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HomeMy WebLinkAboutSW6231205_Supplement-EZ Form_20240416 SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION 1 Project Name Gardner Farms 2 Project Area(ac) 46.34 3 Coastal Wetland Area(ac) 2.13 4 Surface Water Area(ac) N/A 5 Is this project 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 0 12 Bioretention Cell 0 13 Wet Pond 2 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting(RWH) 0 18 Green Roof 0 19 Level Spreader-Filter Strip(LS-FS) 0 20 Disconnected Impervious Surface(DIS) 0 21 Treatment Swale 0 22 Dry Pond 0 23 StormFilter 0 24 Silva Cell 0 25 Bayfilter 0 26 Filterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 Name and Title: Jeremy Keeny,Vice President PE,PLS 28 Organization: Morris&Ritchie Associates 29 Street address: 530 Hinton Pond Road 30 City,State,Zip: Knightdale,NC 27545 31 Phone number(s): 984-200-2103 32 Email: Jkeeny@mragta.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 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs _ 2 3 Does this project have low density areas? _ No 4 If so,number of low density drainage areas _ 0 Is all/part of this project subject to previous rule 5 versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 1 2 4 Type of SCM N/A Wet Pond Wet Pond _ 5 Total drainage area(sq ft) 2,111,353 _ 1615867 463049 6 Onsite drainage area(sq ft) 1896400 _ 1433351 463049 7 Offsite drainage area(sq ft) 182516 182516 0 8 Total BUA in project(sq ft) 1167876 sf _ 879190 sf 284112 sf New BUA on subdivided lots(subject to 9 permitting)(sq ft) 680000 sf 490200 sf 189800 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 305360 sf 206474 sf 94312 sf 11 Offsite BUA(sq ft) 182516 sf 182516 sf sf 12 Breakdown of new BUA not on subdivided lots: -Parking(sq ft) N/A N/A N/A -Sidewalk(sq ft) 86162 sf 60548 sf 21040 sf -Roof(sq ft) N/A N/A N/A -Roadway(sq ft) 203294 sf 145926 sf 57368 sf -Future(sq ft) 15904 sf sf 15904 sf -Other,please specify in the comment box below(sq ft) N/A N/A N/A New infiltrating permeable pavement on 13 subdivided lots(sq ft) N/A N/A N/A New infiltrating permeable pavement not on 14 subdivided lots(sq ft) N/A N/A N/A Existing BUA that will remain(not subject to 15 permitting)(sq ft) sf sf sf 16 Existing BUA that is already permitted(sq ft) sf sf sf 17 Existing BUA that will be removed(sq ft) sf sf sf 18 Percent BUA 55% 58% 72% 19 Design storm(inches) 1.0 in 1.0 in 20 Design volume of SCM(cu ft) 78459 cf 36354 cf 21 Calculation method for design volume I Simple Method Simple Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): WET POND 1 Drainage area number 1 1 (SCM A) L 2(SCM B) I 2 Minimum required treatment volume(cu ft) 76919 cf 26979 cf GENERAL MDC FROM 02H.1050 3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes 5 What are the side slopes of the SCM(H:V)? 3:1 3:1 6 Does the SCM have retaining walls,gabion walls or other engineered Yes No side slopes? 7 Are the inlets,outlets,and receiving stream protected from erosion Yes Yes (10-year storm)? 8 Is there an overflow or bypass for inflow volume in excess of the Yes Yes design volume? 9 What is the method for dewatering the SCM for maintenance? Pump(preferred) Pump(preferred) 10 If applicable,will the SCM be cleaned out after construction? Yes Yes 11 Does the maintenance access comply with General MDC(8)? Yes Yes 12 Does the drainage easement comply with General MDC(9)? Yes Yes If the SCM is on a single family lot,does(will?)the plat comply with 13 No No General MDC(10)? 14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes 15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes 16 Does the SCM follow the device specific MDC? Yes Yes 17 Was the SCM desi ned b an NC licensed rofessional? Yes Yes WET POND MDC FROM 02H.1053 18 Sizing method used SA/DA SA/DA 19 Has a stage/storage table been provided in the calculations? Yes Yes 20 Elevation of the excavated main pool depth(bottom of sediment 257.00 273.00 removal)(fmsl) 21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 257.50 273.50 22 Elevation of the bottom of the vegetated shelf(fmsl) 263.00 279.00 23 Elevation of the permanent pool(fmsl) 264.00 279.50 24 Elevation of the top of the vegetated shelf(fmsl) 264.00 280.00 25 Elevation of the temporary pool(fmsl) 264.00 279.50 26 Surface area of the main permanent pool(square feet) 28015 26098 27 Volume of the main permanent pool(cubic feet) 137468 cf 121062 cf 28 Average depth of the main pool(feet) 4.91 ft 4.64 ft 29 Average depth equation used Equation 2 Equation 2 30 If using equation 3,main pool perimeter(feet) N/A N/A 31 If using equation 3,width of submerged veg.shelf(feet) N/A N/A 32 Volume of the forebay(cubic feet) 25553 cf 23031 cf 33 Is this 15-20%of the volume in the main pool? Yes Yes 34 Clean-out depth for forebay(inches) 66 in 66 in 35 Design volume of SCM(cu ft) 78459 cf 36354 cf 36 Is the outlet an orifice or a weir? Orifice Orifice 37 If orifice,orifice diameter(inches) (2)3 in 3 in 38 If weir,weir height(inches) N/A N/A 39 If weir,weir length(inches) N/A N/A 40 Drawdown time for the temporary pool(days) 3.7 4.5 41 Are the inlet(s)and outlet located in a manner that avoids short- Yes Yes circuiting? 42 Are berms or baffles provided to improve the flow path? Yes Yes 43 Depth of forebay at entrance(inches) 78 in 78 in 44 Depth of forebay at exit(inches) 72 in 72 in 45 Does water flow out of the forebay in a non-erosive manner? Yes Yes 46 Width of the vegetated shelf(feet) 6 ft 6 ft 47 Slope of vegetated shelf(H:V) 6:1 6:1 48 Does the orifice drawdown from below the top surface of the Yes Yes permanent pool? 49 Does the pond minimize impacts to the receiving channel from the 1- Yes Yes yr,24-hr storm? 50 Are fountains proposed?(If Y,please provide documentation that No No MDC(9)is met.) 51 Is a trash rack or other device provided to protect the outlet system? Yes Yes 52 Are the dam and embankment planted in non-clumping turf grass? Yes Yes 53 Species of turf that will be used on the dam and embankment Hybrid Bermuda Hybrid Bermuda 54 Has a planting plan been provided for the vegetated shelf? Yes r Yes ADDITIONAL INFORMATION 55 Please use this space to provide any additional information about the wet pond(s): SCM A will contain two drawdown orifices.Two drawdown orificies and outlet pipes are being utilized to help with outflow restrictions of using a singular outlet barrel. SCM B will have a 2.5"drawdown orifice. 2