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Home My WebLink AboutSW6220505_Supplement-EZ Form_20230414SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION _ 1 Project Name _ Project Area (ac) _ Coastal Wetland Area ac Utility Improvements to Serve Shabain Reserve - Phase 1 115.32 _ - 2 3 4 Surface Water Area ac 5 Is this ro'ect High or Low Density? High 6 Does this project use an off -site SCM? _ No COMPLIANCE WITH 02H .1003(4.) 7 Width of vegetated setbacks provided (feet) 30 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback, does it meet NCAC 02H.1003 4 c-d ? No 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMS: 11 Infiltration System 1 12 Bioretention Cell 0 13 Wet Pond 3 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting RWH 0 18 1 Green Roof 0 119 Level S reader -Filter Strip (IS-FS 0 20 Disconnected Impervious Surface (DIS) 0 21 Treatment Swale 0 22 Dry Pond 0 23 StormFilter 0 24 Silva Cell 0 25 113ayfilter 0 26 IFilterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 28 I.Name_and T .ale Organization: Street address: Carlo Pardo, PE Bowman North Carolina Ltd. 29 4006 Barrett Drive, Suite 104 30 Cit , State, Zip: Raleigh, NC 27609 31 Phone number(sj: Email: 919-553-6570 32 cpardo@bowman.com Certification Statement: I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here ,`�``�`o��H a R��i''f�� / J v • SEAL _ 051571 = i r %. •• •• ENG I PI�E�•'' r ,gRL o..E. !l l t! I l l l t tSeaf Signature of Designer 4 �a Date DRAINAGE AREAS 1 Is this a hi h density project? Yes 2 If so, number of drainage areas/SCMs 4 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 5 Is all/part of this project subject to previous rule versions? No FORMS LOADED AREA INFORMATION Entire Site 1 2 3 4 4 T e of SCM - Wet Pond Infiltration Basin Wet Pond Wet Pond 5 Total draina a area s ft 5023339 sf 883772 394402 176822 874858 6 Onsite draina a areas ft 883772 394402 176822 874858 7 Offsite draina a area s ft 8 Total BUA in project (sq ft 980497 sf 371638 sf 171155 sf 86745 sf 350959 sf 9permitting) New BUA on subdivided lots (subject to s ft 680000 sf 272000 sf 112000 sf 64000 sf 232000 sf 10permitting) New BUA not on subdivided lots (subject to s 300497 sf 99638 sf 59155 sf 22745 sf 118959 sf 11 10ffsite BUA (sq ft 12 Breakdown of new BUA not on subdivided lots: Parking (sq ft Sidewalk (sq ft 75573 sf 27645 sf 15376 sf 5672 sf 26880 sf Roof (sq ft Roadway s ft 215004 sf 71993 sf 43779 sf 17073 sf 82159 sf Future (sq ft Other, please specify in the comment box below (sq ft 9920 sf 9920 sf 13 New infiltrating permeable pavement on subdivided lots (sq ft 14 New infiltrating permeable pavement not on subdivided lots (sq ft 15permitting) Existing BUA that will remain (not subject to s ft 16 1 Existing BUA that is already permitted (sq ft 17 Existing BUA that will be removed (sq ft 18 Percent BUA 19.52% 42.1% 43% 49% 40% 19 Design storm inches 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM cu ft 32182 cf 62235 cf 7580 cf 31488 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method Simple Method ONAL INFORMATION ease use this space to provide any additional information about the "22drainagearea(s): 12-Postal Kiosk for additional BUA INFILTRATION SYSTEM 1 Drainage area number 2 1 Minimum required treatment volume (cu ft) ERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes 4 Is the SCM located away from contaminated soils? Yes 5 What are the side slopes of the SCM (H:V or enter "Vertical' for trenches)? 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes 9 lWhat is the method for dewatering the SCM for maintenance? Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comply with General MDC (8)? Yes 12 Does the drainage easement comply with General MDC (9)? Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC 10 ? N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes 16 Does the SCM follow the device specific MDC? Yes 17 Was the SCM designed by an NC licensedprofessional? Yes 18 1 Proposed slope of the subgrade surface (%) 0% 19 jAre terraces or baffles provided? No 20 1Tvpe of pretreatment: Forebay Data 21 Was the soil investigated in the footprint and at the elevation of the infiltrations stem? Yes 22 SHWT elevation (fmsl) 189.00 23 Depth to SHWT per soils report (in) 120 in 24 Ground elevation at boring in soils report (fmsl) 199.00 25 Is a detailed hydrogeologic study attached if the separation is between 1 and 2 feet? N/A 26 ISoil infiltration rate (in/hr) 4.00 27 1 Factor of safety (FS) (2 is recommended): 2.00 Elevations 29 113ottom elevation (fmsl) 199 ft 30 IStorage elevation (fmsl) 204.5 ft 31 1 Bypass elevation (fmsl) 204.5 ft Basins 32 113ottom surface area(ft) 7230 ft 33 Istorage elevation surface area(ft) 15675. ft For Trenches Only 34 Length (ft) 35 Width (ft) 36 Perforated pipe diameter, if applicable (inches) 37 Number of laterals 38 Total length of perforated piping 39 Stone type, if applicable 40 Stone porosity (%) 41 Is stone free of fines? 42 Is the stone wrapped in geotextile fabric? 43 Has at least one inspection port been provided? Volumes/Drawdown 44 IDesign volume of SCM (cu ft) 62235 cf 45 ITime to draw down (hours) 51.6 hrs 46 Please use this space to provide any additional information about the infiltration system(s): Line 26 - The soils report found the infiltration rate of the soil to be 8.0"/hr. A more conservative value of 4.0"/hr was used in the calculations, to account for clogging of the soils that will happen over time. Infiltration 1 9:16 AM 4/12/2023 WET POND 1 11 Drainage area number 1 3 4 21 Minimum required treatment volume (cu ft) 31555 cf 7243 cf 29967 cf NERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes Yes 5 What are the side slopes of the SCM (H:V)? 3:1 3:1 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No No No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes Yes Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) Pump (preferred) Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes Yes Yes 11 Does the maintenance access comply with General MDC (8)? Yes Yes Yes 12 Does the drainage easement comply with General MDC (9)? Yes Yes Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC (10)? N/A N/A N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes Yes Yes 161 Does the SCM follow the device specific MDC? Yes Yes Yes 17 Was the SCM designed b an NC licensedprofessional? Yes Yes Yes WET POND MDC FROM 02H .1053 18 Sizing method used SA/DA SA/DA SA/DA 19 Has a stage/storage table been provided in the calculations? Yes Yes Yes 20 Elevation of the excavated main pool depth (bottom of sediment removal) (fmsl 206.00 189.00 202.00 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 207.00 190.00 203.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 211.50 195.50 206.50 23 Elevation of the permanent pool (fmsl) 212.00 196.00 207.00 24 Elevation of the top of the vegetated shelf (fmsl) 212.50 196.50 207.50 25 Elevation of the temporary pool (fmsl) 213.90 197.50 208.70 26 Surface area of the main permanent pool (square feet) 11390 2950 13155 27 Volume of the main permanent pool (cubic feet) 43138 cf 8526 cf 42764 cf 28 Average depth of the main pool (feet) 4.22 ft 3.66 ft 3.58 ft 29 Average depth equation used Equation 3 Equation 3 Equation 3 301 If using equation 3, main pool perimeter (feet) 423.0 ft 237.0 ft 442.0 ft 31 If using equation 3, width of submerged veg. shelf (feet) 3.0 ft 3.0 ft 3.0 ft 32 Volume of the forebay (cubic feet) 6715 cf 1583 cf 7964 cf 33 Is this 15-20% of the volume in the main pool? Yes Yes Yes 34 Clean -out depth for forebay (inches) 48 in 48 in 48 in 35 Design volume of SCM (cu ft) 32182 cf 7580 cf 31488 cf 36 Is the outlet an orifice or a weir? Orifice Orifice Orifice 371 If orifice, orifice diameter (inches) 2.00 in 1.00 in 2.50 in 38 If weir, weir height (inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 3.59 3.61 2.41 41 Are the inlet(s) and outlet located in a manner that avoids short- circuiting? Yes Yes Yes 42 Are berms or baffles provided to improve the flow path? Yes Yes Yes 431 Depth of forebay at entrance (inches) 60 in 60 in 60 in 44 Depth of forebay at exit (inches) 54 in 54 in 54 in 45 Does water flow out of the forebay in a non -erosive manner? Yes Yes Yes 46 Width of the vegetated shelf (feet) 6 ft 6 ft 6 ft 47 Slope of vegetated shelf (H:V) 6:1 6:1 6:1 48 Does the orifice drawdown from below the top surface of the permanentpool? Yes Yes Yes 49 Does the pond minimize impacts to the receiving channel from the 1- r, 24-hr storm? Yes Yes Yes 50 Are fountains proposed? (If Y, please provide documentation that MDC(9) is met. No No No 51 Is a trash rack or other device provided to protect the outlet system? Yes Yes Yes 52 Are the dam and embankment planted in non -clumping turf grass? Yes Yes Yes 53 Species of turf that will be used on the dam and embankment Hybrid Bermuda Hybrid Bermuda Hybrid Bermuda 54 Hasa planting plan been provided for the vegetated shelf? Yes Yes Yes ADDITIONAL INFORMATION 55 Please use this space to provide any additional information about the wet pond(s): Wet Pond 1 9:16 AM 4/12/2023