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Home My WebLink AboutSW3230302_Supplement-EZ Form_20230627 SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION 1 Project Name DAVIS VILLAGE 2 Project Area(ac) 60.38 3 Coastal Wetland Area(ac) 4 Surface Water Area(ac) 0.91 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)? 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 2 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 I 27 'Name and Title: BRYAN C.LINTON,PE 28 Organization: PLOTT HOUND ENGINEERING 29 Street address: 146 Valley Glen Drive 30 City,State,Zip: Waxhaw,NC 28173 31 Phone number(s): 704-439-6521 32 Email: BRYAN@PLOTTHOUNDENGINEERING.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 ��\\\\111111111///cif Q�a1ESS% q•.9% 1 _ Signature of Desi ner ... '-1.4.-- 44'4.- 042077 W2.0/2 3 HGINE� .\\�� // )/AI N11LIN."\\�' JUNE 20, 2023 Seal Date DRAINAGE AREAS k1 Is this a high density project? Yes 2 If so, number of drainage areas/SCMs 3 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 IL Entire Site 1 2 3 4 Type of SCM Wet Pond Sand Filter Sand Filter 5 Total drainage area (sq ft) 2,630,153 1,306,800 326,700 217,913 6 Onsite drainage area (sq ft) 1,655,393 sf 1,306,800 326,700 sf 217,913 sf 7 Offsite drainage area (sq ft) 0 sf 0 sf 0 sf 0 sf 8 Total BUA in project(sq ft) 1007854 sf 641698 sf 145763 sf 104883 sf New BUA on subdivided lots(subject to permitting) 9 (sq ft) 667120 sf 458500 sf 42000 sf 65360 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 340734 sf 183198 sf 103763 sf 39523 sf 11 Offsite BUA(sq ft) 0 sf 0 sf 0 sf 0 sf 12 Breakdown of new BUA not on subdivided lots: - Parking (sq ft) 7147 sf 0 sf 0 sf 7147 sf -Sidewalk(sq ft) 79800 sf 48210 sf 19320 sf 8520 sf - Roof(sq ft) 0 sf 0 sf 0 sf 0 sf - Roadway(sq ft) 223440 sf 134988 sf 54096 sf 23856 sf - Future (sq ft) 30347 sf 0 sf 30347 sf 0 sf -Other, please specify in the comment box below (sq ft) 0 sf 0 sf 0 sf 0 sf New infiltrating permeable pavement on subdivided 13 lots (sq ft) 0 sf 0 sf 0 sf 0 sf New infiltrating permeable pavement not on 14 subdivided lots (sq ft) 0 sf 0 sf 0 sf 0 sf Existing BUA that will remain (not subject to 15 permitting) (sq ft) 0 sf 0 sf 0 sf 0 sf 16 Existing BUA that is already permitted (sq ft) 0 sf 0 sf 0 sf 0 sf 17 Existing BUA that will be removed (sq ft) 0 sf 0 sf 0 sf 0 sf 18 Percent BUA 38% 49% 45% 48% 19 Design storm (inches) 1 in 1 in 1 in 20 Design volume of SCM (cu ft) 53470 cf 9843 cf 6562 cf 21 Calculation method for design volume Simple Method 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 I 2 Minimum required treatment volume(cu ft) 53740 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? Drawdown Orifice 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 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 licensed professional? 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 550.00 removal)(fmsl) _ 21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 551.00 _ 22 Elevation of the bottom of the vegetated shelf(fmsl) 555.00 23 Elevation of the permanent pool(fmsl) 555.50 24 Elevation of the top of the vegetated shelf(fmsl) 556.00 25 Elevation of the temporary pool(fmsl) 557.00 26 Surface area of the main permanent pool(square feet) 26575 27 Volume of the main permanent pool(cubic feet) 103019 cf 28 Average depth of the main pool(feet) 3.70 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) 24176 cf 33 Is this 15-20%of the volume in the main pool? Yes 34 Clean-out depth for forebay(inches) 54 in 35 Design volume of SCM(cu ft) 54973 cf 36 Is the outlet an orifice or a weir? Orifice 37 If orifice,orifice diameter(inches) 4 in 38 If weir,weir height(inches) 39 If weir,weir length(inches) 40 Drawdown time for the temporary pool(days) 3.7 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? Yes 43 Depth of forebay at entrance(inches) _ 66 in 44 Depth of forebay at exit(inches) 60 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 Tall Fescue 54 Has a planting Ian been provided for the vegetated shelf? Yes ADDITIONAL INFOR J. Please use this space to provide any additional information about 55 the wet pond(s): Wet Pond 3 6:20 PM 6/20/2023 SAND FILTER 1 Drainage area number 2 3 2 Minimum required treatment volume(cu ft) 9843 sf I 6562 sf GENERAL MDC FROM 02H.1050 3 Is the SCM sized to treat the SW from all surfaces at build-out? Yeo Yeo 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 No No engineered 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 N/A N/A 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 designed by an NC licensed professional? Yes Yes SAND FILTER MDC FROM 02H.1056 18 SHWT elevation(fmsl) 19 Type of sand filter(open or closed) Open Open 20 If closed,will the filter will be pre-cast or pour-in-place? _ 21 If closed,top of grate elevation(fmsl) _ 22 Is this sand filter designed to attenuate peak flows? Yes Yes Sediment Chamber 23 Volume that can be retained in the sediment chamber(cubic feet) 23154 cf 17204 cf _ 24 Will there be a permanent pool in the sediment chamber? No No _ 25 Bottom of the sediment chamber(fmsl) _ 575.00 550.00 _ 26 Area of the sediment chamber(square feet) 9279 sf 7937 sf 27 Physical depth of the sediment chamber(inches) 36 in 36in 28 Ponding depth in the sediment chamber,above any permanent 36 in 36in pool(inches) 29 Elevation of top of weir between chambers(fmsl) 578 553 Sand Chamber 30 Volume that can be retained in the sand chamber(cubic feet) 4934 cf 4652 cf 31 Bottom of the sand chamber(fmsl) 575.00 550.00 32 Area of the sand chamber(square feet) 1334 sf 913 sf 33 Physical depth of the sand chamber(inches) 48 in 54 in 34 Ponding depth in the sand chamber,above the sand surface 30 in 36 in (inches) _ 35 Elevation of the bypass device(fmsl) 577.5 553 _ 36 Type of bypass device 6"x36"orifice 12"x24"orifice_ 37 Mechanism for distributing flow over the sand surface 5'grassed level grassed level spreader spreader _ 38 Sand specification for sand chamber med.aggregate med.Aggregate sand ASTM C33 sand ASTM C33_ 39 Depth above underdrain pipe(inches) 12 in.min 12 in min. 40 Will the media be maintained to drain at least two inches per hour at Yes Yes the sand surface? _ 41 Is at least one clean-out pipe provided at the low point of each Yes Yes underdrain line? _ 42 Will clean-out pipes be capped? Yes Yes ADDITIONAL INFORMATION 43 Please use this space to provide any additional information about the sand filter(s): Sand Filter 4 6:20 PM 6/20/2023