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HomeMy WebLinkAboutSW7080107_CURRENT PERMIT_20080610STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. DOC TYPE CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE,�j�(p� YYYYMMDD r r --I Y June 10, 2008 Lake New Bern Development, LLC Attn: Mr. Steve Tyson 820 Broad Street New Bern, NC 28560 Rb Michael F. Easley, Gomor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Coleen H. Sullins Director Division of Water Quality Subject: Permit No. SW7080107 Lake New Bern PUD High Density Stormwater Project Craven County Dear Mr. Tyson: The Washington Regional Office received a complete Stormwater Management Permit Application for the subject project, located off Simmons Street in New Bern, NC on April 16, 2008. Staff review of the plans and specifications has determined that the proJ'ect, as proposed, will comply with the Stormwater Regulations set forth in Title 15A NCAC 2H.MO. We are forwarding Permit No. SW7080107 dated June 10, 2008, for the construction of the subject project. This permit shall be effective from the date of issuance until June 10, 2018, and shall be subject to the conditions and limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit and in the submitted application. Failure to establish an adequate system for operation and maintenance of the stormwater management system will result in future compliance problems. If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be in the form of a written petition, conforming to Chapter 150E of the North Carolina General Statutes, and filed with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this permit shall be final and binding. If you have any questions, or need additional information concerning this matter, please contact either Bill Moore, or me at (252) 946-6481. 4A.HodgeI ncer ly, )�6 �_—_—.__-- Regional Supervisor Surface Water Protection Section cc: Avolis Engineering New Bern Building Inspections ,,-Washington Regional Office Central Files North Carolina Division of Water Quality Internet: h2o.encstate.nc,us 943 Washington Square Mall Phone: 252-946-6481 One Washington, NC 27889 FAX 252-946-9215 NorthCarojjna An Equal Opportunity/Affirmative Action Employer— 50%Recycled110% Post Consumer Paper Naturally STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WATER QUALITY STATE STORMWATER MANAGEMENT PERMIT HIGH DENSITY DEVELOPMENT In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other applicable Laws, Rules, and Regulations PERMISSION IS HEREBY GRANTED TO Lake New Bern Development Company, LLC Lake New Bern PUD Craven County FOR THE construction, operation and maintenance of (2) wet detention basins in compliance with the provisions of 15A NCAC 2H .1000 (hereafter referred to as the "storm water rules') and the approved stormwater management plans and specifications and other supporting data as attached and on file with and approved by the Division of Water Quality and considered a part of this permit. This permit shall be effective from the date of issuance until June 10, 2018, and shall be subject to the following specified conditions and limitations: I. DESIGN STANDARDS This permit is effective only with respect to the nature and volume of stormwater described in the application and other supporting data. This stormwater system has been approved for the management of stormwater runoff as described in Section 1.6 on page 3 of this permit. The stormwater controls have been designed to handle the runoff from 11.42 acres of impervious area. 3. All stormwater collection and treatment systems must be located in either dedicated common areas or recorded easements. The final plats for the project will be recorded showing all such required easements, in accordance with the approved plans and permit. 4. The tract will be limited to the amount of built -upon area indicated on page 3 of this permit, and per approved plans. The runoff from all built -upon area within the permitted drainage areas of this project must be directed into the permitted stormwater control system. Page 2 of 7 A The following design criteria have been provided in the wet detention basins and must be maintained at design condition: a. Drainage Areas: 90.28 ac - Total Site 15.63ac-DA1 15.21 ac-DA2 b. Total Impervious Surfaces: 5.24 ac - DA 1 6.18ac-DA2 C. Design Storm: 1.0 - inch d. Pond Depths: 7.0 - ft e. TSS removal efficiency: 90% f. Permanent Pool Elevations, FMSL: 2.0 - ft g. Permanent Pool Surface Areas: 8,224 sf - DA 1 Required 9,471 sf - DA 2 h. Permanent Pool Surface Areas: 20,253 sf - DA 1 Provided 17,277 sf - DA 2 i. Storage Volumes Required: 29,621 cf - DA 1 31,020 cf - DA 2 k. Temporary Storage Volumes: 29,621 cf - DA 1 Provided 31,020 cf - DA 2 I. Small Diameter Controlling Orifice: 2.50 - inch pipes M. Receiving Stream/River Basin: Rennys Creek n. Classification of Water Body: SC - Sw - NSW II. SCHEDULE OF COMPLIANCE 1. The stormwater management system shall be constructed in its entirety, vegetated and . operational for its intended use prior to the construction of any built -upon surface. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater system functions at optimum efficiency. The approved Operation and Maintenance Plans must be followed in its entirety and maintenance must occur at the scheduled intervals including, but not limited to: a. Semiannual scheduled inspections (every 6 months). b. Sediment removal. C. Mowing and revegetation of slopes and the vegetated filter. d. Immediate repair of eroded areas. e. Maintenance of all slopes in accordance with approved plans and specifications. f. , Debris removal and unclogging of bypass structure, filter media, flow spreader, catch basins, piping and vegetated filter. g. A clear access path to the bypass structure must be available at all times. Page 3 of 7 4. Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ. The records will indicate the date, activity, name of person performing the work and what actions were taken. The facilities shall be constructed as shown on the approved plans. This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this permitted facility, a certification must be received from an appropriate designer for the system installed certifying that the permitted facility has been installed in accordance with this permit, the approved plans and specifications, and other supporting documentation. Any deviations from the approved plans and specifications must be noted on the Certification. A modification may be required for those deviations. 7. If the stormwater system was used as an Erosion Control device, it must be restored to design condition prior to operation as a stormwater treatment device, and prior to occupancy of the facility. 8. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 9. The permittee shall submit to the Director and shall have received approval for revised plans, specifications, and calculations prior to construction, for any modification to the approved plans, including, but not limited to, those listed below: a. Any revision to any item shown on the approved plans, including the stormwater management measures, built -upon area, details, etc. b. Project name change. C. Transfer of ownership. d. Redesign or addition to the approved amount of built -upon area or to the drainage area. e. Further subdivision, acquisition, lease or sale of all or part of the project area. The project area is defined as all property owned by the permittee, for which Sedimentation and Erosion Control Plan approval or a CAMA Major permit was sought. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan. 10. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 11. A copy of the approved plans and specifications shall be maintained on file by the Permittee at all times. 12. The Director may notify the permittee when the permitted site does not meet one or more of the minimum requirements of the permit. Within the time frame specified in the notice, the permittee shall submit a written time schedule to the Director for modifying the site to meet minimum requirements. The permittee shall provide copies of revised plans and certification in writing to the Director that the changes have been made. 13. This permit shall be effective from the date of issuance until June 10, 2018. Application for permit renewal shall be submitted 180 days prior to the expiration date of this permit and must be accompanied by the processing fee. Page 4 of 7 III. GENERAL CONDITIONS This permit is not transferable except after notice to and approval by the Director. In the event of a change of ownership, or a name change, the permittee must submit a formal permit transfer request to the Division of Water Quality, accompanied by a completed name/ownership change form, documentation from the parties involved, and other supporting materials as may be appropriate. The approval of this request will be considered on its merits and may or may not be approved. The permittee is responsible for compliance with all permit conditions until such time as the Division approves the transfer request. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to enforcement action by the Division of Water Quality, in accordance with North Carolina General Statute 143-215.6A to 143-215.6C. 3. The issuance of this permit does not preclude the Penmittee from complying with any and all statutes, rules, regulations, or ordinances, which may be imposed by other government agencies (local, state, and federal) having jurisdiction. 4. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the Permittee shall take immediate corrective action, including those as may be required by this Division, such as the construction of additional or replacement stormwater management systems. 5. The permittee grants DENR Staff permission to enter the property during normal business hours for the purpose of inspecting all components of the permitted stormwater management facility. 6. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit modification, revocation and reissuance or termination does not stay any permit condition. 7. Unless specified elsewhere, permanent seeding requirements for the stormwater control must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning and Design Manual. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. A copy of the approved plans and specifications shall be maintained on file by the Permittee for the life of the project. The permittee shall notify the Division of any name, ownership or mailing address changes within 30 days. Permit issued this the 10 th day of June, 2008. CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION for Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW7080107 Page 5 of 7 Stormwater Permit No. SV 7080107 Lake New Bern PUD, New Bern, NC (2) Wet Pond Systems Craven County Designer's Certification I, , as a duly registered in the State of North Carolina, having been authorized to observe (periodically/ weekly/ full time) the construction of the project, (Project) for (Project Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the project construction such that the construction was observed to be built within substantial compliance and intent of the approved plans and specifications. Note: The checklist on the following page must be included with this Certification. Any changes or deviations from the approved plans and specifications must be explained in detail, and may require a permit modification. The certification forms should be submitted to the Division of Water Quality at the appropriate Regional office. Signature Registration Number Date SEAL Page 6 of 7 Complete this checklist for each system and include with Certification: 1. The drainage area to the system contains approximately the permitted acreage. 2. The drainage area to the system contains no more than the permitted amount of built -upon area. 3. All the built -upon area associated with the project is graded sucha e runoff drains to the system. 4. All roof drains are located such that the runoff is directed into the system. 5. The bypass structure elevations are per the approved plan. 6. The bypass structure is located per the approved plans. 7. A Trash Rack is provided on the outlet/bypass structure. 8. All slopes are grassed with permanent vegetation. 9. Vegetated slopes are no steeper than 3:1. 10. The inlets are located per the approved plans and do not cause short-circuiting of the system. 11. The permitted amounts of surface area and/or volume have been provided. 12. All required design depths are provided. 13. All required parts of the system are provided. 14. The required system dimensions are provided per the approved plans. Page 7 of 7 If tm. 1rr DWQ USE ONLY Date Received Fee Paid Permit Number 2008 DUVQUIl" State of North Carolina SWACK epartment of Environment and Natural Resources I Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM 0' This form may be photocopied for use as an original I. GENERAL INFORMATION 'I. Applicants name (specify the name of the corporation, individual, etc. who owns the project): Lake New Bern Development Company, LLC 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Steve Tyson, Member/Manager 3. Mailing Address for person listed in item 2 above: City:New Bern State:NC Zip:28560 Phone: (252 514-9157 Fax: ( 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Lake New Bern - A Planned Unit Development 5. Location of Project (street address): City: 6. Directions to project (from nearest major intersection): County:Craven South Glenburnie Road to Neuse Boulevard. Turn right onto Neuse Boulevard. Turn left onto Simmons Street. Project is approximately 1.2 miles on left. 7. LatitUde:N 35 7.5' Longitude:W 77 4.2' of project 8. Contact person who can answer questions about the project: Name:Steve Tyson Telephone Number: (252 ) 514-9157 Email: H. PERMIT INFORMATION: 1. Specify whether project is (check one): Form SWU-101 Version 8.07 ®New Page I of 4 ❑Renewal OModification 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing permit number and its issue date (if known) 3. Specify the type of project (check one): ❑Low Density ®Fligh Density ❑Redevelop ❑General Permit ❑Universal SMP ❑Other 4. Additional Project Requirements (check applicable blanks): ❑CAMA Major ®Sedimentation/Erosion Control ❑404/401 permit ❑NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748. Ill. PROJECT INFORMATION 1. In the space provided below, summarize how Stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project . 2. Stormwater runoff from this project drains to the Neuse River basin. 3. Total Site Area: 90.275 acres 4. Total Wetlands Area: 56.0 acres 5. 100' Wide Strip of Wetland Area: 3 acres (not applicable if no wetlands exist on site) 6. Total Project Area**:90.275 acres 7. Project Built Upon Area:13.0 % 8. How many drainage areas does the project have?3 9. Complete the following information for each drainage area. If there are more than two drainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. Basin Information Drainage Area 1 Drainage Area 2 Receiving Stream Name IZenny's Creek Renny's Creek Stream Class & Index No. SC, Sw, NSW SC, Sw, NSW Drainage Area (so 680,784 SF, 15.63 AC 662,339 SF, 15.21 AC Existing Impervious* Area (so 0 0 Proposed Impervious*Area (so 228,409 SF, 5.24 AC 269,083 SF, 6.18 AC `% Impervious* Area (total) 33.55% 40.63% Impervious* Surface Area Drainage Area 1 Drainage Area 2 On -site Buildings (so 142,254 SF 182,898 SF On -site Streets (so 65,250 SF 65,050 SF On -site Parking (so --- --- On-site Sidewalks (so 9,640 SF 9,160 SF Other on -site (so 11,265 SF 11,975 SF Off -site (so Total (so: 228,409 SF, 5.24 SF 269,083 Sf, 6.18 AC * Impervious area is defined as the built upon area including, but not limited to, buildings, rands, parking areas, sidewalks, gravel areas, etc. Form SWU-101 Version 8.07 Page 2 of 4 ,/ 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing permit number and its issue date (if known) 3. Specify the type of project (check one): Low Density _High Density Redevelop General Permit Other 4. Additional Project Requirements (check applicable blanks): CAMA Major _Sedimentation/Erosion Control 404/401 Permit _NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748. III. PROJECT INFORMATION 1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project . 2. Stormwater runoff from this project drains to the 3. Total Project 5. How many drainage areas does the project have? River basin. 4. Project Built Upon Area: % 6. Complete the following information for each drainage area. If there are more than two drainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. Basin Information Drainage Area 3 Drainage Area 2 Receiving Stream Name Renny' s Creek Receiving Stream Class SC, Sw, NSW Drainage Area 2,5B9256 SF 5 AC Existing Impervious* Area 0 Proposed Impervious"Area 14,000 SF 0.32 AC % Impervious* Area (total) 0.5 Impervious" Surface Area Drainage Area 1 Drainage Area 2 On -site Buildings 0 On -site Streets 14, 000 SF On -site Parking _ On -site Sidewalks Other on -site _ Off -site Total: 14,000 SF, 0.32 AC Total: Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 **Total project area shall be calculated based on the current policy regarding inclusion of wetlands in the built upon m"ea percentage calculation. 10. 1-low was the off -site impervious area listed above derived IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS One of the following deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. Form DRPC-1 High Density Commercial Subdivisions Form DRPC-2 High Density Developments with Oulparcels Form DRPC-3 High Density Residential Subdivisions Form DRPC-4 Low Density Commercial Subdivisions Form DRPC-5 Low Density Residential Subdivisions Form DRPC-6 Low Density Residential Subdivisions with Curb Outlets By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the applicable items required in the above form, that the covenants will be binding on all parties and persons claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the sale of any lot. V. SUPPLEMENT FORMS The applicable state stormwater management permit supplement form(s) listed below must be submitted for each BMP specified for this project. Contact the Stormwater and General Permits Unit at (919) 733-5083 for the status and availability of these forms. Form SW401-Low Density Form SW401-Curb Outlet System Form SW40I-Off-Site System Form SW401-Wet Detention Basin Form SW401-Infiltration Basin Form SW401-Infiltration Trench Form SW401-Bioretention Cell Form SW40"I-Level Spreader Form SW40"I-Welland Norm SW401 -G rassed Swale Form SW401-Sand Filler Low Density Supplement Curb Outlet System Supplement Off -Site System Supplement Wet Detention Basin Supplement Infiltration Basin Supplement Underground Infiltration Trench Supplement Bioretention Cell Supplement Level Spreader/Filter Strip/Restored Riparian Buffer Supplement Constructed Welland Supplement Grassed Swale Supplement Sand Filler Supplement Form SWU-101 Version 8.07 Page 3 of 4 VI. SUBMITTAL REQUIREMENTS Only complete application packages will be 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 appropriate DWQ Office. (Appropriate office may be found by locating project on the interactive online map at http://h2o.enr.state.nc.us/su/msi maps.hun Please indicate that you have provided the following required information by initialing in the space provided next to each item. Initials • Original and one copy of the Stormwater Management Permit Application Form • Original and one copy of the Deed Restrictions & Protective Covenants Form • Original of the applicable Supplement Form(s) and O&M agreement(s) for each BMP • Permit application processing fee of $505 ($4,000 for Express) payable to NCDENR • Calculations & detailed narrative description of Stormwater treatment/management • Copy of any applicable soil report • Three copies of plans and specifications (sealed, signed & dated), including: - Development/Project name - Engineer and firm - Legend - North arrow - Scale - Revision number & date - Mean high water line - Dimensioned property/project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Details of roads, drainage features, collection systems, and Stormwater control measures - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VII. AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. Designated agent (individual or firm): Avolis Engineering P.A. Mailing Address: P.O. Box 15564 Phone: (252 ) 633-0068 Email:avoliseng@lpmonline.net VIII. APPLICANT'S CERTIFICATION State:NC Zip:28561 Fax: (252 ) 633-6507 1, (print or type, name of person listed in General Information, item 2) Steve Tyson certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that the required deed restrictions and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A NCAC 21-1 .1000. , _ Signa Date: FormSWU-101 Version8.07 Page 4of4 STORMWATER NARRATIVE Lake New Bern - A Planned Unit Development Simmons Street New Bern, North Carolina The Lake New Bern Subdivision project consists of the development of a 96 lot single-family residential subdivision on 90.275 acre parcel of land located on the western side of Simmons Street on the northern extent of the City of New Bern, Craven County, North Carolina. A public access road will be extended off of Simmons Street and will be extended throughout the property and will connect to Oaks Road as delineated on the project plans. The subject property was the previous location of Renny's Creek Mine. A manmade lake covering a total area of approximately 60 acres remains on the site. The subject property has been divided by grading activities and natural topographic relief into three primary drainage basins. Drainage Basin No. 1 covers a total approximately 15.63 acres and is located adjacent to Simmons Street as presented on the project plans. It is proposed that a total of 5.24 acres of impermeable surfaces be created in Drainage Basin No.I yielding a total built -upon of 33.55%. Stormwater Retention Pond No. 1 will be constructed within Drainage Basin No. I and has been sized for 90% TSS removal. All runoff from Drainage Basin No.1 will be directed to the forebay area of Stormwater Retention Pond No. 1. Stormwater Retention Pond No. 1 will discharge to the large existing manmade lake located on the site. Drainage Basin No. 2 covers a total area of 15.21 acres of land as delineated in the project calculations. It is proposed that a total of 6.18 acres of impermeable surfaces be created within this drainage basin. Stormwater Retention Pond No. 2 will be constructed within this drainage basin. This pond is designed for 90% TSS removal and will discharge to the existing manmade lake on the property. Drainage Basin No. 3 represents that portion of the property primarily covered by the existing manmade lake and small fringe upland areas. Minimum impermeable surfaces are proposed for this drainage basin. Specifically, it is proposed that a total of 14,000 square feet of roadway surfaces be constructed in this basin. Stormwater runoff from this roadway area will be collected and will be directed to the vegetated swale located along Oaks Road. The total built upon for this drainage basin is 0.54%. Considering the site in its entirety, it is proposed that a total of 511,292 square feet, 11.74 acres of impermeable surfaces be created. The overall project built -upon percentage is 13.0%. All Stormwater runoff from the subject property will ultimately discharge to the manmade lake located on the property. One small existing outlet pipe is located on the northern side of this pond and discharges under overflow conditions to the adjacent Renny's Creek. This outlet pipe will not be altered in any manner. This manmade lake will provide additional treatment in nitrogen removal for any runoff exiting the site. The stormwater system proposed for this subdivision complies with the Coastal Stormwater Permitting Regulations and also will provide nitrogen removal and runoff attenuation required to comply with the City of New Bern Stormwater Permitting Program. Permit No. (to be provided by DWq) (A, O� F W A TF9OG NCDENR � STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form must be filled out, printed and submitted. The Required Items Checklist (Part III) must be printed, filled out and submitted along with all of the required information. Project name _- - - Lake New Bern — Contact person Steve Tyson Phone number 252-514-9157 Date January 16,200 Drainage area number 1 DESIGN;INFORMATION,as,tn,gSb•ii,:4PA%;c",,,Ii 'aaw— Site Characteristics 2 /5— 63 &L ° i/ Drainage area 680,784 ft Impervious area 228,409 ft2 %impervious 33.55 % Design rainfall depth 1 in Storage Volume: Non-SRWaters Minimum volume required 29�621 fly Volume provided 2�6�, 2121 ft3 ✓ Storage Volume: SR Waters 1-yr, 24-hr runoff depth — — — in Pre -development 1-yr, 24-hr runoff ft3 Post -development 1-yr, 24-hr runoff — — — rya Minimum volume required — — — ft3 Volume provided — — — ft, Peak Flow Calculations Is pre/post control of the 1-yr 24-hr peak flow required? Y (Y or N) 1-yr, 24-hr rainfall depth 0.5 in Rational C, pre -development 0.3 (unitless) Rational C, post -development 0.526 (unitless) Rainfall intensity: 1-yr, 24-hr storm 'j Whir Pre -development 1-yr, 24-hr peak flow 25 , 5 ft�/sec Post -development 1-yr, 24-hr peak flow 7.57 ft'/sec Pre/Post 1-yr, 24-hr peak flow control 7.57 ft3/sec Basin Elevations Basin bottom elevation —5.0 ft Sediment cleanout elevation —3 , 25 it Bottom of shelf elevation 1 .5 ft Permanent pool elevation 2.0 ft Top of shelf elevation 2.5 It Temporary pool elevation 3.3 it Volume and Surface Area Calculations SAIDA ratio 1.21 (unitless) Surface area at the bottom of shelf , 2� 73 ft' Volume at the bottom of shelf 0 ft3 / Permanent pool, surface area required $ 22 ft2 ✓ Permanent pool, surface area provided 20.2���ft2 Permanent pool volume 81 0025 ft3 Average depth for SAIDA tables 7ft Surface area at the top of shelf 20,253 ft2 Volume at the lop of shelf 81,025 ft3 Form SW401-Wet Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 1 of 2 Permit No. (to be provided by DWq) Forebay volume ft' Forebay % of permanent pool volume 2 Temporary pool, surface area provided 27,186 ft2 ✓ Drawdown Calculations Treatment volume drawdown time 3.25 days Treatment volume discharge rate � 7.�7��� fi'Is Pre -development 1-yr, 24-hr discharge 255.56 efs Post -development 1-yr, 24-hr discharge 7.57 ft'Is Additional Information Diameter of orifice 2,5 in Design TSS removal 90 % Basin side slopes 3 :1 Vegetated shelf slope 10 :1 Vegetated shelf width 10 It Length of flowpath to width ratio 2,6 .1 Length to width ratio 3.7 :1 Trash rack for overflow & orifice? Y (Y or N) Freeboard provided 4.2 ft Vegetated filter provided? N (Y or N) Recorded drainage easement provided? N (Y or N) Capures all runoff at ultimate build -out? Y (Y or N) Drain mechanism for maintenance or emergencies Pump Form SW401-Wet Detention Basin-Rev.a Parts I. & II. Design Summary, Page 2 of 2 Permit (to be provided by DWQ) III:;REQUIRED,ITEMS,CHECKLISTa ` ! `w° fr : M"r,{t 2 wily �w, ii,;aw�4'«9$r 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 the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a requirement has not been met, attach justification. Pagel Plan Initials Sheet No. Cl/4 1. Plans (1" - 50' or larger) of the entire site showing: - Design at ultimate build -out, - Off -site drainage (if applicable), - Delineated drainage basins (include Rational C coefficient per basin), - Basin dimensions, - Pretreatment system, - High flow bypass system, - Maintenance access, - Recorded drainage easement and public right of way (ROW), - Overflow device, and - Boundaries of drainage easement. C10 2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing: - Outlet structure with trash rack or similar, - Maintenance access, - Permanent pool dimensions, - Forebay and main pond with hardened emergency spillway, - Basin cross-section, - Vegetation specification for planting shelf, and - Filter strip. C10 3. Section view of the dry detention basin (1" = 20' or larger) showing: - Side slopes, 3:1 or lower, - Pretreatment and treatment areas, and - Inlet and outlet structures. C4 4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified on the plans prior to use as a wet detention basin. X 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay, to verify volume provided. R 6. An assurance that the installed system will meet design specifications upon initial operation once the project is complete and the entire drainage area is stabilized. 4- C1 7. A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized. X 8. The supporting calculations. X 9. A copy of the signed and notarized inspection and maintenance (AM) agreement. X 10, A copy of the deed restriction. Form SW401-Wet Detention Basin-Rev.1 Part III. Required Items Checklist, Page 1 of 1 Permit Number: (to he provided by Dlt'Q) Drainage Area Number:_ Wet Detention Basin Inspection and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in a known set location. Any deficient BMP elements noted in the inspection will be corrected, repaired or replaced immediately. These deficiencies can affect the integrity of structures, safety of the public, and the removal efficiency of the BMP. The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one): ❑ does ® does not incorporate a vegetated filter at the outlet. This system (check one): ❑ does ® does not incorporate pretreatment other than a forebay. Important maintenance procedures: — Immediately after the wet detention basin is established, the plants on the vegetated shelf and perimeter of the basin should be watered twice weekly if needed, until the plants become established (commonly six weeks). — No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to establish the plants on the vegetated shelf. — Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention basin. — If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain should be minimized to the maximum extent practical. — Once a year, a dam safety expert should inspect the embankment. After the wet detention pond is established, it should be inspected once a month and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of inspection and maintenance should be kept in a known set location and must be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potentialproblem: How I will remediate theproblem: The entire BMP Trash/debris is present. Remove the trash/debris. The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to detention basin erosive gullies have formed. remove the gully, and then plant a ground cover and water until it is established. Provide lime and a one-time fertilizer application. Vegetation is too short or too Maintain vegetation at a height of long. approximately six inches. Form SW401-Wet Detention Basin I&M-Rev.? Permit Number: (to he provided by DWQ) Drainage Area Number: 1 BMP element: Potentialproblem: How I will remediate theproblem: The inlet device: pipe or The pipe is clogged. Unclog the pipe. Dispose of the swale sediment off -site. "the pipe is cracked or Replace the pipe. otherwise damaged. Erosion is occurring in the Regrade the Swale if necessary to swale. smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. The forebay Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design depth for possible. Remove the sediment and sediment storage. dispose of it in a location where it will not cause impacts to streams or the BMP. Erosion has occurred. Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. The vegetated shelf Best professional practices Prune according to best professional show that pruning is needed practices to maintain optimal plant health. Plants are dead, diseased or Determine the source of the dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-time fertilizer application to establish the ground cover if a soil test indicates it is necessary. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. The main treatment area Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design sediment possible. Remove the sediment and storage depth. dispose of it in a location where it will not cause impacts to streams or the BMP. Algal growth covers over Consult a professional to remove 50% of the area. and control the algal growth. Cattails, phragmites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (do not spray). the basin surface. Form SW401-Wet Detention Basin I&M-Rev.? Permit Number: (to be provided btu DMQ) Drainage Area Number: I BMP element: Potentialproblem: How I will remediate theproblem: The embankment Shrubs have started to grow Remove shrubs immediately. on the embankment. Evidence of muskrat or Use traps to remove muskrats and beaver activity is present. consult a professional to remove beavers. A tree has started to grow on Consult a dam safety specialist to the embankment. remove the tree. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. The outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device is damaged Repair or replace the outlet device. The receiving water Erosion or other signs of Contact the local NC Division of damage have occurred at the Water Quality Regional Office, or outlet. the 401 Oversight Unit at 919-733- 1786. The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 5.25 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 5.25 feet in the forebay, the sediment shall be removed. Sediment Removal Bottom BASIN DIAGRAM (/ill in the blanks) Permanent Pool Elevation 2.0 —3 25 l Pe manen Pool ------------------ VOlume Sediment Removal Elevation —3.25 —5.0 ft Min. -- - - ---------. Sediment Bottom Elevation —5.0 Storage FOREBAY MAIN POND ------- 1-fl Mai Storage Form SW401-Wet Detention Basin 1&M-Rev.2 Permit Number: (to he provided by DWQ) 1 acknowledge and agree by my signature below that I am responsible for the performance of the 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. Project mane: Lake New Bern — A Planned Unit Development BMP drainage area number: Print Title: Member/Manager Address: 820 Broad Street. New Bern. NC 28560 Note: The legally 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. 1, Beth Simmons a Notary Public for the State of North Carolina , County of Craven , do hereby certify that Steve Tyson personally appeared before me this `lJ , day of-.) 20 , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, SI M4f Nisi NOTARY y PUBLIC k� ��9aC) � ij14i VeNltCp"\`xx SEAL My commission expires April 22. 2009 Form SW40I-Wet Detention Basin I&M-Rev.2 Permit (to be Provided by DWq) e NCDENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form must be filled out, printed and submitted. The Required Items Checklist (Part III) must be printed, filled out and submitted along with all of the required information. Project name Contact person Phone number Date Drainage area number W A TF, o�OF v � r o ILiDESIGNffNFORMATIONf Site Characteristics Drainage area 662 ft2 /S;Zf as Impervious area 269,083 ry' 6. 8 %impervious 40.63 % r/ Design rainfall depth 1 in Storage Volume: Non-SRWaters / Minimum volume required 319020 ft3 t/ Volume provided 312020 ft3 Storage Volume: SR Waters 1-yr, 24-hr runoff depth --- in Pre -development 1-yr, 24-hr runoff --- ft3 Post -development 1-yr, 24-hr runoff — — — ft3 Minimum volume required --- ft3 Volume provided ft3 Peak Flow Calculations Is pre/post control of the 1-yr 24-hr peak Flow required? Y (Y or N) 1-yr, 24-hr rainfall depth 0.5 in Rational C, pre -development �0, (unitless) Rational C, post -development 0.562 (unitless) Rainfall intensity: 1 -yr, 24-hr storm 3,7 inlhr Pre -development 1-yr, 24-hr peak Flow 24.87 ft3lsec Post -development 1-yr, 24-hr peak flow 8.70 ft3lsec Pre/Post 1-yr, 24-hr peak flow control —B -7�— ft3/sec Basin Elevations / Basin bottom elevation —5.0 It ✓ Sediment cleanout elevation —3.25 It Bottom of shelf elevation 1 .7—ft / Permanent pool elevation 2.0 It V Top of shelf elevation Temporary 2.5 It pool elevation 3.6 It Volume and Surface Area Calculations SAIDA ratio 1.43 (unitless) Surface area at the bottom of shelf ,Z _7$G___ ft2 Volume at the bottom of shelf 0 ft3 Permanent pool, surface area required 9,1, 71 ft2 ✓ Permanent pool, surface area provided 17 277 fit" —, Permanent pool volume 75,989 ft3 Average depth for SAIDA tables 7 fit Surface area at the top of shelf 17,277 ft2 Volume at the top of shelf 75,989 ft3 Form SW401-Wet Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 1 of 2 Permit (to be provided by DWD) Forebay volume zj , IOU It, Forebay % of permanent pool volume 33.1 % Temporary pool, surface area provided 22,801 ft' Drawdown Calculations Treatment volume drawdown time 3.5 days Treatment volume discharge rate 8.70 ft'IS Pre -development 1-yr, 24-hr discharge 24.87 ft'Is Post -development 1-yr, 24-hr discharge 8.70 ft3Is / Additional Information Diameter of orifice 2, 5 in '✓// Design TSS removal 90 % ✓ Basin side slopes 3 :1 Vegetated shelf slope 10 :1 Vegetated shelf width 10 ft Length of flowpath to width ratio 3.2 :1 Length to width ratio 3.2 :1 Trash rack for overflow & orifice? y (Y or N) Freeboard provided 5.4 ft Vegetated filter provided? N (Y or N) Recorded drainage easement provided? N (Y or N) Capures all runoff at ultimate build -out? Y (Y or N) Drain mechanism for maintenance or emergencies mu�p Form SW401-Wet Detention Basin-Rev.3 Parts I. & 11. Design Summary, Page 2 of 2 Permit (to be provided by DWQ) III:REQUIRED;ITEMSICHECKLIST,.s'w"a�h,�„ r�",�;'''±•,;+"��''�k'i%s`s`'��,�s�€k��.`t',�s%:�' ��vf�S�a 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 the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a requirement has not been met, attach justification. Pagel Plan Initials Sheet No. C1 / 4 1. Plans (1" - 50' or larger) of the entire site shovWng: - Design at ultimate build -out, - Off -site drainage (if applicable), - Delineated drainage basins (include Rational C coefficient per basin), - Basin dimensions, - Pretreatment system, - High flow bypass system, - Maintenance access, - Recorded drainage easement and public right of way (ROW), - Overflow device, and - Boundaries of drainage easement. C10 2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing: - Outlet structure with trash rack or similar, - Maintenance access, - Permanent pool dimensions, - Forebay and main pond with hardened emergency spillway, - Basin cross-section, - Vegetation specification for planting shelf, and - Filter strip. C10 3. Section view of the dry detention basin (1" = 20' or larger) showing: - Side slopes, 3:1 or lower, - Pretreatment and treatment areas, and - Inlet and outlet structures. -�- C4 4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified on the plans prior to use as a wet detention basin. X 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay, to verify volume provided. % 6. An assurance that the installed system will meet design specifications upon initial operation once the project is complete and the entire drainage area is stabilized. C1 7. A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized. x__— 8. The supporting calculations. /1 % 9. A the inspection copy of signed and notarized and maintenance (I&M) agreement. X 10. A copy of the deed restriction. Form SW401-Wet Detention Basin-Rev.1 Part III. Required Items Checklist, Page 1 of 1 Permit Number: (to be provided by DWQ) Drainage Area Number: 2 Wet Detention Basin Inspection and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in a known set location. Any deficient BMP elements noted in the inspection will be corrected, repaired or replaced immediately. These deficiencies can affect the integrity of structures, safety of the public, and the removal efficiency of the BMP. The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one): ❑ does ❑ does not incorporate a vegetated filter at the outlet. This system (check one): ❑ does ® does not incorporate pretreatment other than a forebay. Important maintenance procedures: — Immediately after the wet detention basin is established, the plants on the vegetated shelf and perimeter of the basin should be watered twice weekly if needed, until the plants become established (commonly six weeks). — No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to establish the plants on the vegetated shelf. — Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention basin. — If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain should be minimized to the maximum extent practical. — Once a year, a dam safety expert should inspect the embankment. After the wet detention pond is established, it should be inspected once a month and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of inspection and maintenance should be kept in a known set location and must be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potentialproblem: How 1 will remediate theproblem: The entire BMP Trash/debris is present. Remove the trash/debris. The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to detention basin erosive gullies have formed. remove the gully, and then plant a ground cover and water until it is established. Provide lime and a one-time fertilizer application. Vegetation is too short or too Maintain vegetation at a height of long. approximately six inches. Form SW401-Wet Detention Basin IRM-Rev.2 Permit Number: (to be provided by DWQ) Drainage Area Number: 2 BMP element: Potentialproblem: How 1 will remediate theproblem: The inlet device: pipe or The pipe is clogged. Unclog the pipe. Dispose of the Swale sediment off -site. The pipe is cracked or Replace the pipe. otherwise damaged. Erosion is occurring in the Regrade the swale if necessary to Swale. smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. The forebay Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design depth for possible. Remove the sediment and sediment storage. dispose of it in a location where it will not cause impacts to streams or the BMP. Erosion has occurred. Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. The vegetated shelf Best professional practices Prune according to best professional show that pruning is needed practices to maintain optimal plant health. Plants are dead, diseased or Determine the source of the dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-time fertilizer application to establish the ground cover if a soil test indicates it is necessary. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. The main treatment area Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design sediment possible. Remove the sediment and storage depth. dispose of it in a location where it will not cause impacts to streams or the BMP. Algal growth covers over Consult a professional to remove 50% of the area. and control the algal growth. Cattails, phragmites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (do not spray). the basin surface. Form SW401-Wet Detention Basin I&M-Rev.2 Permit Number: (to be provided by D 111Q) Drainage Area Number 2 BMP element: Potentialproblem: How I will remediate theproblem: The embankment Shrubs have started to grow Remove shrubs immediately. on the embankment. Evidence of muskrat or Use traps to remove muskrats and beaver activity is present. consult a professional to remove beavers. A tree has started to grow on Consult a dam safety specialist to the embankment. remove the tree. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. The outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device is damaged Repair or replace the outlet device. The receiving water Erosion or other signs of Contact the local NC Division of damage have occurred at the Water Quality Regional Office, or outlet. the 401 Oversight Unit at 919-733- 1786. The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 5.25 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 5.25 feet in the forebay, the sediment shall be removed. Sediment Removal Bottom BASIN DIAGRAM (fill in the blanks) Permanent Pool Elevation 2.0 —325 Pe manen Pool -------------- ---- Volume Sediment Removal Elevation —3.25 —5.0 -ft Min. Sediment Bottom Elevation-5.0 Storage FOREBAY MAIN POND 1-ft Storage Form SW401-Wet Detention Basin 1$M-Rev.2 Permit Number: (to he provided by UWQ) acknowledge and agree by my signature below that I am responsible for the performance of the 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. Prgject name: Lake New Bern — A Planned Unit Development BMP drainage area number: Print Title: Member/Manager Address: 820 Broad Street, New Bern, NC 28560 Note: The legally 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. 1, Beth Simmons , a Notary Public for the State of North Carolina . County of Craven , do hereby certify that Steve Tyson personally appeared before me this l, l, 0 hday of 'Z Gd , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, SI NOTARY PUBLIC �--� 'tttnnnntt"� SEAL My commission expires April 22, 2009 Form SW401-Wet Detention Basin I&M-Rev.2