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Home My WebLink AboutSW6210303_Ez Supplement Form 2_20210329SUPPLEMENT-EZ COVER PAGE I FORMS LOADED PROJECT INFORMA11ION 1 1 Project Name Watson Ridge 2 Project A a (ac) 39.625 3 Coastal Welland Area (ac) 4 Surface Water Area (ac) 0.429 5 1 Is this project High or Low Density? High 6 � Does this project use an off -site SCIVI? No COMPUANCE VkqTH 02H.IWX4) 7 Width of veget 3! 30 8 lWill the vegetated setback remain vegetated? Yes - ---- 9 If BILIA is proposed in the setback, does it meet NCAC 021-110�4 c,1E_ No lo Its strearnbank stabilization proposed on this project? No NUMBER AND TYPE OF SCMs: 11 Infiltration System 2 12 Bioretention Celi 0 13 Wet Pond 1 14 Stormwater Wetiand a 16 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 ImperviousSurfage (Dlq�__ 0 21 Treatment Swale 0 22 ond 0 -D 23 StormFilter 0 24 Silva Cell 0 25 Bayfilter 0 26 Filterra 0 I FORMS LOADED 0WOMRCERTWWATION 27 �Narne and Title: Matt Lowder, PE 28 lOrganization: Triangle Site sign, PILLC 29 Street address- 4DO4 Barrett Drive, Suite 101 30 !City, S ate, Zip: Raleigh, NC 27609 31 1 Phone number(s): 91"53-6570 32 1 Email: mlowder@triangles4odesign.com 10411fication stmernall I oertify, under penalty of law that ibis Supplemeryt-EZ form and all supporting i. ifon. were prepared under rny direction or supervision; VW the lnforma*)n provided in the form is, to the beM of my knowledge and boW trus, aocurale, and complete; and tat the engineering plans, sp�fions. operation and maintenar4s, agreements and other suppoiAng Information are consistanit with the information provided have. % Seal Signalure of Designer Date DRAINAGE AREAS I 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 5 Is allipart of this project subject to previous rule versions? No I FORMS LOADED DRAINAGE AREA INFORKATON EnUre Sift 1 2 3 4 Type of SCM - Infiltration Basin Infiltration Basin Wet Pond 5 Total drainage area (sq ft) 1010204 262994 425090 322120 6 Onsite drainage area (sq ft) 987169 239959 425090 322120 7 Oftite drainage area (sq ft) 23035 23035 8 Total BOA in project (sq ft) 230951 73115 sf 99538 sf 58298 sf 9 New BUA on subdivided lots (subject to permitting) (sq ft) 10 New BUA not on subdivided lots (subject to permitting) (sf)i 11 Offsite BUA (sq ft) 7686 76M sf 12 Breakdown of new BUA not on subdivided lots: Parking (sq It) Sidewalk (sq ft) Roof (sq ft) 168000 48000 Sf 72000 sf 48000 sf Roadway (sq ft) 55265 17429 sf 27538 sf 10298 sf Future (sq ft) Other, please specify in the comment box below (sq ft) 13 New infiltrating permeable pavement on subdivided lots (sq ft) 14 New infiltrating permeable pavement not on subdivided �ots (sq ft) 15 Existing BUA that will remain (not subject to permitting) (sq ft) 16 1 Existing BUA that is already permitted (sq ft) 17 Existing BUA that will be removed (sq ft) 18 Percent BUA 28% 23% 18% 19 �s Design storm Ciqq�e 1.0 in 1.0 in 1.0 in 20 Design volume of SCIVI (cu ft) 6579 cf 9237 ef 5715 ef 21 Calculation method for design volume Simple Method Simple Method Simple Method ADDrrK)NAL INFORMATION I 22 IPlease use this space to provide any additional information about the drainage area(s)� Inilittration Basin #11 - there is oftite drainage area from the Lee County portion of the overall development. I INFILTRATION SYSTEM Drainage area number 1 2 2 1 Minimum required treatment volume (cu ft) 6579 Ct 9237 ef 3 1 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 What are the side slope$ of the SCM (H:V or enter "Vertical" for 5 trenches)? 3A 3:1 6 Does the SCM have retaining walls. gabion walls or other engineered side slopes? No No 7 Are the inlets, outlets, and receiving stream protected from erosion (1 0-yea r storm)? Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes Yes 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 13 If the SCM is on a single family lot, does (411?) the plat comply with General MDC (10)? NIA N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes Yes 15 Is there an O&M Plan that complies Wth General MDC (12)? Yes Yes 16 1 Does the SCIM follow the device specific MDC? Yes Yes 17 lWas the SCM desioned bv an NC licensed professional? Yes yes 18 Proposed slope of the subgrade surface(%) 19 Are terraces or battles provided? No No 20 ITyp_e_of pretreatment: Forebay Forebay C.ilk 1110. 21 Was the soil investigated in the footprint and at the elevation of the infiltration system? Yes Yes 22 SHWT elevation (fmsl) 365.50 332.00 23 Depth to SHWT per soils report (in) 72.00 56.00 24 Ground elevation at boring in soils report (fmsl) 371,50 336.60 25 tio 7 Is a detailed hydrogeologic study attached if the separa n is between 1 and 2 feet? Yes Yes 26 Soil infiltration rate (in/hr) 9.00 10.0 27 Factor of safety (FS) (2 is reGommended)� 2.00 7 =_00 1j=1A%wjftVnnC 29 Bottom elevation (fmsi) 371 ft 336 ft 3o Storage elevation (fmsl) 372� ft 337. ft 31 Bypass elevation (frnsl) 373.2 fl 338.8 ft 34 Length (fl) 35 ............ Width (ft) 36 Perforated pipe diame ter, if applicable (inches) 37 Number of laterals 38 Total length of perforated piping 39 Stone type, if applicable 40 Stone porosily (%) I - - 1 41 is stone free of fines? 42 Is the stone wrapped in geotextile fabric? 43 Has at least one inspection port been provided? VolmimatDiawdolm 44 IDesign volume ofSCM (cu ft) 6579 af 9237 cf 45 1 Time to draw down (hours) 72 hrS 72 hrs 46 Please use this space to provide any additional information about the linfiltration syslem(s): I Infiltration 2:35 PM 3/4/2021