped to a dual containment industrial wastewater holding tank. Parking for the site will be paved with bituminous concrete and will be landscaped with trees and shrubs. Stormwater from the building will be collected with gutters and downspouts and routed with CPP pipe to three pre-treatment areas, which treat the runoff for water quality prior to infiltrating in underground Cultec Recharger units. Stormwater from the parking lot will flow to low point curb openings to sediment forebay pre-treatment areas. Beehive-grated catch basins will be installed 6” BAXTER NYE ENGINEERING & SURVEYING SWM Report Narrative 2021-036 212 Mid-Tech Drive SWM Narrative .docx above the bottom of the forebays, where water will enter the catch basins for conveyance to the Cultec Rechargers. The catch basins will be equipped with deep sumps and oil/gas hoods to provide further treatment and removal of TSS. Calculations included with this report show that 44% of the total suspended solids in the stormwater (TSS) will be removed prior to infiltration, and 89% overall. Drainage subcatchment areas are shown on the attached Post-Development Drainage Areas Plan, sheet C4.3. Underground Cultec 330XL HD Recharger Units will be used for infiltration of stormwater at the site. Soil testing at the site and US SCS mapping show sandy soils for the site, and the Rawls Rate of 8.27 inches per hour was used for Sandy soils. Confirmatory test pits at time of installation will be used to verify consistency of soils at drainage system locations. The existing Cultec system installed in 2017 at the south end of the site will remain, the front forebay and beehive catch basin will be removed. The rear beehive catch basin will remain, with that forebay proposed to be expanded for Water Quality Volume with the new development. Proposed impervious coverage at the site will be approximately 37,100 sf, including the building, paved areas, and concrete pads at the rear of each unit. This total is a reduction from the 38,700 sf of impervious coverage which currently exists at the site. All drainage facilities and stormwater will be maintained on-site. No easements are proposed. One electric easement is shown on the existing conditions plan, 10 feet wide across the entire front of the lot. Sequence of Construction · Install silt fencing/hay bales to establish the limit of work as shown on plan. · Construct temporary construction entrances at points of egress from the site during construction. · Discharges from dewatering of excavations shall not be diverted directly into any existing or proposed storm drains without pretreatment via settling basins. · Install haybale check dams along center of swales at 50' 0.c., as necessary. · Clear and grub site within the limit of work. · Construct SWM bioswales to within 1 ft of final bottom elevation. Basin to be used as sediment trap. · Establish rough subgrades for parking lot and building platform. · Demolish existing building and load demolition debris in trucks and haul away. · Perform building and site construction. Install base course paving as soon as practical. · Inspect and maintain erosion control measures after rainfall events and a minimum of once per week. · Remove sediment buildup at erosion control devices as needed. Redistribute material over site in conformance with earthwork specifications. BAXTER NYE ENGINEERING & SURVEYING SWM Report Narrative 2021-036 212 Mid-Tech Drive SWM Narrative .docx · Once all drainage structures are installed, install filter fabric and stone or haybales around all new structures and maintain them until pavement is in place and vegetation is established. All outfalls shall be stabilized with stone protection as required. · All cut and fill slopes shall be temporarily stabilized with topsoil, seed and mulch or Curlex erosion control blanket, as required if construction activity ceases on said slopes for a period of 14 days or greater. All slopes shall be permanently stabilized as required immediately upon completion of final grading. · Provide silt fence for bioswale infiltration protection. Bioswale areas shall be protected at all times from construction traffic and sediment during construction. · Complete finish grading and stabilization of site. Place final paving course. · Remove sediment from all drainage structures, catch basins, and pipes after completion of construction. Remove and regrade temporary berms, swales, check dams, etc. Stabilize disturbed areas. · Clean out all sediment from SWM basins and outlet structures. Regrade to contours per design. Install final bioswale cross section materials in stormwater management facilities. Stabilize all slopes as required. · Upon establishment of permanent ground cover and approval by the engineer, remove haybales & silt fence. Stabilize all areas where haybales were removed. Stormwater Management Performance Standards (1) Project is a redevelopment project that reduces the amount of impervious coverage on the site from existing conditions. All roof runoff will be pre-treated prior to infiltration. Trees will be planted throughout site to intercept rainfall. All runoff from paved surfaces will be pre-treated with 44% TSS removal rate. (2) Good housekeeping measures have been added to the O&M Plan. Car washing will not be allowed inside or outside building. Sediment, debris, leaf litter, and organic debris will be removed from all drainage facilities per maintenance schedule in O&M Plan. Fertilizer use will adhere to restrictions in Yarmouth Stormwater Management Regulations. Inspections of SWM facilities will be done per O&M Plan. (3) Post-development peak discharges and volumes do not exceed pre-development peak rates and volumes for all storm events. Pre-treatment for infiltration devices will remove 44% TSS prior to infiltration. All runoff from the proposed metal roof will be through pre- treatment prior to infiltration. All runoff calculations were based on NOAA Atlas 14 precipitation data. (4) N/A (5) Average annual TSS removal for post-construction is 89%.with street sweeping, sediment forebay (bioswale), deep sump catch basin, and infiltration basin. Average annual post- construction Total Phosphorus removal will be 60 to 70%, based on Pollutant Removal BAXTER NYE ENGINEERING & SURVEYING SWM Report Narrative 2021-036 212 Mid-Tech Drive SWM Narrative .docx Efficiencies per DEP Stormwater Management Policy Structural BMP for infiltration basin and pre-treatment. Average annual post-construction Total Nitrogen removal will be 50 to 60%, based on based on Pollutant Removal Efficiencies per DEP Stormwater Management Policy Structural BMP for infiltration basin and pre-treatment. (6) N/A (7) N/A Summary BN believes that the stormwater management systems designed for the site meet all Town of Yarmouth and Commonwealth of Massachusetts requirements for stormwater management during construction and post-construction phases for the project. BN also believes that with the stormwater measures proposed, that the project does serve the stated interests of the Town of Yarmouth Stormwater Management Regulations and that this project is eligible for a Stormwater Management permit from the Yarmouth Conservation Commission, as all applicable standards are met. BAXTER NYE ENGINEERING & SURVEYING 78 North Street, 3rd Floor ■ Hyannis, MA 02601 Tel: 508-771-7502 ■ Fax: 508-771-7622 ■ www.baxter-nye.com TABLE 1: PEAK DISCHARGE AND VOLUME RELEASE STORM (YEAR) STUDY POINT PRE-DEVELOPMENT POST DEVELOPMENT PEAK DISCHARGE (cfs) VOLUME (ac-ft) PEAK DISCHARGE (cfs) VOLUME (ac-ft) 2 SP1 0.00 0.000 0.00 0.000 SP3 0.01 0.004 0.01 0.003 SP4 0.00 0.000 0.00 0.000 10 SP1 0.00 0.000 0.00 0.000 SP3 0.12 0.016 0.09 0.009 SP4 0.00 0.000 0.00 0.000 25 SP1 0.00 0.000 0.00 0.000 SP3 0.29 0.028 018 0.015 SP4 0.00 0.000 0.00 0.000 50 SP1 0.00 0.000 0.00 0.000 SP3 0.58 0.043 0.25 0.019 SP4 0.00 0.001 0.00 0.001 100 SP1 0.00 0.000 0.00 0.000 SP3 1.47 0.074 0.49 0.031 SP4 0.00 0.001 0.00 0.001 Site Redevelopment186 & 212 Mid-Tech Drive, West Yarmouth, MAProject # 2021-03610/4/2022TSS REMOVAL CALCULATION WORKSHEETA B C D EBMP TSS Removal Rate Starting TSS Load * Amount Removed Remaining Load(BxC)(C-D)Sediment Forebay (Bioswale) 25% 1.00 0.25 0.75Deep Sump Catch Basin 25% 0.75 0.19 0.56Infiltration Basin80% 0.56 0.45 0.11Total TSS Removed = 0.89*Equals remaining load from previous BMP (E)Baxter Nye Engineering2021-036 TSS Removal Spreadsheet.xls Date: 2022-10-06 Job #: 2021-036 Job Name: 212 Mid-Tech Drive Calculations by: JKL RECHARGE TO GROUNDWATER VOLUME (MADEP Standard 3) All site soils within area of proposed impervious cover are HSG A. Therefore, the recharge rate is: 0.6” x total impervious area. The underground Infiltration SWM Facilities are used for recharge and quantity control for post- development site runoff. 1) Cultec System 1: Required volume: 0.6” x 0.416 ac = 906 cf Infiltration Storage Volume Provided to top of Cultec system: = 1,789 cf > 906 cf. OK 2) Cultec System 2: Required volume: 0.6” x 0.289 ac = 629 cf Infiltration Storage Volume Provided to top of Cultec system: = 1,110 cf > 629 cf. OK 3) Existing Cultec System 3: Required volume: 0.6” x 0.116 ac = 253 cf Infiltration Storage Volume Provided to top of Cultec system: = 1,789 cf > 253 cf. OK Therefore, design requirement for recharge has been met. The Volume of Recharge well exceeds the required amount of recharge. WATER QUALITY VOLUME CALCULATIONS (MADEP Standard 4-6) The site is in a Zone II Recharge Area, which is defined as a Critical Area. Therefore, the Water Quality Treatment must address the first one (1) inch of runoff over the total impervious area. On-site impervious area proposed is 0.822 acres. The proposed building roof area is 0.260 acres, which is conveyed to the SWM facilities, therefore included in impervious area. The total impervious area to receive water quality treatment is 0.822 acres. WQV = 1.0 “ x (acres of impervious area) = 1.0” x (0.822 acres) = 0.822 acre-inches = 0.822/12 in/ft = 0.0685 acre-feet = 0..0685 acre-feet x 43,560 sf/ac = 2,984+/- cf The total WQV to be treated through BMP’s is 2,984 cf. BMP’s used: All the runoff from the impervious areas passes through the SWM facilities with pretreatment sediment forebays prior to entering the beehives and Cultec 330 Recharger units. NOTE: See attached Excel spreadsheet for Forebay Volumes provided. 1) Sediment Forebay 1: WQV Required: 0.416 ac x 43,560 x 1” = 1,510 cf Water Quality Storage Volume Provided up to elevation 46.0 = 1.731 cf OK 2) Sediment Forebay 2: WQV Required: 0.289 ac x 43,560 x 1” = 1,049 cf Water Quality Storage Volume Provided up to elevation 45.35 1,101 cf 3) Existing Sediment Forebay 3: WQV Required: 0.116 ac x 1” = 421 cf Water Quality Storage Volume Provided up to elevation 46.36 = 674 cf OK The combined BMP treatments are designed in accordance with the MDEP sizing requirements and provide the Water Quality Volume requirements. MID-TECH DRIVEBAXTER NYEENGINEERING &SURVEYINGJDB 212 Mid-Tech Drive, LLCc/o Turtle Rock, LLC231 Willow StreetYarmouthport, MA 02675Site Redevelopment186 & 212 Mid-Tech DriveWest Yarmouth, MA 02673FOR PERMIT ONLY - NOT FOR CONSTRUCTIONSHEET TITLEDATE:CHECKED BY:JOB NO:DRAWN BY:DESCRIPTIONDATEPREPARED FOR:PROJECT TITLESHEET NOSCALE:STAMPCONSULTANTFILE:CONSULTANTSTAMPCOPYRIGHT c 2021, BY SMART ENGINEERING LLC, dba BAXTER NYE ENGINEERING & SURVEYING, ALL RIGHTS RESERVED. REPRODUCTION IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE COPYRIGHT HOLDER IS PROHIBITEDC4.2Pre-Devt DrainageAreas PlanO:\2021\2021-036\CIVIL\PLOT\2021-036 DA PRE.dwg, 10/6/2022 8:49:58 AM, jlavelle, DWG To PDF.pc3, ARCH expand D (24.00 x 36.00 Inches), 1:1 MID-TECH DRIVEBAXTER NYEENGINEERING &SURVEYINGJDB 212 Mid-Tech Drive, LLCc/o Turtle Rock, LLC231 Willow StreetYarmouthport, MA 02675Site Redevelopment186 & 212 Mid-Tech DriveWest Yarmouth, MA 02673FOR PERMIT ONLY - NOT FOR CONSTRUCTIONSHEET TITLEDATE:CHECKED BY:JOB NO:DRAWN BY:DESCRIPTIONDATEPREPARED FOR:PROJECT TITLESHEET NOSCALE:STAMPCONSULTANTFILE:CONSULTANTSTAMPCOPYRIGHT c 2021, BY SMART ENGINEERING LLC, dba BAXTER NYE ENGINEERING & SURVEYING, ALL RIGHTS RESERVED. REPRODUCTION IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE COPYRIGHT HOLDER IS PROHIBITEDC4.3Post-Devt DrainageAreas PlanO:\2021\2021-036\CIVIL\PLOT\2021-036 DA POST.dwg, 10/6/2022 11:52:53 AM, jlavelle, DWG To PDF.pc3, ARCH expand D (24.00 x 36.00 Inches), 1:1 DA-1 Site Areas to Beehives/C\ultec 330s DA-2 Site Areas to LB's DA-3 Site Areas to Road DA-4 Area to north SP1 Study Point 1 SP3 Study Point 3 SP4 Study Point #4 1P Cultec 330 Infiltration Chamber with Forebays 2P Existing LB's Routing Diagram for 2021-036 PRE-DEVT Prepared by {enter your company name here}, Printed 10/6/2022 HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Subcat Reach Pond Link 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 2HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Area = 0.332 ac, 96.99% Impervious, Inflow Depth > 2.91" for 2-Year event Inflow = 1.09 cfs @ 12.07 hrs, Volume= 0.080 af Outflow = 0.19 cfs @ 12.51 hrs, Volume= 0.080 af, Atten= 82%, Lag= 26.5 min Discarded = 0.19 cfs @ 12.51 hrs, Volume= 0.080 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 43.79' @ 12.51 hrs Surf.Area= 802 sf Storage= 956 cf Plug-Flow detention time= 30.3 min calculated for 0.080 af (100% of inflow) Center-of-Mass det. time= 30.2 min ( 805.5 - 775.3 ) Volume Invert Avail.Storage Storage Description #1 44.00' 4,299 cf Custom Stage Data (Conic) Listed below (Recalc) x 2 #2A 42.07' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #3A 42.57' 1,088 cf Cultec R-330XLHD x 20 Inside #2 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 6,088 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 84 0 0 84 45.00 233 152 152 239 46.00 451 336 488 467 47.00 1,459 907 1,395 1,480 47.35 2,936 754 2,150 2,958 Device Routing Invert Outlet Devices #1 Discarded 42.07'8.270 in/hr Exfiltration over Wetted area from 42.06' - 99.61' Excluded Wetted area = 0 sf #2 Primary 47.02'10.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.19 cfs @ 12.51 hrs HW=43.79' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=42.07' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 3HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)1 0 Inflow Area=0.332 ac Peak Elev=43.79' Storage=956 cf 1.09 cfs 0.19 cfs0.19 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 4HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing LB's Inflow Area = 0.704 ac, 78.55% Impervious, Inflow Depth = 1.91" for 2-Year event Inflow = 1.63 cfs @ 12.08 hrs, Volume= 0.112 af Outflow = 0.38 cfs @ 12.48 hrs, Volume= 0.112 af, Atten= 77%, Lag= 24.4 min Discarded = 0.38 cfs @ 12.48 hrs, Volume= 0.112 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 40.84' @ 12.48 hrs Surf.Area= 1,176 sf Storage= 1,285 cf Plug-Flow detention time= 24.5 min calculated for 0.112 af (100% of inflow) Center-of-Mass det. time= 24.5 min ( 847.2 - 822.7 ) Volume Invert Avail.Storage Storage Description #1 38.50' 2,650 cf 14.00'W x 14.00'L x 6.50'H Prismatoid x 6 7,644 cf Overall - 1,018 cf Embedded = 6,626 cf x 40.0% Voids #2 39.00' 1,018 cf 6.00'D x 6.00'H Vertical Cone/Cylinder x 6 Inside #1 #3 47.40' 623 cf Custom Stage Data (Conic) Listed below (Recalc) 4,291 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 47.40 4 0 0 4 48.00 3,000 623 623 3,001 Device Routing Invert Outlet Devices #1 Discarded 38.50'8.270 in/hr Exfiltration over Wetted area from 38.40' - 45.00' Excluded Wetted area = 0 sf #2 Primary 47.88'10.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height Discarded OutFlow Max=0.38 cfs @ 12.48 hrs HW=40.83' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.38 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=38.50' (Free Discharge) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 5HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 2P: Existing LB's Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)1 0 Inflow Area=0.704 ac Peak Elev=40.84' Storage=1,285 cf 1.63 cfs 0.38 cfs0.38 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 6HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Area = 0.332 ac, 96.99% Impervious, Inflow Depth > 4.39" for 10-Year event Inflow = 1.61 cfs @ 12.07 hrs, Volume= 0.122 af Outflow = 0.28 cfs @ 12.52 hrs, Volume= 0.122 af, Atten= 83%, Lag= 26.8 min Discarded = 0.28 cfs @ 12.52 hrs, Volume= 0.122 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 44.64' @ 12.52 hrs Surf.Area= 1,144 sf Storage= 1,598 cf Plug-Flow detention time= 44.0 min calculated for 0.121 af (100% of inflow) Center-of-Mass det. time= 43.8 min ( 812.8 - 768.9 ) Volume Invert Avail.Storage Storage Description #1 44.00' 4,299 cf Custom Stage Data (Conic) Listed below (Recalc) x 2 #2A 42.07' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #3A 42.57' 1,088 cf Cultec R-330XLHD x 20 Inside #2 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 6,088 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 84 0 0 84 45.00 233 152 152 239 46.00 451 336 488 467 47.00 1,459 907 1,395 1,480 47.35 2,936 754 2,150 2,958 Device Routing Invert Outlet Devices #1 Discarded 42.07'8.270 in/hr Exfiltration over Wetted area from 42.06' - 99.61' Excluded Wetted area = 0 sf #2 Primary 47.02'10.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.28 cfs @ 12.52 hrs HW=44.64' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.28 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=42.07' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 7HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)1 0 Inflow Area=0.332 ac Peak Elev=44.64' Storage=1,598 cf 1.61 cfs 0.28 cfs0.28 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 8HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing LB's Inflow Area = 0.704 ac, 78.55% Impervious, Inflow Depth = 3.29" for 10-Year event Inflow = 2.77 cfs @ 12.07 hrs, Volume= 0.193 af Outflow = 0.53 cfs @ 12.52 hrs, Volume= 0.193 af, Atten= 81%, Lag= 26.4 min Discarded = 0.53 cfs @ 12.52 hrs, Volume= 0.193 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 43.17' @ 12.52 hrs Surf.Area= 1,176 sf Storage= 2,624 cf Plug-Flow detention time= 41.3 min calculated for 0.193 af (100% of inflow) Center-of-Mass det. time= 41.3 min ( 848.5 - 807.2 ) Volume Invert Avail.Storage Storage Description #1 38.50' 2,650 cf 14.00'W x 14.00'L x 6.50'H Prismatoid x 6 7,644 cf Overall - 1,018 cf Embedded = 6,626 cf x 40.0% Voids #2 39.00' 1,018 cf 6.00'D x 6.00'H Vertical Cone/Cylinder x 6 Inside #1 #3 47.40' 623 cf Custom Stage Data (Conic) Listed below (Recalc) 4,291 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 47.40 4 0 0 4 48.00 3,000 623 623 3,001 Device Routing Invert Outlet Devices #1 Discarded 38.50'8.270 in/hr Exfiltration over Wetted area from 38.40' - 45.00' Excluded Wetted area = 0 sf #2 Primary 47.88'10.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height Discarded OutFlow Max=0.53 cfs @ 12.52 hrs HW=43.17' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.53 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=38.50' (Free Discharge) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 9HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 2P: Existing LB's Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)3 2 1 0 Inflow Area=0.704 ac Peak Elev=43.17' Storage=2,624 cf 2.77 cfs 0.53 cfs0.53 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 10HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Area = 0.332 ac, 96.99% Impervious, Inflow Depth > 5.32" for 25-Year event Inflow = 1.94 cfs @ 12.07 hrs, Volume= 0.147 af Outflow = 0.33 cfs @ 12.52 hrs, Volume= 0.147 af, Atten= 83%, Lag= 27.1 min Discarded = 0.33 cfs @ 12.52 hrs, Volume= 0.147 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 45.15' @ 12.52 hrs Surf.Area= 1,325 sf Storage= 2,021 cf Plug-Flow detention time= 50.9 min calculated for 0.147 af (100% of inflow) Center-of-Mass det. time= 50.7 min ( 817.3 - 766.6 ) Volume Invert Avail.Storage Storage Description #1 44.00' 4,299 cf Custom Stage Data (Conic) Listed below (Recalc) x 2 #2A 42.07' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #3A 42.57' 1,088 cf Cultec R-330XLHD x 20 Inside #2 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 6,088 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 84 0 0 84 45.00 233 152 152 239 46.00 451 336 488 467 47.00 1,459 907 1,395 1,480 47.35 2,936 754 2,150 2,958 Device Routing Invert Outlet Devices #1 Discarded 42.07'8.270 in/hr Exfiltration over Wetted area from 42.06' - 99.61' Excluded Wetted area = 0 sf #2 Primary 47.02'10.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.33 cfs @ 12.52 hrs HW=45.15' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.33 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=42.07' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 11HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)2 1 0 Inflow Area=0.332 ac Peak Elev=45.15' Storage=2,021 cf 1.94 cfs 0.33 cfs0.33 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 12HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing LB's Inflow Area = 0.704 ac, 78.55% Impervious, Inflow Depth = 4.19" for 25-Year event Inflow = 3.49 cfs @ 12.07 hrs, Volume= 0.246 af Outflow = 0.63 cfs @ 12.52 hrs, Volume= 0.246 af, Atten= 82%, Lag= 27.0 min Discarded = 0.63 cfs @ 12.52 hrs, Volume= 0.246 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 44.73' @ 12.52 hrs Surf.Area= 1,176 sf Storage= 3,516 cf Plug-Flow detention time= 49.5 min calculated for 0.246 af (100% of inflow) Center-of-Mass det. time= 49.4 min ( 849.9 - 800.5 ) Volume Invert Avail.Storage Storage Description #1 38.50' 2,650 cf 14.00'W x 14.00'L x 6.50'H Prismatoid x 6 7,644 cf Overall - 1,018 cf Embedded = 6,626 cf x 40.0% Voids #2 39.00' 1,018 cf 6.00'D x 6.00'H Vertical Cone/Cylinder x 6 Inside #1 #3 47.40' 623 cf Custom Stage Data (Conic) Listed below (Recalc) 4,291 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 47.40 4 0 0 4 48.00 3,000 623 623 3,001 Device Routing Invert Outlet Devices #1 Discarded 38.50'8.270 in/hr Exfiltration over Wetted area from 38.40' - 45.00' Excluded Wetted area = 0 sf #2 Primary 47.88'10.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height Discarded OutFlow Max=0.63 cfs @ 12.52 hrs HW=44.73' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.63 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=38.50' (Free Discharge) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 13HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 2P: Existing LB's Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)3 2 1 0 Inflow Area=0.704 ac Peak Elev=44.73' Storage=3,516 cf 3.49 cfs 0.63 cfs0.63 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 14HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Area = 0.332 ac, 96.99% Impervious, Inflow Depth > 6.02" for 50 Year event Inflow = 2.19 cfs @ 12.07 hrs, Volume= 0.167 af Outflow = 0.36 cfs @ 12.53 hrs, Volume= 0.167 af, Atten= 83%, Lag= 27.3 min Discarded = 0.36 cfs @ 12.53 hrs, Volume= 0.167 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 45.51' @ 12.53 hrs Surf.Area= 1,471 sf Storage= 2,347 cf Plug-Flow detention time= 55.3 min calculated for 0.167 af (100% of inflow) Center-of-Mass det. time= 55.1 min ( 820.4 - 765.3 ) Volume Invert Avail.Storage Storage Description #1 44.00' 4,299 cf Custom Stage Data (Conic) Listed below (Recalc) x 2 #2A 42.07' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #3A 42.57' 1,088 cf Cultec R-330XLHD x 20 Inside #2 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 6,088 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 84 0 0 84 45.00 233 152 152 239 46.00 451 336 488 467 47.00 1,459 907 1,395 1,480 47.35 2,936 754 2,150 2,958 Device Routing Invert Outlet Devices #1 Discarded 42.07'8.270 in/hr Exfiltration over Wetted area from 42.06' - 99.61' Excluded Wetted area = 0 sf #2 Primary 47.02'10.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.36 cfs @ 12.53 hrs HW=45.51' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.36 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=42.07' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 15HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)2 1 0 Inflow Area=0.332 ac Peak Elev=45.51' Storage=2,347 cf 2.19 cfs 0.36 cfs0.36 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 16HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing LB's Inflow Area = 0.704 ac, 78.55% Impervious, Inflow Depth > 4.88" for 50 Year event Inflow = 4.04 cfs @ 12.07 hrs, Volume= 0.286 af Outflow = 1.04 cfs @ 12.44 hrs, Volume= 0.286 af, Atten= 74%, Lag= 22.0 min Discarded = 0.64 cfs @ 12.26 hrs, Volume= 0.281 af Primary = 0.40 cfs @ 12.44 hrs, Volume= 0.005 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 47.93' @ 12.44 hrs Surf.Area= 3,497 sf Storage= 4,092 cf Plug-Flow detention time= 53.2 min calculated for 0.286 af (100% of inflow) Center-of-Mass det. time= 53.1 min ( 849.3 - 796.2 ) Volume Invert Avail.Storage Storage Description #1 38.50' 2,650 cf 14.00'W x 14.00'L x 6.50'H Prismatoid x 6 7,644 cf Overall - 1,018 cf Embedded = 6,626 cf x 40.0% Voids #2 39.00' 1,018 cf 6.00'D x 6.00'H Vertical Cone/Cylinder x 6 Inside #1 #3 47.40' 623 cf Custom Stage Data (Conic) Listed below (Recalc) 4,291 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 47.40 4 0 0 4 48.00 3,000 623 623 3,001 Device Routing Invert Outlet Devices #1 Discarded 38.50'8.270 in/hr Exfiltration over Wetted area from 38.40' - 45.00' Excluded Wetted area = 0 sf #2 Primary 47.88'10.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height Discarded OutFlow Max=0.64 cfs @ 12.26 hrs HW=47.65' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.64 cfs) Primary OutFlow Max=0.32 cfs @ 12.44 hrs HW=47.93' (Free Discharge) 2=Sharp-Crested Rectangular Weir (Weir Controls 0.32 cfs @ 0.70 fps) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 17HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 2P: Existing LB's Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)4 3 2 1 0 Inflow Area=0.704 ac Peak Elev=47.93' Storage=4,092 cf 4.04 cfs 1.04 cfs 0.64 cfs 0.40 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 18HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Area = 0.332 ac, 96.99% Impervious, Inflow Depth > 6.75" for 100-Year event Inflow = 2.45 cfs @ 12.07 hrs, Volume= 0.187 af Outflow = 0.40 cfs @ 12.53 hrs, Volume= 0.187 af, Atten= 83%, Lag= 27.3 min Discarded = 0.40 cfs @ 12.53 hrs, Volume= 0.187 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 45.92' @ 12.53 hrs Surf.Area= 1,663 sf Storage= 2,693 cf Plug-Flow detention time= 59.4 min calculated for 0.187 af (100% of inflow) Center-of-Mass det. time= 59.3 min ( 823.5 - 764.2 ) Volume Invert Avail.Storage Storage Description #1 44.00' 4,299 cf Custom Stage Data (Conic) Listed below (Recalc) x 2 #2A 42.07' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #3A 42.57' 1,088 cf Cultec R-330XLHD x 20 Inside #2 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 6,088 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 84 0 0 84 45.00 233 152 152 239 46.00 451 336 488 467 47.00 1,459 907 1,395 1,480 47.35 2,936 754 2,150 2,958 Device Routing Invert Outlet Devices #1 Discarded 42.07'8.270 in/hr Exfiltration over Wetted area from 42.06' - 99.61' Excluded Wetted area = 0 sf #2 Primary 47.02'10.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.40 cfs @ 12.53 hrs HW=45.92' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.40 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=42.07' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 19HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 1P: Cultec 330 Infiltration Chamber with Forebays Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)2 1 0 Inflow Area=0.332 ac Peak Elev=45.92' Storage=2,693 cf 2.45 cfs 0.40 cfs0.40 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 20HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing LB's Inflow Area = 0.704 ac, 78.55% Impervious, Inflow Depth > 5.61" for 100-Year event Inflow = 4.61 cfs @ 12.07 hrs, Volume= 0.329 af Outflow = 1.79 cfs @ 12.30 hrs, Volume= 0.329 af, Atten= 61%, Lag= 13.3 min Discarded = 0.64 cfs @ 12.17 hrs, Volume= 0.304 af Primary = 1.15 cfs @ 12.30 hrs, Volume= 0.025 af Routing by Stor-Ind method, Time Span= 5.00-40.01 hrs, dt= 0.03 hrs Peak Elev= 47.98' @ 12.30 hrs Surf.Area= 3,998 sf Storage= 4,236 cf Plug-Flow detention time= 50.8 min calculated for 0.329 af (100% of inflow) Center-of-Mass det. time= 50.7 min ( 843.2 - 792.5 ) Volume Invert Avail.Storage Storage Description #1 38.50' 2,650 cf 14.00'W x 14.00'L x 6.50'H Prismatoid x 6 7,644 cf Overall - 1,018 cf Embedded = 6,626 cf x 40.0% Voids #2 39.00' 1,018 cf 6.00'D x 6.00'H Vertical Cone/Cylinder x 6 Inside #1 #3 47.40' 623 cf Custom Stage Data (Conic) Listed below (Recalc) 4,291 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 47.40 4 0 0 4 48.00 3,000 623 623 3,001 Device Routing Invert Outlet Devices #1 Discarded 38.50'8.270 in/hr Exfiltration over Wetted area from 38.40' - 45.00' Excluded Wetted area = 0 sf #2 Primary 47.88'10.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) 0.5' Crest Height Discarded OutFlow Max=0.64 cfs @ 12.17 hrs HW=47.82' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.64 cfs) Primary OutFlow Max=1.07 cfs @ 12.30 hrs HW=47.98' (Free Discharge) 2=Sharp-Crested Rectangular Weir (Weir Controls 1.07 cfs @ 1.06 fps) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 PRE-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 21HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond 2P: Existing LB's Inflow Outflow Discarded Primary Hydrograph Time (hours) 4038363432302826242220181614121086Flow (cfs)5 4 3 2 1 0 Inflow Area=0.704 ac Peak Elev=47.98' Storage=4,236 cf 4.61 cfs 1.79 cfs 0.64 cfs 1.15 cfs Forebay 3 Orifice Check Forebay 1 Orifice Check Forebay 2 Orifice Check 1 Pavement to Exist Forebay 3 1OC Pavement to Exist Forebay 3 2 Site Areas to Forebay 1 2 OC Site Areas to Forebay 1 3 Site Areas to Forebay 2 3OC Site Areas to Forebay 2 3OC Roof 1/4 ROOF - Northeast 4 Area to north 5 Rear Yard Areas 5OC Rear Yard Areas 6 Front Areas to Roadway OC ROOF 1/2 ROOF - West OCR 1/4 ROOF - SE ROOF 1/4 ROOF - SE ROOF2 1/2 ROOF - West ROOF3 1/4 ROOF - Northeast SP1 Study Point 1 SP3 Study Point 3 SP4 FB1 Forebay 1 w Beehive and Cultec 330s FB2 Forebay 2 w Beehive and Cultec 330s FB3 Existing Forebay 3 w Beehive and Existing Cultecs OC1 Forebay 1 Orifice Check OC2 Forebay 2 Orifice Check OC3 Ex. Forebay 3 Orifice Check Routing Diagram for 2021-036 POST-DEVT Prepared by {enter your company name here}, Printed 10/6/2022 HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Subcat Reach Pond Link 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 2HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 2.10" for 2-Year event Inflow = 1.24 cfs @ 12.08 hrs, Volume= 0.089 af Outflow = 0.24 cfs @ 12.52 hrs, Volume= 0.089 af, Atten= 81%, Lag= 26.5 min Discarded = 0.24 cfs @ 12.52 hrs, Volume= 0.089 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 43.86' @ 12.52 hrs Surf.Area= 972 sf Storage= 1,111 cf Plug-Flow detention time= 35.5 min calculated for 0.089 af (100% of inflow) Center-of-Mass det. time= 35.5 min ( 840.7 - 805.2 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) #3A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 8,230 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 802 sf #3 Primary 46.50'10.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 3HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.24 cfs @ 12.52 hrs HW=43.86' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.23 cfs) 2=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.510 ac Peak Elev=43.86' Storage=1,111 cf 1.24 cfs 0.24 cfs0.24 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 4HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 1.07" for 2-Year event Inflow = 0.59 cfs @ 12.08 hrs, Volume= 0.047 af Outflow = 0.12 cfs @ 12.55 hrs, Volume= 0.047 af, Atten= 79%, Lag= 28.0 min Discarded = 0.12 cfs @ 12.55 hrs, Volume= 0.047 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 43.36' @ 12.55 hrs Surf.Area= 504 sf Storage= 472 cf Plug-Flow detention time= 24.6 min calculated for 0.047 af (100% of inflow) Center-of-Mass det. time= 24.5 min ( 864.3 - 839.8 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 450 cf 16.00'W x 31.50'L x 3.54'H Field A 1,785 cf Overall - 659 cf Embedded = 1,126 cf x 40.0% Voids #2A 42.44' 659 cf Cultec R-330XLHD x 12 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows #3 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) 4,904 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 504 sf #3 Primary 45.85'5.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 5HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.12 cfs @ 12.55 hrs HW=43.36' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.12 cfs) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.525 ac Peak Elev=43.36' Storage=472 cf 0.59 cfs 0.12 cfs0.12 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 6HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 1.33" for 2-Year event Inflow = 0.30 cfs @ 12.08 hrs, Volume= 0.023 af Outflow = 0.15 cfs @ 12.00 hrs, Volume= 0.023 af, Atten= 49%, Lag= 0.0 min Discarded = 0.15 cfs @ 12.00 hrs, Volume= 0.023 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 42.19' @ 12.21 hrs Surf.Area= 802 sf Storage= 81 cf Plug-Flow detention time= 3.2 min calculated for 0.023 af (100% of inflow) Center-of-Mass det. time= 3.1 min ( 797.0 - 794.0 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows #3 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) 2,929 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Surface area from 41.93' - 45.48' Excluded Surface area = 0 sf #2 Discarded 43.90'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 1,035 sf #3 Primary 47.02'23.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 7HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.15 cfs @ 12.00 hrs HW=42.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=42.19' Storage=81 cf 0.30 cfs 0.15 cfs0.15 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 8HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC1: Forebay 1 Orifice Check Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 2.10" for 2-Year event Inflow = 1.24 cfs @ 12.08 hrs, Volume= 0.089 af Outflow = 0.30 cfs @ 12.47 hrs, Volume= 0.089 af, Atten= 76%, Lag= 23.9 min Discarded = 0.09 cfs @ 12.47 hrs, Volume= 0.083 af Primary = 0.21 cfs @ 12.47 hrs, Volume= 0.006 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.03' @ 12.47 hrs Surf.Area= 1,608 sf Storage= 1,734 cf Plug-Flow detention time= 243.0 min calculated for 0.089 af (100% of inflow) Center-of-Mass det. time= 242.8 min ( 1,048.0 - 805.2 ) Volume Invert Avail.Storage Storage Description #1 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 0 sf #2 Device 5 46.00'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.25'1.5" x 2.0" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.42'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.09 cfs @ 12.47 hrs HW=46.03' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.09 cfs) Primary OutFlow Max=0.20 cfs @ 12.47 hrs HW=46.03' (Free Discharge) 5=Culvert (Passes 0.20 cfs of 6.41 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.20 cfs @ 0.61 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 9HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC1: Forebay 1 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.510 ac Peak Elev=46.03' Storage=1,734 cf 1.24 cfs 0.30 cfs 0.09 cfs 0.21 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 10HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC2: Forebay 2 Orifice Check Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 1.07" for 2-Year event Inflow = 0.59 cfs @ 12.08 hrs, Volume= 0.047 af Outflow = 0.11 cfs @ 12.60 hrs, Volume= 0.047 af, Atten= 82%, Lag= 30.9 min Discarded = 0.05 cfs @ 12.60 hrs, Volume= 0.044 af Primary = 0.06 cfs @ 12.60 hrs, Volume= 0.003 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.36' @ 12.60 hrs Surf.Area= 852 sf Storage= 765 cf Plug-Flow detention time= 190.8 min calculated for 0.047 af (100% of inflow) Center-of-Mass det. time= 190.8 min ( 1,030.6 - 839.8 ) Volume Invert Avail.Storage Storage Description #1 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 0 sf #2 Device 5 45.35'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 45.60'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 45.77'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.05 cfs @ 12.60 hrs HW=45.36' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.04 cfs @ 12.60 hrs HW=45.36' (Free Discharge) 5=Culvert (Passes 0.04 cfs of 5.61 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.04 cfs @ 0.36 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 11HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC2: Forebay 2 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.525 ac Peak Elev=45.36' Storage=765 cf 0.59 cfs 0.11 cfs 0.05 cfs0.06 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 12HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC3: Ex. Forebay 3 Orifice Check Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 1.33" for 2-Year event Inflow = 0.30 cfs @ 12.08 hrs, Volume= 0.023 af Outflow = 0.03 cfs @ 13.05 hrs, Volume= 0.023 af, Atten= 91%, Lag= 58.3 min Discarded = 0.03 cfs @ 13.05 hrs, Volume= 0.023 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.07' @ 13.05 hrs Surf.Area= 451 sf Storage= 460 cf Plug-Flow detention time= 219.1 min calculated for 0.023 af (100% of inflow) Center-of-Mass det. time= 218.9 min ( 1,012.9 - 794.0 ) Volume Invert Avail.Storage Storage Description #1 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 44.00'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 0 sf #2 Device 5 46.36'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.61'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.78'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.73'12.0" Round Culvert L= 29.0' Ke= 0.500 Inlet / Outlet Invert= 42.73' / 42.44' S= 0.0100 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 13.05 hrs HW=46.07' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=44.00' (Free Discharge) 5=Culvert (Passes 0.00 cfs of 3.30 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 2-Year Rainfall=3.38"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 13HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC3: Ex. Forebay 3 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=46.07' Storage=460 cf 0.30 cfs 0.03 cfs0.03 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 14HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 3.47" for 10-Year event Inflow = 2.05 cfs @ 12.08 hrs, Volume= 0.148 af Outflow = 0.40 cfs @ 12.51 hrs, Volume= 0.148 af, Atten= 81%, Lag= 26.1 min Discarded = 0.40 cfs @ 12.51 hrs, Volume= 0.148 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 44.85' @ 12.51 hrs Surf.Area= 1,509 sf Storage= 2,037 cf Plug-Flow detention time= 49.1 min calculated for 0.148 af (100% of inflow) Center-of-Mass det. time= 49.0 min ( 845.0 - 796.0 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) #3A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 8,230 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 802 sf #3 Primary 46.50'10.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 15HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.40 cfs @ 12.51 hrs HW=44.85' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.36 cfs) 2=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.510 ac Peak Elev=44.85' Storage=2,037 cf 2.05 cfs 0.40 cfs0.40 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 16HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 2.10" for 10-Year event Inflow = 1.25 cfs @ 12.08 hrs, Volume= 0.092 af Outflow = 0.26 cfs @ 12.53 hrs, Volume= 0.092 af, Atten= 79%, Lag= 26.8 min Discarded = 0.26 cfs @ 12.53 hrs, Volume= 0.092 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 44.60' @ 12.53 hrs Surf.Area= 972 sf Storage= 1,174 cf Plug-Flow detention time= 45.1 min calculated for 0.092 af (100% of inflow) Center-of-Mass det. time= 45.0 min ( 875.3 - 830.3 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 450 cf 16.00'W x 31.50'L x 3.54'H Field A 1,785 cf Overall - 659 cf Embedded = 1,126 cf x 40.0% Voids #2A 42.44' 659 cf Cultec R-330XLHD x 12 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows #3 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) 4,904 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 504 sf #3 Primary 45.85'5.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 17HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.26 cfs @ 12.53 hrs HW=44.60' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.24 cfs) 2=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.525 ac Peak Elev=44.60' Storage=1,174 cf 1.25 cfs 0.26 cfs0.26 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 18HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 2.26" for 10-Year event Inflow = 0.49 cfs @ 12.08 hrs, Volume= 0.039 af Outflow = 0.15 cfs @ 11.88 hrs, Volume= 0.039 af, Atten= 69%, Lag= 0.0 min Discarded = 0.15 cfs @ 11.88 hrs, Volume= 0.039 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 42.59' @ 12.41 hrs Surf.Area= 802 sf Storage= 260 cf Plug-Flow detention time= 8.5 min calculated for 0.039 af (100% of inflow) Center-of-Mass det. time= 8.3 min ( 805.7 - 797.3 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows #3 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) 2,929 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Surface area from 41.93' - 45.48' Excluded Surface area = 0 sf #2 Discarded 43.90'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 1,035 sf #3 Primary 47.02'23.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 19HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.15 cfs @ 11.88 hrs HW=42.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=42.59' Storage=260 cf 0.49 cfs 0.15 cfs0.15 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 20HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC1: Forebay 1 Orifice Check Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 3.47" for 10-Year event Inflow = 2.05 cfs @ 12.08 hrs, Volume= 0.148 af Outflow = 0.95 cfs @ 12.24 hrs, Volume= 0.148 af, Atten= 53%, Lag= 9.6 min Discarded = 0.15 cfs @ 12.24 hrs, Volume= 0.101 af Primary = 0.80 cfs @ 12.24 hrs, Volume= 0.046 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.25' @ 12.24 hrs Surf.Area= 2,745 sf Storage= 2,192 cf Plug-Flow detention time= 184.6 min calculated for 0.148 af (100% of inflow) Center-of-Mass det. time= 184.4 min ( 980.4 - 796.0 ) Volume Invert Avail.Storage Storage Description #1 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 0 sf #2 Device 5 46.00'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.25'1.5" x 2.0" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.42'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.15 cfs @ 12.24 hrs HW=46.25' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) Primary OutFlow Max=0.80 cfs @ 12.24 hrs HW=46.25' (Free Discharge) 5=Culvert (Passes 0.80 cfs of 6.64 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.80 cfs @ 2.40 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 21HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC1: Forebay 1 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.510 ac Peak Elev=46.25' Storage=2,192 cf 2.05 cfs 0.95 cfs 0.15 cfs 0.80 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 22HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC2: Forebay 2 Orifice Check Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 2.10" for 10-Year event Inflow = 1.25 cfs @ 12.08 hrs, Volume= 0.092 af Outflow = 0.79 cfs @ 12.18 hrs, Volume= 0.092 af, Atten= 37%, Lag= 5.9 min Discarded = 0.05 cfs @ 12.18 hrs, Volume= 0.056 af Primary = 0.74 cfs @ 12.18 hrs, Volume= 0.036 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.56' @ 12.18 hrs Surf.Area= 951 sf Storage= 944 cf Plug-Flow detention time= 132.1 min calculated for 0.092 af (100% of inflow) Center-of-Mass det. time= 131.9 min ( 962.1 - 830.3 ) Volume Invert Avail.Storage Storage Description #1 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 0 sf #2 Device 5 45.35'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 45.60'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 45.77'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.05 cfs @ 12.18 hrs HW=45.56' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.73 cfs @ 12.18 hrs HW=45.56' (Free Discharge) 5=Culvert (Passes 0.73 cfs of 5.85 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.73 cfs @ 2.19 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 23HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC2: Forebay 2 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.525 ac Peak Elev=45.56' Storage=944 cf 1.25 cfs 0.79 cfs 0.05 cfs 0.74 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 24HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC3: Ex. Forebay 3 Orifice Check Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 2.26" for 10-Year event Inflow = 0.49 cfs @ 12.08 hrs, Volume= 0.039 af Outflow = 0.24 cfs @ 12.26 hrs, Volume= 0.039 af, Atten= 51%, Lag= 11.0 min Discarded = 0.03 cfs @ 12.24 hrs, Volume= 0.033 af Primary = 0.21 cfs @ 12.26 hrs, Volume= 0.006 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.39' @ 12.24 hrs Surf.Area= 575 sf Storage= 626 cf Plug-Flow detention time= 215.1 min calculated for 0.039 af (100% of inflow) Center-of-Mass det. time= 214.8 min ( 1,012.1 - 797.3 ) Volume Invert Avail.Storage Storage Description #1 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 44.00'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 0 sf #2 Device 5 46.36'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.61'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.78'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.73'12.0" Round Culvert L= 29.0' Ke= 0.500 Inlet / Outlet Invert= 42.73' / 42.44' S= 0.0100 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 12.24 hrs HW=46.39' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.19 cfs @ 12.26 hrs HW=46.39' (Free Discharge) 5=Culvert (Passes 0.19 cfs of 6.73 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.19 cfs @ 0.60 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 10-Year Rainfall=4.92"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 25HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC3: Ex. Forebay 3 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=46.39' Storage=626 cf 0.49 cfs 0.24 cfs 0.03 cfs 0.21 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 26HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 4.36" for 25-Year event Inflow = 2.56 cfs @ 12.07 hrs, Volume= 0.185 af Outflow = 0.49 cfs @ 12.51 hrs, Volume= 0.185 af, Atten= 81%, Lag= 26.2 min Discarded = 0.49 cfs @ 12.51 hrs, Volume= 0.185 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.37' @ 12.51 hrs Surf.Area= 1,829 sf Storage= 2,656 cf Plug-Flow detention time= 54.4 min calculated for 0.185 af (100% of inflow) Center-of-Mass det. time= 54.4 min ( 845.9 - 791.6 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) #3A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 8,230 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 802 sf #3 Primary 46.50'10.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 27HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.49 cfs @ 12.51 hrs HW=45.37' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.43 cfs) 2=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.510 ac Peak Elev=45.37' Storage=2,656 cf 2.56 cfs 0.49 cfs0.49 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 28HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 2.82" for 25-Year event Inflow = 1.71 cfs @ 12.08 hrs, Volume= 0.123 af Outflow = 0.35 cfs @ 12.52 hrs, Volume= 0.123 af, Atten= 80%, Lag= 26.7 min Discarded = 0.35 cfs @ 12.52 hrs, Volume= 0.123 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.19' @ 12.52 hrs Surf.Area= 1,275 sf Storage= 1,679 cf Plug-Flow detention time= 51.7 min calculated for 0.123 af (100% of inflow) Center-of-Mass det. time= 51.6 min ( 876.7 - 825.1 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 450 cf 16.00'W x 31.50'L x 3.54'H Field A 1,785 cf Overall - 659 cf Embedded = 1,126 cf x 40.0% Voids #2A 42.44' 659 cf Cultec R-330XLHD x 12 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows #3 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) 4,904 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 504 sf #3 Primary 45.85'5.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 29HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.35 cfs @ 12.52 hrs HW=45.19' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.30 cfs) 2=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.525 ac Peak Elev=45.19' Storage=1,679 cf 1.71 cfs 0.35 cfs0.35 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 30HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 2.90" for 25-Year event Inflow = 0.64 cfs @ 12.08 hrs, Volume= 0.050 af Outflow = 0.15 cfs @ 11.80 hrs, Volume= 0.050 af, Atten= 76%, Lag= 0.0 min Discarded = 0.15 cfs @ 11.80 hrs, Volume= 0.050 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 42.86' @ 12.48 hrs Surf.Area= 802 sf Storage= 436 cf Plug-Flow detention time= 14.7 min calculated for 0.050 af (100% of inflow) Center-of-Mass det. time= 14.6 min ( 812.2 - 797.6 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows #3 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) 2,929 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Surface area from 41.93' - 45.48' Excluded Surface area = 0 sf #2 Discarded 43.90'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 1,035 sf #3 Primary 47.02'23.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 31HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.15 cfs @ 11.80 hrs HW=42.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=42.86' Storage=436 cf 0.64 cfs 0.15 cfs0.15 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 32HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC1: Forebay 1 Orifice Check Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 4.36" for 25-Year event Inflow = 2.56 cfs @ 12.07 hrs, Volume= 0.185 af Outflow = 1.46 cfs @ 12.18 hrs, Volume= 0.185 af, Atten= 43%, Lag= 6.6 min Discarded = 0.19 cfs @ 12.18 hrs, Volume= 0.112 af Primary = 1.27 cfs @ 12.18 hrs, Volume= 0.074 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.35' @ 12.18 hrs Surf.Area= 3,401 sf Storage= 2,507 cf Plug-Flow detention time= 162.8 min calculated for 0.185 af (100% of inflow) Center-of-Mass det. time= 163.2 min ( 954.7 - 791.6 ) Volume Invert Avail.Storage Storage Description #1 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 0 sf #2 Device 5 46.00'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.25'1.5" x 2.0" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.42'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.19 cfs @ 12.18 hrs HW=46.35' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=1.26 cfs @ 12.18 hrs HW=46.35' (Free Discharge) 5=Culvert (Passes 1.26 cfs of 6.75 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.95 cfs @ 2.85 fps) 3=Orifice/Grate (Orifice Controls 0.32 cfs @ 1.52 fps) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 33HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC1: Forebay 1 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.510 ac Peak Elev=46.35' Storage=2,507 cf 2.56 cfs 1.46 cfs 0.19 cfs 1.27 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 34HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC2: Forebay 2 Orifice Check Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 2.82" for 25-Year event Inflow = 1.71 cfs @ 12.08 hrs, Volume= 0.123 af Outflow = 1.29 cfs @ 12.15 hrs, Volume= 0.123 af, Atten= 25%, Lag= 4.1 min Discarded = 0.06 cfs @ 12.15 hrs, Volume= 0.062 af Primary = 1.23 cfs @ 12.15 hrs, Volume= 0.062 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.72' @ 12.15 hrs Surf.Area= 1,034 sf Storage= 1,099 cf Plug-Flow detention time= 111.8 min calculated for 0.123 af (100% of inflow) Center-of-Mass det. time= 111.6 min ( 936.7 - 825.1 ) Volume Invert Avail.Storage Storage Description #1 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 0 sf #2 Device 5 45.35'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 45.60'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 45.77'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 12.15 hrs HW=45.71' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.22 cfs @ 12.15 hrs HW=45.71' (Free Discharge) 5=Culvert (Passes 1.22 cfs of 6.04 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.97 cfs @ 2.90 fps) 3=Orifice/Grate (Orifice Controls 0.25 cfs @ 1.62 fps) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 35HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC2: Forebay 2 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.525 ac Peak Elev=45.72' Storage=1,099 cf 1.71 cfs 1.29 cfs 0.06 cfs 1.23 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 36HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC3: Ex. Forebay 3 Orifice Check Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 2.90" for 25-Year event Inflow = 0.64 cfs @ 12.08 hrs, Volume= 0.050 af Outflow = 0.55 cfs @ 12.14 hrs, Volume= 0.050 af, Atten= 14%, Lag= 3.7 min Discarded = 0.03 cfs @ 12.14 hrs, Volume= 0.037 af Primary = 0.52 cfs @ 12.14 hrs, Volume= 0.013 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.45' @ 12.14 hrs Surf.Area= 599 sf Storage= 661 cf Plug-Flow detention time= 188.5 min calculated for 0.050 af (100% of inflow) Center-of-Mass det. time= 188.6 min ( 986.2 - 797.6 ) Volume Invert Avail.Storage Storage Description #1 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 44.00'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 0 sf #2 Device 5 46.36'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.61'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.78'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.73'12.0" Round Culvert L= 29.0' Ke= 0.500 Inlet / Outlet Invert= 42.73' / 42.44' S= 0.0100 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.03 cfs @ 12.14 hrs HW=46.44' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.46 cfs @ 12.14 hrs HW=46.44' (Free Discharge) 5=Culvert (Passes 0.46 cfs of 6.78 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.46 cfs @ 1.39 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 25-Year Rainfall=5.88"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 37HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC3: Ex. Forebay 3 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=46.45' Storage=661 cf 0.64 cfs 0.55 cfs 0.03 cfs 0.52 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 38HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 5.05" for 50 Year event Inflow = 2.95 cfs @ 12.07 hrs, Volume= 0.214 af Outflow = 0.52 cfs @ 12.53 hrs, Volume= 0.214 af, Atten= 82%, Lag= 27.1 min Discarded = 0.52 cfs @ 12.53 hrs, Volume= 0.214 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.79' @ 12.53 hrs Surf.Area= 2,101 sf Storage= 3,176 cf Plug-Flow detention time= 59.0 min calculated for 0.214 af (100% of inflow) Center-of-Mass det. time= 58.9 min ( 847.6 - 788.7 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) #3A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 8,230 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 802 sf #3 Primary 46.50'10.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 39HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.52 cfs @ 12.53 hrs HW=45.79' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.45 cfs) 2=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)3 2 1 0 Inflow Area=0.510 ac Peak Elev=45.79' Storage=3,176 cf 2.95 cfs 0.52 cfs0.52 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 40HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 3.39" for 50 Year event Inflow = 2.07 cfs @ 12.08 hrs, Volume= 0.148 af Outflow = 0.39 cfs @ 12.54 hrs, Volume= 0.148 af, Atten= 81%, Lag= 27.4 min Discarded = 0.39 cfs @ 12.54 hrs, Volume= 0.148 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.63' @ 12.54 hrs Surf.Area= 1,489 sf Storage= 2,116 cf Plug-Flow detention time= 56.7 min calculated for 0.148 af (100% of inflow) Center-of-Mass det. time= 56.6 min ( 878.1 - 821.6 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 450 cf 16.00'W x 31.50'L x 3.54'H Field A 1,785 cf Overall - 659 cf Embedded = 1,126 cf x 40.0% Voids #2A 42.44' 659 cf Cultec R-330XLHD x 12 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows #3 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) 4,904 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 504 sf #3 Primary 45.85'5.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 41HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.39 cfs @ 12.54 hrs HW=45.62' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.34 cfs) 2=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.525 ac Peak Elev=45.63' Storage=2,116 cf 2.07 cfs 0.39 cfs0.39 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 42HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 3.42" for 50 Year event Inflow = 0.77 cfs @ 12.08 hrs, Volume= 0.059 af Outflow = 0.15 cfs @ 11.76 hrs, Volume= 0.059 af, Atten= 80%, Lag= 0.0 min Discarded = 0.15 cfs @ 11.76 hrs, Volume= 0.059 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 43.09' @ 12.52 hrs Surf.Area= 802 sf Storage= 592 cf Plug-Flow detention time= 21.2 min calculated for 0.059 af (100% of inflow) Center-of-Mass det. time= 21.0 min ( 818.4 - 797.4 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows #3 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) 2,929 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Surface area from 41.93' - 45.48' Excluded Surface area = 0 sf #2 Discarded 43.90'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 1,035 sf #3 Primary 47.02'23.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 43HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.15 cfs @ 11.76 hrs HW=42.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=43.09' Storage=592 cf 0.77 cfs 0.15 cfs0.15 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 44HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC1: Forebay 1 Orifice Check Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 5.05" for 50 Year event Inflow = 2.95 cfs @ 12.07 hrs, Volume= 0.214 af Outflow = 1.66 cfs @ 12.19 hrs, Volume= 0.214 af, Atten= 44%, Lag= 6.7 min Discarded = 0.21 cfs @ 12.16 hrs, Volume= 0.119 af Primary = 1.45 cfs @ 12.19 hrs, Volume= 0.095 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.42' @ 12.19 hrs Surf.Area= 3,868 sf Storage= 2,751 cf Plug-Flow detention time= 151.0 min calculated for 0.214 af (100% of inflow) Center-of-Mass det. time= 151.4 min ( 940.1 - 788.7 ) Volume Invert Avail.Storage Storage Description #1 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 0 sf #2 Device 5 46.00'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.25'1.5" x 2.0" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.42'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.21 cfs @ 12.16 hrs HW=46.42' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.21 cfs) Primary OutFlow Max=1.44 cfs @ 12.19 hrs HW=46.42' (Free Discharge) 5=Culvert (Passes 1.44 cfs of 6.82 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.04 cfs @ 3.11 fps) 3=Orifice/Grate (Orifice Controls 0.41 cfs @ 1.96 fps) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 45HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC1: Forebay 1 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)3 2 1 0 Inflow Area=0.510 ac Peak Elev=46.42' Storage=2,751 cf 2.95 cfs 1.66 cfs 0.21 cfs 1.45 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 46HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC2: Forebay 2 Orifice Check Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 3.39" for 50 Year event Inflow = 2.07 cfs @ 12.08 hrs, Volume= 0.148 af Outflow = 1.60 cfs @ 12.14 hrs, Volume= 0.148 af, Atten= 23%, Lag= 3.8 min Discarded = 0.06 cfs @ 12.12 hrs, Volume= 0.065 af Primary = 1.54 cfs @ 12.14 hrs, Volume= 0.083 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.82' @ 12.14 hrs Surf.Area= 1,088 sf Storage= 1,205 cf Plug-Flow detention time= 100.0 min calculated for 0.148 af (100% of inflow) Center-of-Mass det. time= 100.4 min ( 921.9 - 821.6 ) Volume Invert Avail.Storage Storage Description #1 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 0 sf #2 Device 5 45.35'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 45.60'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 45.77'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 12.12 hrs HW=45.81' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.53 cfs @ 12.14 hrs HW=45.81' (Free Discharge) 5=Culvert (Passes 1.53 cfs of 6.16 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.09 cfs @ 3.28 fps) 3=Orifice/Grate (Orifice Controls 0.35 cfs @ 2.22 fps) 4=Orifice/Grate (Weir Controls 0.09 cfs @ 0.68 fps) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 47HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC2: Forebay 2 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.525 ac Peak Elev=45.82' Storage=1,205 cf 2.07 cfs 1.60 cfs 0.06 cfs 1.54 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 48HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC3: Ex. Forebay 3 Orifice Check Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 3.42" for 50 Year event Inflow = 0.77 cfs @ 12.08 hrs, Volume= 0.059 af Outflow = 0.63 cfs @ 12.13 hrs, Volume= 0.059 af, Atten= 17%, Lag= 3.2 min Discarded = 0.04 cfs @ 12.13 hrs, Volume= 0.039 af Primary = 0.60 cfs @ 12.13 hrs, Volume= 0.020 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.50' @ 12.13 hrs Surf.Area= 618 sf Storage= 689 cf Plug-Flow detention time= 172.2 min calculated for 0.059 af (100% of inflow) Center-of-Mass det. time= 172.4 min ( 969.8 - 797.4 ) Volume Invert Avail.Storage Storage Description #1 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 44.00'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 0 sf #2 Device 5 46.36'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.61'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.78'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.73'12.0" Round Culvert L= 29.0' Ke= 0.500 Inlet / Outlet Invert= 42.73' / 42.44' S= 0.0100 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.04 cfs @ 12.13 hrs HW=46.50' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.59 cfs @ 12.13 hrs HW=46.50' (Free Discharge) 5=Culvert (Passes 0.59 cfs of 6.83 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.59 cfs @ 1.78 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 50 Year Rainfall=6.61"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 49HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC3: Ex. Forebay 3 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)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=0.208 ac Peak Elev=46.50' Storage=689 cf 0.77 cfs 0.63 cfs 0.04 cfs 0.60 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 50HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 5.76" for 100-Year event Inflow = 3.35 cfs @ 12.07 hrs, Volume= 0.245 af Outflow = 0.57 cfs @ 12.53 hrs, Volume= 0.245 af, Atten= 83%, Lag= 27.4 min Discarded = 0.57 cfs @ 12.53 hrs, Volume= 0.245 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.16' @ 12.53 hrs Surf.Area= 3,025 sf Storage= 3,756 cf Plug-Flow detention time= 64.6 min calculated for 0.245 af (100% of inflow) Center-of-Mass det. time= 64.5 min ( 850.6 - 786.1 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) #3A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows 8,230 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 802 sf #3 Primary 46.50'10.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 51HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.57 cfs @ 12.53 hrs HW=46.16' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.45 cfs) 2=Exfiltration (Exfiltration Controls 0.12 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB1: Forebay 1 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)3 2 1 0 Inflow Area=0.510 ac Peak Elev=46.16' Storage=3,756 cf 3.35 cfs 0.57 cfs0.57 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 52HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 4.01" for 100-Year event Inflow = 2.47 cfs @ 12.08 hrs, Volume= 0.176 af Outflow = 0.76 cfs @ 12.41 hrs, Volume= 0.176 af, Atten= 69%, Lag= 20.2 min Discarded = 0.40 cfs @ 12.28 hrs, Volume= 0.169 af Primary = 0.37 cfs @ 12.41 hrs, Volume= 0.006 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.95' @ 12.41 hrs Surf.Area= 1,664 sf Storage= 2,459 cf Plug-Flow detention time= 58.9 min calculated for 0.176 af (100% of inflow) Center-of-Mass det. time= 58.8 min ( 877.1 - 818.3 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 450 cf 16.00'W x 31.50'L x 3.54'H Field A 1,785 cf Overall - 659 cf Embedded = 1,126 cf x 40.0% Voids #2A 42.44' 659 cf Cultec R-330XLHD x 12 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows #3 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) 4,904 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Wetted area from 41.93' - 45.48' Excluded Wetted area = 0 sf #2 Discarded 43.40'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 504 sf #3 Primary 45.85'5.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 53HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.40 cfs @ 12.28 hrs HW=45.82' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.34 cfs) 2=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.35 cfs @ 12.41 hrs HW=45.94' (Free Discharge) 3=Broad-Crested Rectangular Weir (Weir Controls 0.35 cfs @ 0.75 fps) Pond FB2: Forebay 2 w Beehive and Cultec 330s Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.525 ac Peak Elev=45.95' Storage=2,459 cf 2.47 cfs 0.76 cfs 0.40 cfs0.37 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 54HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 3.97" for 100-Year event Inflow = 0.90 cfs @ 12.08 hrs, Volume= 0.069 af Outflow = 0.15 cfs @ 11.72 hrs, Volume= 0.069 af, Atten= 83%, Lag= 0.0 min Discarded = 0.15 cfs @ 11.72 hrs, Volume= 0.069 af Primary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 43.37' @ 12.55 hrs Surf.Area= 802 sf Storage= 769 cf Plug-Flow detention time= 29.4 min calculated for 0.069 af (100% of inflow) Center-of-Mass det. time= 29.3 min ( 826.3 - 797.0 ) Volume Invert Avail.Storage Storage Description #1A 41.94' 701 cf 20.83'W x 38.50'L x 3.54'H Field A 2,841 cf Overall - 1,088 cf Embedded = 1,753 cf x 40.0% Voids #2A 42.44' 1,088 cf Cultec R-330XLHD x 20 Inside #1 Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 4 rows #3 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) 2,929 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 41.94'8.270 in/hr Exfiltration over Surface area from 41.93' - 45.48' Excluded Surface area = 0 sf #2 Discarded 43.90'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 1,035 sf #3 Primary 47.02'23.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 55HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.15 cfs @ 11.72 hrs HW=41.99' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.15 cfs) 2=Exfiltration ( Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 5.00 hrs HW=41.94' (Free Discharge) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond FB3: Existing Forebay 3 w Beehive and Existing Cultecs Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.208 ac Peak Elev=43.37' Storage=769 cf 0.90 cfs 0.15 cfs0.15 cfs 0.00 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 56HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC1: Forebay 1 Orifice Check Inflow Area = 0.510 ac, 81.57% Impervious, Inflow Depth > 5.76" for 100-Year event Inflow = 3.35 cfs @ 12.07 hrs, Volume= 0.245 af Outflow = 1.90 cfs @ 12.18 hrs, Volume= 0.245 af, Atten= 43%, Lag= 6.6 min Discarded = 0.21 cfs @ 12.12 hrs, Volume= 0.126 af Primary = 1.69 cfs @ 12.18 hrs, Volume= 0.119 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.48' @ 12.18 hrs Surf.Area= 4,302 sf Storage= 2,991 cf Plug-Flow detention time= 141.7 min calculated for 0.245 af (100% of inflow) Center-of-Mass det. time= 141.5 min ( 927.6 - 786.1 ) Volume Invert Avail.Storage Storage Description #1 43.50' 6,441 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 41 0 0 41 44.00 244 64 64 245 45.00 812 500 565 818 46.00 1,451 1,116 1,681 1,468 47.00 9,180 4,760 6,441 9,201 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 46.40' Excluded Surface area = 0 sf #2 Device 5 46.00'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.25'1.5" x 2.0" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.42'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.21 cfs @ 12.12 hrs HW=46.45' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.21 cfs) Primary OutFlow Max=1.69 cfs @ 12.18 hrs HW=46.48' (Free Discharge) 5=Culvert (Passes 1.69 cfs of 6.89 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.11 cfs @ 3.32 fps) 3=Orifice/Grate (Orifice Controls 0.48 cfs @ 2.28 fps) 4=Orifice/Grate (Orifice Controls 0.11 cfs @ 1.13 fps) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 57HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC1: Forebay 1 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)3 2 1 0 Inflow Area=0.510 ac Peak Elev=46.48' Storage=2,991 cf 3.35 cfs 1.90 cfs 0.21 cfs 1.69 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 58HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC2: Forebay 2 Orifice Check Inflow Area = 0.525 ac, 55.05% Impervious, Inflow Depth > 4.01" for 100-Year event Inflow = 2.47 cfs @ 12.08 hrs, Volume= 0.176 af Outflow = 1.87 cfs @ 12.14 hrs, Volume= 0.176 af, Atten= 24%, Lag= 4.0 min Discarded = 0.06 cfs @ 12.08 hrs, Volume= 0.069 af Primary = 1.81 cfs @ 12.14 hrs, Volume= 0.106 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 45.92' @ 12.14 hrs Surf.Area= 1,144 sf Storage= 1,318 cf Plug-Flow detention time= 91.3 min calculated for 0.176 af (100% of inflow) Center-of-Mass det. time= 91.1 min ( 909.4 - 818.3 ) Volume Invert Avail.Storage Storage Description #1 43.50' 3,795 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 43.50 31 0 0 31 44.00 221 56 56 222 45.00 684 431 487 691 46.00 1,191 926 1,413 1,209 47.00 3,821 2,382 3,795 3,844 Device Routing Invert Outlet Devices #1 Discarded 43.50'2.410 in/hr Exfiltration over Surface area from 43.40' - 45.75' Excluded Surface area = 0 sf #2 Device 5 45.35'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 45.60'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 45.77'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.66'12.0" Round Culvert L= 20.0' Ke= 0.500 Inlet / Outlet Invert= 42.66' / 42.44' S= 0.0110 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.06 cfs @ 12.08 hrs HW=45.84' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.80 cfs @ 12.14 hrs HW=45.91' (Free Discharge) 5=Culvert (Passes 1.80 cfs of 6.27 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.20 cfs @ 3.61 fps) 3=Orifice/Grate (Orifice Controls 0.42 cfs @ 2.69 fps) 4=Orifice/Grate (Orifice Controls 0.17 cfs @ 1.82 fps) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 59HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC2: Forebay 2 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)2 1 0 Inflow Area=0.525 ac Peak Elev=45.92' Storage=1,318 cf 2.47 cfs 1.87 cfs 0.06 cfs 1.81 cfs 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 60HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Summary for Pond OC3: Ex. Forebay 3 Orifice Check Inflow Area = 0.208 ac, 55.77% Impervious, Inflow Depth > 3.97" for 100-Year event Inflow = 0.90 cfs @ 12.08 hrs, Volume= 0.069 af Outflow = 0.74 cfs @ 12.13 hrs, Volume= 0.069 af, Atten= 18%, Lag= 3.2 min Discarded = 0.04 cfs @ 12.13 hrs, Volume= 0.041 af Primary = 0.70 cfs @ 12.13 hrs, Volume= 0.028 af Routing by Stor-Ind method, Time Span= 5.00-40.00 hrs, dt= 0.04 hrs Peak Elev= 46.55' @ 12.13 hrs Surf.Area= 641 sf Storage= 722 cf Plug-Flow detention time= 158.9 min calculated for 0.069 af (100% of inflow) Center-of-Mass det. time= 158.6 min ( 955.6 - 797.0 ) Volume Invert Avail.Storage Storage Description #1 44.00' 1,140 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 44.00 53 0 0 53 45.00 205 121 121 210 46.00 426 309 430 439 47.00 847 625 1,054 869 47.10 875 86 1,140 899 Device Routing Invert Outlet Devices #1 Discarded 44.00'2.410 in/hr Exfiltration over Wetted area from 43.90' - 46.88' Excluded Wetted area = 0 sf #2 Device 5 46.36'1.5" x 2.0" Horiz. Orifice/Grate X 16.00 C= 0.600 Limited to weir flow at low heads #3 Device 5 46.61'1.5" x 1.5" Horiz. Orifice/Grate X 10.00 C= 0.600 Limited to weir flow at low heads #4 Device 5 46.78'1.5" x 1.5" Horiz. Orifice/Grate X 6.00 C= 0.600 Limited to weir flow at low heads #5 Primary 42.73'12.0" Round Culvert L= 29.0' Ke= 0.500 Inlet / Outlet Invert= 42.73' / 42.44' S= 0.0100 '/' Cc= 0.900 n= 0.012, Flow Area= 0.79 sf Discarded OutFlow Max=0.04 cfs @ 12.13 hrs HW=46.55' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.70 cfs @ 12.13 hrs HW=46.55' (Free Discharge) 5=Culvert (Passes 0.70 cfs of 6.89 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.70 cfs @ 2.09 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 212 Mid-Tech Drive, West Yarmouth, MA Type III 24-hr 100-Year Rainfall=7.37"2021-036 POST-DEVT Printed 10/6/2022Prepared by {enter your company name here} Page 61HydroCAD® 10.00-11 s/n 04803 © 2014 HydroCAD Software Solutions LLC Pond OC3: Ex. Forebay 3 Orifice Check Inflow Outflow Discarded Primary Hydrograph Time (hours) 4039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)1 0 Inflow Area=0.208 ac Peak Elev=46.55' Storage=722 cf 0.90 cfs 0.74 cfs 0.04 cfs 0.70 cfs Date: October 6, 2022 Project Site: Proposed Contractor Bays, 212 Mid-Tech Drive, West Yarmouth Stormwater Operations, Maintenance, and Inspections Plan 1. This operations, maintenance, and inspections plan shall be performed by the general contractor during construction operations and by the owner once the facilities are completed and put into operation. Owner of stormwater management system: Turtle Rock, LLC. Persons responsible for operation and maintenance of system: Jeff Bilezikian. Persons responsible for financing maintenance and emergency repairs: Jeff Bilezikian. 2. Personnel associated with the construction of this project shall be informed that the maintenance of siltation controls takes precedence over normal construction activities. Adjacent properties and streets shall be protected from erosion or siltation conditions. 3. A system for stormwater runoff collection and management has been designed using BMP’s (Best Management Practices) as defined by Mass Dept. of Environmental Protection (MDEP) for the 212 Mid-Tech Drive site.(The Project). The collection and conveyance system is comprised of overland flow through curb openings to sediment forebays. These systems collect, treat, attenuate and convey the runoff to the infiltration systems. All the runoff from the building roof area is captured and conveyed directly to the forebays. These basins, along with the Cultec 330 Recharger units, control and infiltrate through the 100 year storm events and assist in removing suspended solids including sediments, oil and grease from the stormwater run-off while allowing for nitrogen uptake through the vegetation. The facilities as sized will retain and infiltration the runoff through the 100-year storm event. To keep the SMS functioning properly and to ensure that the stormwater TSS and other pollutants are reduced, periodic maintenance is required. Turtle Rock, LLC, owner/operator of the Project facility, is responsible for the periodic maintenance requirements of the O&M Plan for the SMS. The following is a guideline of the minimum maintenance schedules and tasks required to keep the SMS functioning properly. Inspection and maintenance, as outlined herein, shall be performed four times within the first year of operation. Thence, inspections and maintenance shall be conducted on a semiannual basis (2 times per year) and after all large storms. An inspection report shall be maintained. 4. Unscheduled Maintenance: The following inspections and maintenance activities should be completed after each rain event in excess of two-and one-half inches (2.5”), or after any significant event accompanied by high winds. General judgment needs to be used. If there appears to be significant debris after a storm event, maintenance personnel should walk the site to inspect for and address the following: a. Inspect the curb opening inlets, riprap areas, and vegetated forebays for debris. Remove any branches, trash or other large debris. b. Inspect roof downspouts, leaders and outfalls to ensure they are not clogged. If roof leaders are clogged they shall be cleaned out by snaking or other acceptable means. c. Inspect the catch basins in the forebays. Remove any branches, trash or other large debris. d. Inspect the Cultec inspection ports for debris. Remove any branches, trash or other large debris. e. Accumulated debris in curb openings, catch basins, forebays, rip rap aprons, and leaching structures shall be removed before it exceeds 12 inches in depth and disposed of properly. f. Broken or damaged gas traps/hoods shall be immediately repaired or replaced to ensure adequate function. 5. General Maintenance: a. A visual inspection shall be made at all access manholes, curb openings, catch basins, forebays, inspection ports, leaching structures, pipes, roof downspouts, gutters, leaders and drainage channels for the entire storm drainage system. If roof leaders are clogged they shall be cleaned out by snaking or other acceptable means b. Maintain the vegetated side slopes and bottom of the vegetated forebays. Areas that consist of grass standing are to be mowed at least once per year to prevent undesirable woody vegetation from taking hold. Remove any grass clippings and trimmings from the SWM areas to prevent them from impeding the flow of stormwater or slowing infiltration rates. c. In the fall remove any accumulated leaves from the curb openings, forebays, and catch basins. Prevent fallen leaves from accumulating over and blocking any inlets. d. In the spring perform a cleanup to remove any accumulated leaves, branches, or debris from the SMS. The forebays, and infiltration systems shall be inspected for cracking, erosion, and accumulated sediment. Sediment removal and repair of the area shall occur as needed. Sediment removal shall be done by either hand or vacuum. Damage to the area must absolutely be avoided. All areas shall be raked out and stabilized after removal of sediment or debris as needed. e. Sediment from catch basin sumps shall be removed when it’s a depth of 24” (this would put sediment to within 24” of the outlet invert on 4 foot sumps). Catch basins should be inspected in the spring and sediment removed by vacuum or clam shell or other appropriate method. Care shall be made to not damage the hood in the catch basin. If it is damaged, it shall be replaced per the original detail within the plans. f. Inspect the Cultec inspection ports for debris. Remove any branches, trash or other large debris. 6. Semi-Annual Maintenance The following inspections and maintenance activities must be completed twice per year (generally April 15, and October 15 or other acceptable quarterly dates): a. Inspect curb openings for debris. Remove any branches, trash or other large debris that could interfere with the proper operation of the outlet of the curb opening. Remove accumulated sediment around the opening. b. Inspect the forebays for debris. Remove any branches, trash or other large debris that could interfere with the proper operation. Remove any accumulated sediment, by the use of hand tools (shovels, rakes, wheelbarrows, etc.) when it exceeds six-inches (6”) but not less than annually. c. Inspect all stone riprap outfalls and overflow areas. The stone acts to stabilize the ground but also dissipate the erosive velocities and energy in the stormwater runoff. Stone berms are intended to slow the stormwater runoff and allow it to permeate through the stone to downstream areas. To keep the stone functioning as intended, it shall be cleaned of sediment and debris. If stone has moved or broken down it shall be replaced and chinked to interlock stones together. Add stone to these areas as needed as the stone settles or is transported to keep these areas stabilized. Any cracking, channeling in soil or erosion shall be repaired immediately. d. Inspect all areas for erosion, cracking, or excessive sediment transport. Repair any erosion or cracking areas immediately. e. Inspect the forebays/infiltration basins for debris. Remove any branches, trash or other large debris. Remove any accumulated sediment, by the use of small mini-track (“Bobcat” or equivalent) equipment if needed or by hand (shovels, rakes, wheelbarrows, etc.) when it reaches a maximum of six-inches (6”) but not less than annually. Vegetation shall be inspected to ensure a reasonable growth and survival rate of at least 75% of the plantings. Dead or dying vegetation shall be replaced in-kind or with equal plantings. 7. All debris or deleterious material shall be removed from drainage structures. Bioswale slopes shall be maintained with a grass stand of at least 3". Grass shall be mowed at least twice a year and clippings shall not be left in basin. Any trees or other woody vegetation growing in embankments or near control structures shall be removed. 8. Good housekeeping measures to reduce sources of sediment, phosphorus, nitrogen, and other contaminants in stormwater runoff shall include: a. No washing of vehicles is allowed on-site inside or outside building. b. Removal of sediment, leaf litter, and other organic debris from impervious surfaces a minimum of twice a year in the spring and fall. c. Removal of sediment and debris from catch basins a minimum of once per year. d. Restrictions on fertilizer applications, including: i. Fertilizer shall not be applied during or immediately prior to heavy rainfall ii. Fertilizer shall not be applied between Nov.12 and the following March 31 iii. Fertilizer shall not be applied, spilled, or deposited on impervious surfaces or in a manner that allows it to enter into storm drains iv. Fertilizer shall not be applied within 100 feet of any surface water or within the Zone I of a public drinking water well. v. Fertilizer containing phosphorus shall not be applied unless a soil test taken no more than three years before the proposed fertilizer application indicated that additional phosphorus is needed for growth of that turf, or unless establishing new turf or reestablishing or repairing turf after substantial damage or land disturbance. vi. A single application fertilizer that contains nitrogen shall not exceed 1 pound of nitrogen per 1000 sf, shall consist of at least 20% slow-release nitrogen (SRN) fertilizer. vii. Grass clippings, leaves, or any other vegetative debris shall not be deposited into or within 50 feet of water bodies, retention and detention areas, drainage ditches, or stormwater drains, or onto impervious surfaces, such as, but not limited to, roadways, and sidewalks, except during scheduled cleanup programs. 9. The following minimum information shall be recorded in a log of each SWM inspection: a. date of inspection b. general condition of the entire system c. corrective actions taken to ensure adequate function and when performed. d. list any repairs, replacements, and disposal (including locations) of any parts or materials. e. a copy of these reports shall be furnished to conservation, department of municipal inspections, and the Comm. of Massachusetts upon request. f. Owner shall allow Conservation and/or department of public works to inspect site bmp’s to determine whether responsible party is implementing the O & M plan. 10. Maintenance of the stormwater management facilities shall be in accordance with the executed operation and maintenance agreement for private stormwater management facilities and shall be the responsibility of the owner and the assignees. 11. The estimated annual operation and maintenance budget for these stormwater O & M measures is $1400 per year. (Estimate does not include repair work if needed.) 12. Owner shall submit an annual certification on November 1 each year, signed by the owner, documenting how non-structural and good-housekeeping practices over the last 12 months have been adhered to this O & M plan, and document the work that has been done over the last 12 months to property operate and maintain the stormwater control measures. Every fifth year, beginning on the fifth year of maintenance, such certification must be prepared by a professional engineer and signed by both the owner and engineer. 13. The owner of the SWM system shall notify Conservation Commission of changes in ownership or assignment of financial responsibility. Inspection Item Inspection Frequency Date Inspected Weather at Time Minimum Maintenance Cleaning or Date of Cleaning Repair Recommendations/of Inspection- Note & Key Items to Check Repair needed Cleaning/ Performed by: Corrective Actionsof Weather Conds.(list Items) RepairSince Last Inspect.Curb OpeningsCatch BasinsVegetated FofrebaysUnderground Infiltration Facilities Roof drains/leadersErosion and StabilizationVegetation - Survival/HealthMowing/trimming of SWM areasStreet/ Parking Lot Sweeping In the Event of a Spill refer to the spill response procedure and contact appropriate agencies. Describe any Corrective action required at this time (attached figures to show location of concern):SMS INSPECTION FORM212 Mid-Tech Drive, West Yarmouth, MA LOCUS