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HomeMy WebLinkAbout20041466 Ver 2_Stormwater Info_20150819ColeJenest & Stone f r Land Planning Landscape Architecture Civil Engineering Urban Design 200 South Tryon Street, Suite 1400 Charlotte, NC 28202 P+ 704 376 1555 f+ 704 376 7851 url +www.colejeneststone.com Date: Reference: Attention: Company: We Are Transmitting: U August 18, 2015 Charlotte Raleigh TRANSMITTAL 4323.05 — Chesapeake Pointe Revised Construction Documents Ms. Karen Higgins North Carolina Department of Environment Tel: 919- 807 -6300 and - Natural Resources Division of Water Resources 512 North Salisbury Street Raleigh, North Carolina 27604 ® Herewith ❑ Under Separate Cover Copies Dated Description 1 08/12/15 Low Density Supplement Application 1 07/02/15 Construction Drawings (CV1.0, CV3.0, CV3.1, CV3.2, CV4.0, CV4.1, CV4.2, CV5.3, CV5.4, CV5.5, CV7.3) Transmitted ❑ Mail ® Overnight ❑ Courier ❑ Hand Delivery ❑ Pick -Up Via: ❑ For Approval ❑ For Your Use ® As Requested ❑ For Review Remarks: The attached documents are being submitted pursuant to the conditions of the 401 Water Quality Certification issued under DWR #04- 1466V2, dated July 9, 2015, and per telephone discussion with Mr. Boyd Devane on August 7, 2015. Please contact our office with any additional questions or comments. Thank you. By: R. Todd Fisher, PE sac cc: Mr. Alec Rickenbaker — Peachtree Residential P 1SDSKPROJM323% Correspondencest2015 %Trans\0818t Higgins, K - NCDENR DWR docx V ColeJenest & Stone f r Land Planning Landscape Architecture Civil Engineering Urban Design 200 South Tryon Street, Suite 1400 Charlotte, NC 28202 P+ 704 376 1555 f+ 704 376 7851 url +www.colejeneststone.com Date: Reference: Attention: Company: We Are Transmitting: U August 18, 2015 Charlotte Raleigh TRANSMITTAL 4323.05 — Chesapeake Pointe Revised Construction Documents Ms. Karen Higgins North Carolina Department of Environment Tel: 919- 807 -6300 and - Natural Resources Division of Water Resources 512 North Salisbury Street Raleigh, North Carolina 27604 ® Herewith ❑ Under Separate Cover Copies Dated Description 1 08/12/15 Low Density Supplement Application 1 07/02/15 Construction Drawings (CV1.0, CV3.0, CV3.1, CV3.2, CV4.0, CV4.1, CV4.2, CV5.3, CV5.4, CV5.5, CV7.3) Transmitted ❑ Mail ® Overnight ❑ Courier ❑ Hand Delivery ❑ Pick -Up Via: ❑ For Approval ❑ For Your Use ® As Requested ❑ For Review Remarks: The attached documents are being submitted pursuant to the conditions of the 401 Water Quality Certification issued under DWR #04- 1466V2, dated July 9, 2015, and per telephone discussion with Mr. Boyd Devane on August 7, 2015. Please contact our office with any additional questions or comments. Thank you. By: R. Todd Fisher, PE sac cc: Mr. Alec Rickenbaker — Peachtree Residential P 1SDSKPROJM323% Correspondencest2015 %Trans\0818t Higgins, K - NCDENR DWR docx Permit No. (to be provided by DEMLR) State of North Carolina Department of Environment and Natural Resources Division of Energy, Mineral and Land Resources 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 214 .1002(18). Low density requirements and density factors can be found in Session Law 2008 -211, 15A NCAC 2H .1000, Session Law 20`16_246 and the State of North Carolina Stormwater Best Management Practice Manual. Curb and gutter systet -they meet the requirements in 15A NCAC 2H .1008(g). - -- _— f L I. PROJECT INFORMATION A 11 r 1 A 7 015 Pro ect Name : Chesapeake Pointe -Leeward Shoal Lane DENF J _ 401 & ourrtK F t Contact Person: Todd Fisher Phone Number: ( 704 )971 Number of Lots:4 (Lots 17.18.19.20) Allowable Built Upon Area (BUA) Per Lot *:23.974 SF Number of Dwelling Units Per Acre* *:0.39 DU /ac 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 H Post- Construction [non -SA] only) II. BUILT UPON AREA Refer to DEMLR's forms and applications website for specific language that must be recorded in the deed restrictions for all subdivided projects. (httn:Ht)ortal.ncdenr.org /web/Ir /state- stonnwater -forms docs) Complete the following calculation in the space provided below where: • SA Site Area - the total project area above Mean High Water. • 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 1 of 4 Calculation: For uniform lot sizes: (SA: 449975 ft2 x DF: 0.24) - (RA: 12097 ft2) - (OA: 0 ft2) = BUA per Lot = 23974 ft2 (No of Lots: 4) For non - uniform lot sizes: a. (SA: ft2 x DF: ) - (RA b. Total BUA from lot listing: sf III. DESIGN INFORMATION ft2) - (OA: ft2) = Total allowable lot BUA = b must be <- a ft2 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.noaa.gov/hdsc /pfds/ Table 1. Swale design information based on the 10 -year storm. Swale No. Drainage Impervious Grassed C Q Slope 0.45 Area (ac) Area (ac) Area (ac) 0.25 (cfs) M 1 1.23 0.36 0.87 0.49 4.4 0.16 2 0.21 0.05 0.16 0.45 0.7 0.16 3 1.60 0.33 1.27 0.43 5.0 0.14 4 0.53 0.08 0.45 0.40 1.5 0.14 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 V., ". Flow (fps) (fps) Depth (ft) 12.5 4.57 0.45 12.5 1.73 0.25 13.2 4.59 0.49 13.2 2.51 0.33 . IV. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the -North'Carolina Administrative Code Section 15A NCAC 211 .1000, NCDENR BMP Manual (2007), Session Law 2006 -246, and Session Law 2008 -211. 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 anv item is not met. then iustification must be attached. Only complete items n through p for projects with curb outlets. Page/Plan Initials Sheet No. N/A a. t For projects in the 20 coastal counties: Per NCAC 2H.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. t For HQW or ORW projects outside the 20 coastal counties: A 30 foot wide vegetative buffer is provided adjacent to surface waters. CV4.0 c.' For.Phase II Post - Construction projects: All built upon area is located at least 30 feet landward of all perennial and intermittent surface waters. (50' buffer provided) 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. above 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 2H.1007) CV7.3 g. Side slopes of swales are no steeper than 3:1; or no steeper than 5:1 for curb outlet swales. (2:1 one side) CV4.0 h. 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 %. (calculations attached) CV4.0 i. At a minimum, swales are designed to carry the 10 year storm velocity at a non - erosive rate. N/A 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). CV7.3 k. Swale detail and permanent vegetation is specified on the plans. _ CV7.3 1. - Swale detail provided on plans; includes grass 'type(s) for permanent vegetative cover. CV7.3 m. Swales are located in recorded drainage easements. (overall access & -utility esmt) CV4.0 n.tt Length of swale or vegetated area is at least 100 feet for each curb outlet. CV5.3 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). CV4.0 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 buffers. tt Only complete these items for projects with curb outlets. Form SW401 -Low Density- Rev.3- 2/10/09 Page 3 of 4 . V. SWALE SYSTEM MAINTENANCE REQUIREMENTS 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. 6. Swales will not be altered, piped, or filled in without approval from NCDENR Division of Energy, Mineral and Land Resources. I acknowledge and agree by my signature below that I am responsible for the performance of the six maintenance procedures listed above. I agree to notify DEMLR of any problems with the system or prior to any changes to the system or responsible party. Print Name and Title:Alec Rickenbaker Address:CP Il. LLC. 7380 McGinnis Ferry Road. Suwanee. GA 30024 Phone: 770- 622 -2/22 Date: Signature: Note: The 2gally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. I, PO_Lf� W S Lo_�r , d a Notary Public for the State of 6 L.0 CaJ , County of C; w, rr c bL , do hereby certify that A l 2C Ie�' �-Ke v� hc��C e Y personally appeared before me this 121714 day of A vjLs L I a -2-015 , and acknowledge the due execution of the forgoing swale maintenance requirements. Witness my hand and official seal, P—). � Ld_ J Notary signaE��innyp��, RES GEORGIA F&.A 2018 My commission expireA R i Q LF, JO/9 Form SW401 -Low Density- Rev.3- 2/10/09 Page 4 of 4 81012015 P46 Discharge Peak Flow Period Channel Slope Channel Bottom Width Left Side Slope Right Side Slope Low Flow Liner Retardance Class Vegtation Type Vegetation Density Soil Type NORTH AMERICAN GREEN 4.4 0.25 0.16 1 2 3 D Mix (Sod & Bunch) Fair 50 -75% Clay Loam www.ecmds.com/prinUanalysisf734lOf73412 Erosion Control Materials Design Software Version 5.0 Project Name: Chesapeake Pointe Project Number: 73410 Channel Name: Leeward Shoal 1 Tensar International Corporation 5401 St. Wendel - Cynthiana Road Poseyville, Indiana 47633 Tel. 800.772.2040 Fax 812.867.0247 www.nagreen.com C350 - Class D - Mix (Sod & Bunch) - Fair 50 -75% Phase Reach Discharge Velocity Normal Depth Mannings N Permissible Shear Stress'Calculated Shear Stres6afety Factor Remarks Staple Pattern C350 Unvegetated Straight 4.4 cfs 5.72 ft/s 0.39 ft C350 Reinforced VegetationStraight 4.4 cfs 4.57 ft/s 0.45 ft Underlvina Substrate Straight 4.4 cfs 4.57 ft/s 0.45 ft 0.041 3.2lbs /ft2 3.89lbs /ft2 0.82 UNSTABLE E 0.056 11lbs /ft2 4.51lbs /ft2 2.44 STABLE E -- 1.2lbs /ft2 0.9821bs /ft2 1.22 STABLE -- http: //www.ecmds .com /pririVanalysisf734lQr73412 1/1 8/10/2015 t. I- ,r. uu lost Discharge Peak Flow Period Channel Slope Channel Bottom Width Left Side Slope Right Side Slope Low Flow Liner Retardance Class Vegtation Type Vegetation Density Soil Type NORTH AMERICAN GREENQD 0.7 025 0.16 1 3 2 0 Mix (Sod & Bunch) Fair 50 -75% Clay Loam www.ecmds.com/print/analysisf734lQr73427 Erosion Control Materials Design Software Version 5.0 Project Name: Chesapeake Pointe Project Number: 73410 Channel Name: Leeward Shoal 2 Tensar International Corporation 5401 St Wendel - Cynthiana Road Poseyville, Indiana 47633 Tel. 800.772.2040 Fax 812.867.0247 www.nagreen.com C350 - Class D - Mix (Sod & Bunch) - Fair 50 -75% Phase Reach Discharge Velocity Normal DepthlMannings N Permissible Shear StressoCalculated Shear StresseSafety Factor Remarks Staple Pattern C350 Unvegetated Straight 0.7 cfs 3.4 ft/s 0.15 ft C350 Reinforced Vegetation.Straidt 0.7 cfs 1.73 ft/s 0.25 ft Underlvina Substrate Straight 0.7 cfs 173 ft/s 0.25 ft 0.041 3.2lbs /ft2 1.49lbs /ft2 2.14 STABLE E 0.107 11lbs /ft2 2.49lbs /ft2 4.41 STABLE E -- 1.2lbs /ft2 0.147lbs /ft2 8.16 STABLE -- httpJ/www.ecmds .com /prinVanalysisf73410/73427 1/1 8/10/2015 Tensar Discharge Peak Flow Period Channel Slope Channel Bottom Width Left Side Slope Right Side Slope Low Flow Liner Retardance Class Vegtation Type Vegetation Density Soil Type NORTH AMERICAN GREEN 5 0.25 0.14 1 3 2 D Mix (Sod & Bunch) Fair 50 -75% Clay Loam www.ecmds.com/printlanalysisf734lOf73429 Erosion Control Materials Design Software Version 5.0 Project Name: Chesapeake Pointe Project Number: 73410 Channel Name: Leeward Shoal 3 Tensar International Corporation 5401 St Wendel - Cynthiana Road Poseyville, Indiana 47633 Tel. 800.772.2040 Fax 812.867.0247 www.nagreen com C350 - Class D - Mix (Sod & Bunch) - Fair 50 -75% Phase Reach Discharge Velocity Normal Depth Mannings N Permissible Shear Stres4Calculatecl Shear Stress!Safety Factor Remarks Staple Pattern C350 Unvegetated Straight 5 cfs 5.64 ft/s 0 43 ft C350 Reinforced Vegetation, Straight 5 cfs 4.59 ft/s 0 49 ft Underlving Substrate Straight 5 cfs 4.59 ft/s 0 49 ft 0.041 3.21bs /ft2 3.74lbs /ft2 0.85 UNSTABLE E 0.054 11lbs /ft2 4.28lbs /ft2 2.57 STABLE E -- 1.2lbs /ft2 0.979lbs /ft2 1.23 STABLE -- http: //www.ecmds .com /printlanalysis[73410f73429 1/1 8/10/2015 iLQ r fin. 1 Discharge Peak Flow Period Channel Slope Channel Bottom Width Left Side Slope Right Side Slope Low Flow Liner Retardance Class Vegtation Type Vegetation Density Soil Type NORTH AMERICAN GREEN 1.5 0.25 0.14 1 3 2 D Mix (Sod & Bunch) Fair 50 -75% Clay Loain www.ecmds.com/printlanalysisf734lOr73430 Erosion Control Materials Design Software Version 5.0 Project Name: Chesapeake Pointe Project Number: 73410 Channel Name: Leeward Shoal 4 Tensar International Corporation 5401 St Wendel - Cynthiana Road Poseyville, Indiana 47633 Tel. 800.772 2040 Fax 812.867.0247 www.nagreen.com C350 - Class D - Mix (Sod & Bunch) - Fair 50 -75% Phase Reach Discharge Velocity Normal Depth Mannings N Permissible Shear Stress Calculated Shear Stress!Safety Factor Remarks Staple Pattern C350 Unvegetated Straight 1.5 cfs 4.06 ft/s 0.23 ft C350 Reinforced Vegetation Straight 1.5 cfs 2.51 ft/s 0.33 ft Underlying Substrate Straight 1 5 cfs 2.51 ft/s 0.33 ft 0.041 3.2lbs /ft2 2.04lbs /ft2 1.57 STABLE E 0.08 11 1bs /ft2 2.871bs /ft2 3 83 STABLE E -- 1.2lbs /ft2 0.304lbs /ft2 3.95 STABLE -- http: //www.ecmds. com /prirTYanalysisf73410f73430 1/1