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HomeMy WebLinkAboutSW6220101_Supplement-EZ Form_20230831 SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION 1 Project Name Woodshire Subdivision Phase 7 2 Project Area(ac) 32.96 3 Coastal Wetland Area(ac) 0 4 Surface Water Area(ac) 0 5 Is this project High or Low Density? Both High and Low Density 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)? N/A 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMs: 11 Infiltration System 12 Bioretention Cell 13 Wet Pond 1 14 Stormwater Wetland 15 Permeable Pavement 16 Sand Filter 17 Rainwater Harvesting(RWH) 18 Green Roof 19 Level Spreader-Filter Strip(LS-FS) 20 Disconnected Impervious Surface(DIS) 21 Treatment Swale 22 Dry Pond 23 StormFilter 24 Silva Cell 25 Bayfilter 26 Filterra FORMS LOADED DESIGNER CERTIFICATION 27 Name and Title: C.Scott Brown,PE 28 Organization: 4D Site Solutions,Inc. 29 Street address: 409 Chicago Drive-Suite 112 30 City,State,Zip: Fayetteville,NC 28306 31 Phone number(s): 910-426-6777 32 Email: sbrown@4dsitesolutions.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. Designer Signature of Designer Seal Date DRAINAGE AREAS r5 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs _ 1 3 Does this project have low density areas? _ Yes 4 If so,number of low density drainage areas _ 1 Is all/part of this project subject to previous rule versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 1 LD 1 4 Type of SCM Wet Pond Low Density 5 Total drainage area(sq ft) 1435900 829,144 622,719 _ 6 Onsite drainage area(sq ft) 1435900 813,181 622,719 7 Offsite drainage area(sq ft) 15963 15,963 0 8 Total BUA in project(sq ft) 412980 sf 388943 sf 40000 sf New BUA on subdivided lots(subject to 9 permitting)(sq ft) - 268000 sf 228000 sf 40000 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 144980 sf 144980 sf sf 11 Offsite BUA(sq ft) 15963 sf sf 12 Breakdown of new BUA not on subdivided lots: -Parking(sq ft) -Sidewalk(sq ft) 15984 sf 15984 sf -Roof(sq ft) -Roadway(sq ft) 107814 sf 107814 sf -Future(sq ft) -Other,please specify in the comment box below(sq ft) 21182 sf 21182 sf New infiltrating permeable pavement on 13 subdivided lots(sq ft) New infiltrating permeable pavement not on 14 subdivided lots(sq ft) Existing BUA that will remain(not subject to 15 permitting)(sq ft) 16 Existing BUA that is already permitted(sq ft) 17 Existing BUA that will be removed(sq ft) 18 Percent BUA 29% 47% 6% 19 Design storm(inches) 1.0 in 20 Design volume of SCM(cu ft) 58318 cf 21 Calculation method for design volume Simple ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): The"other"impervious included above is the water surface of the pond WET POND 1 Drainage area number 1 I 2 Minimum required treatment volume(Cu ft) 32625 cf GENERAL 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)? 3:1 Does the SCM have retaining walls,gabion walls or other 6 engineered side slopes? No 7 Are the inlets,outlets,and receiving stream protected from erosion Yes (10-year storm)? 8 Is there an overflow or bypass for inflow volume in excess of the Yes design volume? 9 What 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 If the SCM is on a single family lot,does(will?)the plat comply with 13 N/A General MDC(10)? 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 desi ned b an NC licensed rofessional? Yes WET POND MDC FROM 02H.1053 18 Sizing method used SA/DA 19 Has a stage/storage table been provided in the calculations? Yes 20 Elevation of the excavated main pool depth(bottom of sediment 282.00 removal)(fmsl) 21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 283.00 22 Elevation of the bottom of the vegetated shelf(fmsl) 286.50 23 Elevation of the permanent pool(fmsl) 287.00 24 Elevation of the top of the vegetated shelf(fmsl) 287.50 25 Elevation of the temporary pool(fmsl) 289.31 26 Surface area of the main permanent pool(square feet) 16436 27 Volume of the main permanent pool(cubic feet) 53824 cf 28 Average depth of the main pool(feet) 3.30 ft 29 Average depth equation used Equation 2 30 If using equation 3,main pool perimeter(feet) 31 If using equation 3,width of submerged veg.shelf(feet) 32 Volume of the forebay(cubic feet) 9711 cf 33 Is this 15-20%of the volume in the main pool? Yes 34 Clean-out depth for forebay(inches) 12 in 35 Design volume of SCM(cu ft) 58318 cf 36 Is the outlet an orifice or a weir? Orifice 37 If orifice,orifice diameter(inches) 3.5 in 38 If weir,weir height(inches) 39 If weir,weir length(inches) 40 Drawdown time for the temporary pool(days) 2.4 41 Are the inlet(s)and outlet located in a manner that avoids short- Yes circuiting? 42 Are berms or baffles provided to improve the flow path? No 43 Depth of forebay at entrance(inches) 60 in 44 Depth of forebay at exit(inches) 48 in 45 Does water flow out of the forebay in a non-erosive manner? Yes 46 Width of the vegetated shelf(feet) 6 ft 47 Slope of vegetated shelf(H:V) 6:1 48 Does the orifice drawdown from below the top surface of the Yes permanent pool? 49 Does the pond minimize impacts to the receiving channel from the 1- Yes yr,24-hr storm? 50 Are fountains proposed?(If Y,please provide documentation that No MDC(9)is met.) 51 Is a trash rack or other device provided to protect the outlet system? Yes 52 Are the dam and embankment planted in non-clumping turf grass? Yes 53 Species of turf that will be used on the dam and embankment _ Bermuda Grass 54i Has a planting plan been provided for the vegetated shelf? Yes ADDITIONAL INFORMATION Please use this space to provide any additional information about 55 the wet pond(s): Wet Pond 1 2:12 PM 8/31/2023 LOW DENSITY DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 02H.1003 1 Is project below density thresholds set forth in the applicable stormwater rule? Yes 2 Does project maximize dispersed flow and minimize channelization of flow? Yes 3 Has the use of piping been minimized per.1003(2)(c)? Yes 4 Side slopes of the vegetated conveyances(H:V) 3:1 5 Maximum velocity in the vegetated conveyances during the 10-year storm? 2.72 6 Are curb outlet swales proposed? No 7 Maximum longitudinal slope of curb outlet swale(s)(%) 8 Bottom width of curb outlet swale(s)(feet) 9 Maximum side slope of curb outlet swale(s)(H:V) 10 Minimum length of curb outlet swale(s)(feet) 11 Are treatment swales used instead of curb outlet swales? 12 Is stormwater released at the edge of the setback as dispersed flow? Yes 13 Have stormwater outlets been designed to prevent downslope erosion? Yes 14 Are variations to rule.1003 proposed? No ADDITIONAL INFORMATION 15 Please use this space to provide any additional information about this low density project: Drainage Pervious Swale BUA Q Slope V,,,ow V,cto„ Flow depth Area area (ac) C (cfs) (%) (fps) (fps) (ft) (ac) (ac) 1 1.73 0.40 1.33 0.45 4.08 2.30 4.50 2.72 0.71 2 12.06 2.78 9.28 0.45 28.54 0.50 4.50 2.50 1.79 3 4 5 s_ 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30