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HomeMy WebLinkAboutSW8091003_CURRENT PERMIT_20110308STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 0cW)03 DOC TYPE Al CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE 2o1 (3, O3 YYYYMMDD �+ ;Aw NC®ENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue Coleen H. Sullins Governor Director March 8, 2011 Mr. Jim McDaniel, Director New Hanover County Parks 230 Government Center Drive, Suite 120 Wilmington, NC 28403 Subject: Approved Plan Revision Smith Creek Park Stormwater Project No. SW8 091003 New Hanover County Dear Mr. McDaniel: Dee Freeman Secretary On January 27, 2011, the Wilmington Regional Office received a plan revision for Stormwater Management Permit Number SW8 091003. The revisions include an increase in the building square footage as well as the addition of a dumpster pad, sewer lift station, and sidewalks. These revisions increase the permitted impervious area by 2,110 square feet to 146,919 square feet and reduce the allocated future impervious area to 442,437 square feet. It has been determined that a formal permit modification is not required for the proposed changes. We are forwarding you an approved copy of the applicable revised plans sheets for your files. Please replace the old approved plan sheets with the new ones. Please be aware that all terms and conditions of the permit issued on April9, 2010, remain in full force and effect. Please also understand that the approval of this revision to the approved plans for the subject State Stormwater Permit is done on a case -by -case basis. Any other changes to this project must be approved through this Office prior to construction. The issuance of this plan revision does not preclude the permittee from complying with all other applicable statutes, rules, regulations or ordinances which may have jurisdiction over the proposed activity, and obtaining a permit or approval prior to construction. If you have any questions concerning this matter, please do not hesitate to call Georgette Scott or me at (910) 796-7215. Sincerely, Christine Nelson Environmental Engineer GDS\can: S:\WQS\STORMWATER\Permits & Projects\2009\091003 LD\2011 03 permit _pr 091003 cc: Brian Riley, Thomas & Hutton Engineering Co. New Hanover County Building Inspections Wilmington Regional Office Wilmington Regional Office 127 Cardinal Drive Extension, Wilmington, North Carolina 28405 One 1.. Phone: 910.796.72151 FAX 910-350-20041 Customer Service: 1-877623-6748 N o rt h Carcol i n a Internet: www.nmaterquality.org AW=flra , An Equal Opportunity 1 Affirmative Action Employer 1 1 J DWQ USE ONLY IF Dale Received Pee Paid (express, only) Permit Number State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT PLAN REVISION APPLICATION FORM Thisform may bephotocopiedfor useas an original 1. GEN ERAL IN FORMATION I. Stormwater Management Permit Number: SW8-091003 2. Project Name: 3. Permit flolder'sname(specily the name oflhe corporation, individual, etc.): New Hanover County - Parks Department 4. Print Owner/ Signing Official's name and title (person legally responsible for permit): Jim McDaniel/ Director 5. Mailing Address for person listed in item 2 above: 230 Government Center Drive, Suite 120 City:Wilmineton State:NC 7ip:28403 Phone: (910 ) 798-7620 Fax: (910 1 798-7621 Em a il:im cda n iel an hcLov.coom IL PLAN REVISION INFORMATION 1. Summarize the plan revision proposed (attach additional pages if needed): Revised buildine, square footaec, add dumpster pad, additional sidewalk,& sewer lift station resultine in Phase 1 BUA increase of 2.110 sf. Future DOA reduced by same amount Ill. SUBMITTAL REQUIREMENTS Only complete application packages will he accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the items listed below. The complete application package should be submitted to the DWQ Office that issued the permit. I. Please indicate that you have provided the following required information by initialing in the space provided next to each item. • Original & / copy of the Plan Revision Application Form • Two (2) copies of revised plans (must be revisions oforgginal approved plan sheet(s)) If applvine for Express review (only availablein 20cocuyal counties): • Application fee of $500.00 (madepavable to NCDENR) V1. APPLICANT"SCERTIFICATION I, (print or type name of erson listed in General btfam noon. item 3) Jim ,4h;D.mie1/Di rr.rtor , certify that I have aut orized these plan revisions and that the information included on this plan revision application is, to the Vest of my I^owledge, correct and complete. Signatu Plan Revision Forgl Rev 13July2010 Page I of I Date: /' Z-1' G/ Permit No. J��O 09���✓ (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM LOW DENSITY SUPPLEMENT This form may be photocopied for use as an original A low density project is one that meets the appropriate criteria for built upon area and transports stormwater runoff primarily through vegetated conveyances. Low density projects should not have a discrete stormwater collection system as defined by 15A NCAC 211 .1002(18). Low density requirements and density factors can be found in Session Law 2008-211, 15A NCAC 2I-I .1000, Session Law 2006-246, and the DWQ BMP Manual. Curb and gutter systems are allowed provided they meet the requirements in 15A NCAC 2H .1008(g). I. PROJECT INFORMATION Project Name : New Hanover County Park -Smith Creek Park Contact Person: William "Neal" Lewis Phone Number: ( 910 )798-7620 Number of Lots: Allowable Built Upon Area (BUA) Per Lot*:589.356 Number of Dwelling Units Per Acre**:N/A Low Density Development (check one): ® without curb & gutter ❑ with curb & gutter, outlets to (check one): ❑ Swales ❑ Vegetated Area *If lot sizes are not uniform, attach a table indicating the number of lots, lot sizes and allowable built upon area for each lot. The attachment must include the project name, phase, page numbers and provide area subtotals and totals. BUA shall be shown in units of square feet. **(Phase 11 Post -Construction (non -SA) only) Ii. BUILT UPON AREAY Refer to DWQ's forms and applications website for specific language that must be recorded in thiC deedO� restrictions for all subdivided projects. (http://h2o.enr.state.nc.us/su/bmp_forms.htm) ry)O Complete the following calculation in the space provided below where: SA Site Area -the total project area above Mean high Water. OC • DF Density Factor - the appropriate percent built upon area divided by 100. • RA Road Area - the total impervious surface occupied by roadways. • OA Other Area - the total area of impervious surfaces such as clubhouses, tennis courts, sidewalks, etc. • No. of Lots - the total number of lots in the subdivision. • BUA per Lot - the computed allowable built upon area for each lot including driveways and impervious surfaces located between the front lot line and the edge of pavement. • Total allowable lot BUA - the computed allowable built upon area for all lots combined. • Total BUA from lot listing - the sum of built upon area allocated for each lot on the list of non -uniform lots. Form SW401-Low Density-Rev.3-2/10/09 Page I of 4 Calculation: For uniform lot sizes: N/A (SA: ft2 x DF: ) - (RA: ft') - (OA: ft2) = BUA per Lot = ft2 (No of Lots: ) For non -uniform lot sizes: N/A a. (SA: ft2 x DF: ) - (RA: ft') - (OA: ft") = Total allowable lot BUA = ft2 Max BUA = 2,455,650 sf X .24 = 589,356 sf b. Total BUA from lot listing: sf. b must be < a Proposed BUA = 145,000 sf< 589,356 sf III. DESIGN INFORMATION Complete the following table. If additional space is needed the information should be provided in the same format as Table 1 and attached to this form. Rainfall intensity data can be found in Appendix 8.03 of the State of North Carolina Erosion and Sediment Control Planning and Design Manual or at http://hdsc.nws.iioaa.gov/lidsc/pfds/ Table 1. Swale desien information based on the 10-vear storm_ Swale No. Drainage Area ac Impervious Area ac Grassed Area ac C Q efs Slope (% Vaiiow (fps) Vactual (fps) Flow Depth li) 1 0.59 0.20 0.39 0.42 2.41 0.50 3.5 1.68 0.69 2 0.46 0.10 0.36 0.32 1.08 0.75 3.50 1.60 0.48 3 4.00 0.34 3.66 0.22 4.44 0.50 3.50 2.11 0.84 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Form SW401-Low Density- Rev.3-2/10/09 Page 2 of 4 IW REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the North Carolina Administrative Code Section 15A NCAC 2H .1000, NCDENR BMP Manual (2007), Session Law 2006-246, and Session Law 2008-21 I. Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to indicate that the following requirements have been met and supporting documentation is provided as necessary. If the applicant has designated an agent on the Stormwater Management Permit Application Form, the agent may initial below. If any item is not met, then iustitieation must be attached. Only Complete items n through p for projects with curb outlets. Page/Plan Initials Sheet No. C3 a. t For projects in the 20 coastal counties: Per NCAC 21-1.1005, a 50 foot wide vegetative buffer is provided adjacent to surface waters. For Redevelopment projects, a 30' wide vegetative buffer adjacent surface waters is provided. N/A b. 'For HQW or ORW projects outside the 20 coastal counties: A 30 foot wide vegetative buffer is provided adjacent to surface waters. C3 c. t For Phase 11 Post -Construction projects: All built upon area is located at least 30 feet landward of all perennial and intermittent surface waters. N/A d. Deed restriction language as required on form SWU-101 shall be recorded as a restrictive covenant. A copy of the recorded document shall be provided to DWQ within 30 days of platting and prior to the sale of any lots. C3 e. Built upon area calculations are provided for the overall project and all lots. N/A f. Project conforms to low density requirements within the ORW AEC. (if applicable per 15A NCAC 21-1 .1007) C23 g. Side slopes of swales are no steeper than 3:1; or no steeper than 5. l for curb outlet swales. C14 It. Longitudinal slope of swales is no greater than 5%; for non -curb outlet projects, calculations for shear stress and velocity are provided if slope is greater than 5%. Caics i. At a minimum, swales are designed to carry the 10 year storm velocity at a non -erosive rate. Calcs j. Swales discharging to wetlands are designed to flow into and through the wetlands at a non - erosive velocity (for this flow requirement into wetlands, non -erosive is velocity < 2 ft/s). C8 & C23 k. Swale detail and permanent vegetation is specified on the plans. C23 I. Swale detail provided on plans; includes grass type(s) for permanent vegetative cover. N/A m.Swales are located in recorded drainage casements. N/A n.tt Length of swale or vegetated area is at least 100 feet for each curb outlet. N/A o.tt The system takes into account the run-off at ultimate built -out potential from all surfaces draining to the system (delineate drainage area for each Swale). N/A p.tt Curb outlets direct flow to a swale or vegetated area. t Projects in the Neuse, Tar -Pamlico, Catawba River basins, and Randleman Lake may require additional butters. tt Only complete these items for projects with curb outlets. Fonn SW401-Low Density-12ev.3-2/10/09 Page 3 of 4 V. SWALE SYSTEM MAINTENANCE REQUIREMENTS I. Mowing will be accomplished as needed according to the season. Grass height will not exceed six inches at any time; and grass will not be mowed too close to the ground or "scalped". 2. Swales will be inspected monthly or after every runoff producing rainfall event for sediment build-up, erosion, and trash accumulation. 3. Accumulated sediment and trash will be removed as necessary. Swales will be reseeded or sodded following sediment removal. 4. Eroded areas of the Swales will be repaired and reseeded. Swales will be revegetated as needed and in a timely manner based on the monthly inspections. Side slopes must be maintained at the permitted slope. 5. Catch basins, curb cuts, velocity reduction devices, and piping will be inspected monthly or after every significant runoff producing rainfall event. Trash and debris will be cleared away from grates, curb cuts, velocity reduction devices and piping. G. Swales will not be altered, piped, or filled in without approval from NCDENR Division of Water Quality. 1 acknowledge and agree by my signature below that 1 am responsible for the performance of the six maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Print Name and Title: William "Neal" Lewis. CPRP. Director of New Hanover County Paks Department Address:230 Government Center Drive, Suite 120, Wilmington, North Carolina 28403 Date: 9.1. 69 Signature: Note: The legally responsible park, should 401 � a homeoearecs assuciali0n unless more than 50% of the lots have been sold and a resident n/ the subdivision has been r omed the presideru. 1, 6 "i s 60H6t �"�✓�50�"') , a Notary publictnrr the State of �1 &ID(G tc ileL, County of IJ 0 ✓ew , do hereby certity that Vl dh jr t ,,wa/ personally appeared betorc me this day of t AODg , and acknowledge the due execution of the lixgoing Swale maintenance requirements. Witness my and and of eial seal, fYYW2 0 Notary signature SEAL My conwtission expires Form SW401-1-uw Density-Rev3-2/10/09 Page 4 of 4