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HomeMy WebLinkAboutSW8051018_CURRENT PERMIT_20200710STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 D 5 DOC TYPE CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE Zoe b o7l D YYYYMMDD ROY COOPER Governor MICHAEL S. REGAN Secretary BRIAN WRENN Director July 10, 2020 NORTH CAROLINA Environmental Quality United States Marine Corps Camp Lejeune Attn: Mr. Neal Paul 1005 Michael Road Camp Lejeune, NC 28547 Subject: Permit Renewal State Stormwater Management Permit No. SW8 051018 Tarawa Terrace Il Onslow County Dear Mr. Paul: The Wilmington Regional Office received a complete 8 year Stormwater Management Permit Renewal Application for the subject project on June 2, 2020. The Division is hereby notifying you that permit SW8 060137 has been renewed on July 10, 2020, and shall be effective until December 13, 2027. For your records, please find enclosed a renewed, updated, and re -issued permit and a copy of the renewal application. Please keep this permit on file at all times. Please note that the renewed, updated, and re -issued permit does not impose new or different terms; it merely restates some of the previous terms to provide you with a better understanding of your obligations under the permit. The renewal and reissuance of this stormwater permit does not imply that the site is currently in compliance with the terms and conditions of this state stormwater permit. The plans originally approved on December 13, 2005 and most recently revised on October 17, 2008, will remain in full force and effect in accordance with the regulations set forth in Title 15A NCAC 2H.1000. This permit is subject to the conditions and limitations as specified therein. Please pay special attention to the conditions listed in this permit regarding the Operation and Maintenance of the BMP(s), recordation of deed restrictions, procedures for changes of ownership, transferring the permit, and renewing the permit. Failure to establish an adequate system for operation and maintenance of the stormwater management system, to record deed restrictions, to transfer the permit, or to renew the permit, 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 by filing a written petition with the Office of Administrative Hearings (OAH). The written petition must conform to Chapter 150B of the North Carolina General Statutes, and must be filed with the OAH within thirty (30) days of receipt of this permit. You should contact the OAH with all questions regarding the filing fee (if a filing fee is required) and/or the details of the filing process at 6714 Mail Service Center, Raleigh, NC 27699-6714, or via telephone at 919-431-3000, or visit their website at www.NCOAH.com. Unless such demands are made this permit shall be final and binding. If you have any questions, need additional copies of the permit or approved plans, please contact Daniel Sams in the Wilmington Regional Office, at (910) 796-7215 or dan.sams@ncdenr.gov. Sincerely, �J Brian or Wrenn, Direc Division of Energy, Mineral and Land Resources Enclosures: Attachment C — Permitting history Renewal Application Documents DES/dan:111Storr.7waterlPermits & Proiects120201051018 HD12020 07 permit 051018 cc: Wilmington Regional Office Stormwater File D �� North Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources Wilmington Regional Office 1 127 Cardinal Drive Extension I Wilmington, North Carolina 28405 NOIiTN GROUNA � 910,796.7215 State Stormwater Management Systems Permit No. SW8 051018 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENTAL QUALITY DIVISION OF ENERGY, MINERAL AND LAND RESOURCES 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 United States Marine Corps Tawara Terrace 11 Tarawa Blvd, Camp Lejeune, Onlsow County FOR THE construction, operation and maintenance of five wet detention ponds in compliance with the provisions of 15A NCAC 2H .1000 and Session Law 2006-246, as applicable (hereafter referred to as the "stormwater 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 Energy, Mineral and Land Resources and considered a part of this permit. This permit shall be effective from the date of issuance until December 13, 2027, 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. 2. This stormwater system has been approved for the management of stormwater runoff as described in Section 1.7 of this permit. The stormwater control systems have been designed to handle the runoff from a total of 3,565,824 square feet of impervious area. 3. The tract will be limited to the amount of built -upon area indicated in Section 1.7 on page 3 of this permit, and per approved plans. There is no allotment for future built -upon area at the site. 4. 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. 5. The runoff from all built -upon area within the permitted drainage area of this project must be directed into the permitted stormwater control system. Page 1 of 4 State Stormwater Management Systems Permit No. SW8 051018 6. The built -upon areas associated with Phases 5 and 6 of this project shall be located at least 30 feet landward of all perennial and intermittent surface waters. 7. The following design criteria have been provided in the wet detention ponds and must be maintained at design condition: Design Criteria Tarawa Boy Scout Phase 5 Phase 5 Phase 6 Blvd.. Camp Rd. North South Pond Pond Pond Pond Pond a. Drainage Area, acres: 80.85 37.6 28.4 14.93 39.4 Onsite, ft2: 3,018,795 1,637,709 1,237,104 650,351 1,716,264 Offsite, ftz: 503,031 None None None None b. Total Impervious Surfaces, ftz: 1,473,105 687,063 514,008 246,560 645,088 Onsite Buildings, ft2: 439,900 304,350 273,240 34,774 373,660 Onsite Streets, ft2: 297,390 193,082 188,014 35,263 203,244 Onsite Parking/Driveways, ftz: 150,660 101,420 2,280 None 10,500 Onsite Sidewalks, ft2: 68,168 44,600 50,474 3,103 57,684 Other Onsite, ft2: 13,956 43,611 None 173,420 None Offsite, ftz: 503,031 None None None None c. Pond Depth, ft: 5.4 5.0 5.25 5.25 5.62 (average design depth, ft 3.7 3.4 4.0 d. TSS removal efficiency: 90 90 90 90 90 e. Design Storm, inches: 1.0 1.0 1.5 1.5 1.5 f. Permanent Pool Elevation, FMSL: 11 A 9.5 13.0 18.0 15.0 g. Permanent Pool Surface Area, ft2: 130,181 51,831 48,251 341491 66,137 h. Permitted Storage Volume, ft3: 159,439 58,690 66,245 39,582 86,206 i. Tem ors Storage Elevation, FMSL: 12.6 10.54 14.24 19.0 16.14 j. Predevelopment 1-yr 24-hr nla nla 20.56 27.22 28.37 discharge rate, ft31s: k. Controlling Orifice, "O: 6.0 4.0 3.5 2.5 4 I. Post development treatment volume nla nla 0.26 0.12 0,32 discharge rate, ft31s: m. Permanent Pool Volume, ft3: 555,343 158,557 179,024 118,266 265,091 n. Permitted Forebay Volume, ft3: 121,175 38,442 38,364 22,573 53,821 o. Max. Fountain Horsepower, HP: 2 112 314 113 1 p. Receiving StreamlRiver Basin: Northeast Creek 1 White Oak q. Stream Index Number: 19-16- 3.5 r. Classification of Water Body: SC HQW NSW II. SCHEDULE OF COMPLIANCE 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 Plan 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. Page 2 of 4 State Stormwater Management Systems Permit No. SW8 051018 f. Debris removal and unclogging of outlet structure, orifice device, flow spreader, catch basins and piping. g. Access to the outlet structure must be available at all times. 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. 5. Decorative spray fountains will not be allowed in the stormwater treatment system, as the permanent pool volume is less than 30,000 cubic feet. 6. The facilities shall be constructed, operated and maintained in accordance with the provisions of this permit, the approved plans and specifications, and the supporting documents attached to this permit and on file with the Division. 7. 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. 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. 9. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 10. 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. 11. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 12. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of ten years from the date of the completion of construction. 13. 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. Page 3 of 4 State Stormwater Management Systems Permit No. SW8 051018 III. GENERAL CONDITIONS This permit is not transferable to any person or entity except after notice to and approval by the Director. The permittee shall submit a completed and signed "Permit Transfer Application Form" (available on the Division website) accompanied by the required fee and supporting documentation as listed on the form, to the Division at least 60 days prior to any one or more of the following events: a. The sale or conveyance of the project area in whole or in part, except in the case of an individual lot sale that is made subject to the recorded deed restrictions and protective covenants; b. Dissolution of the partnership, corporate, or LLC entity, subject to NCGS 55- 14-05 or NCGS 57D-6-07 and 08; c. Bankruptcy; d. Foreclosure, subject to the requirements of Session Law 2013-121. 2. Any individual or entity found to be in noncompliance with the provisions of this stormwater management permit or the requirements of the Stormwater rules is subject to enforcement procedures as set forth in NCGS 143 Article 21. 3. The issuance of this permit does not preclude the Permittee 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 DEQ 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 issued shall continue in force and effect until the permittee files a request with the Division for a permit modification, transfer, renewal, or rescission; however, these actions do 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. 8. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 9. A permit renewal request must be submitted at least 180 days prior to the expiration date of this permit. The renewal request must include the appropriate application, documentation and the processing fee as outlined in Title 15A NCAC 02H.1045(3). Permit issued this the 9th day of July 2020. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION n, :2 .�X, Brian Wrector Division of Energy. Mineral and Land Resources By Authority of the Environmental Management Commission Page 4 of 4 I1FMI H t1,F (1NI Y Date Received I Fee Paid Permit Number ` o o Swa-05-I61g, 0 Sas ELc1 $ OSto l NC DEG Division of Energy, Mineral and Land Resources STATE STORMWATER: PERMIT RENEWAL APPLICATION FORM In accordance with 15A NCAC 2H.1045 3 , the current permit holder shall renew their high density permit 180 days prior to its expiration. Renewed permits are valid for a period of 8 years per Session Law 2011-398 (SB 781) Section 60. (c). This application form is for permit renewals only. A. PROJECT INFORMATION 1. State Stormwater Permit Number: SW8 051018 2. Project name: Tarawa Terrace II Housing 3. Project street address: XXX City: MCB Camp Leieune County: Onslow ZIP: 28542 4. What, if any, changes have been made to the project as permitted? N/A If the project has changed from the original approved plans, please complete SWU-101 fora Major Modification or Minor Modification Application form available at: https://deg.nc.gc v/aboui/divisions/energy mineral-land-resources/ener -mineral-land-rules/stormwater- ro ram/ ost-construction. B. PERMITTEE INFORMATION If changes to the permittee or project name have been made, please complete either the Permit Update form or the Permit Transfer form available at: https://deg.nc.gov/about/divisions/energy-mineral-land- resources/energy-mineral-land-rules/stormwater-program_ /post -construction. State Stormwater Permits do not automatically transfer with the sale of the property. 1. Current Permit Holder's Company Name/Organization: MCB Camp Lejeune 2. Signing Official's Name: Neal Paul 3. Signing Official's Title: Deputy Public Works Division 4. Mailing Address: MCB Camp Lejeune 1005 Michael Rd. City: MCB Camp ZIP : 28547-2521 S. Street Address: State: NC City: State: ZIP: 6. Phone: (910) 451-2213 Email: neal.paul@usmc.mil JUN 0 i BY: 7 Stormwater Permit Renewal Form Page 1 of 3 May 1 , C. SUBMITTAL REQUIREMENTS Submit the application package to the appropriate DEMLR Regional „Office (Coastal, SA Waters) or DEMLR Central Office (Urbanizing Areas Ph 2, USMP, Non -Coastal HQW%ORW). Only applications packages that include all required items listed below will be accepted and reviewed. Initial each item below to indicate that the required information is provided in the application package: 1. A permit application processing fee of $505.00 payable to NCDEQ. A 2. One original signed hard copy and one electronic copy of this completed form. The signing official named on this application to represent the current permittee must meet one of the following: a. Corporation — a principle executive officer of at least the level of vice-president; b. Limited Liability Company (LLC) — a manager or company official as those terms are defined in G.S. 57D "North Carolina Limited Liability Company Act;" c. Public Entity — a principal executive officer, ranking official, or other duly authorized employee; d. Partnership or limited partnership — the general partner; e. Sole proprietor; or f. Letter of authorization signed by one of the signatories noted in a — e above authorizing the signature of another entity. 3. One hard copy and one electronic copy of recorded documents required by the original permit that have not yet been received by DEMLR, including: deed restrictions, protective covenants, condominium/planned community declaration and easements. If the project has been built, include documentation that the maximum BUA per lot or maximum total BUA has not been exceeded. If the project has not been built, include a signed agreement that the final recorded deed restrictions and protective covenants will be submitted at a later date. 4. O&M Agreements, Please select one: ® I have a copy of the current recorded O&M Agreement for all SCMs, and I will continue to keep this on file with the permit; or ❑ I do not have a copy of the current recorded O&M Agreement for all SCMs and am requesting a copy be sent to me. I agree to keep this on file with the permit. 5. Designer Certifications, Please select one: ® A copy of the certification(s) confirming that the project was built in accordance with the approved plans have been previously provided to the Division; or ❑ A copy of the certification(s) confirming that the project was built in accordance with the approved plans are enclosed; or ❑ The project has not yet been built. 6. [IF APPLICABLE] If the project has been built, one original hard copy and one electronic copy of a signed, sealed, and dated letter from a licensed professional stating that the SCMs have been inspected, and that they have been built and maintained in accordance with the permit. 7. [IF APPLICABLE] When the permittee is a corporation or a limited liability corporation (LLC): Provide one hard copy and one electronic copy of documentation from the NC Secretary of State, or other official documentation, which supports the titles and positions held by the persons listed in Section C.2 per 15A NCAC 2H. 1043(3)(b). https://www.sosnc.gov/online_ services/search/by title/ Business Registration EC`I%.r,z 8Y: Stormwater Permit Renewal Application Form Page 2 of 3 May 11, 2018 D. PERMI EFS CERTIFICATI N the person legally responsible for the permit, certify that I have a copy of the Permit and O& greement on site (or I will obtain a copy and it will be kept on site), that I am responsible for the performance of the maintenance procedures, and the site has been and will be maintained according to the O&M Agreement and approved plans. I agree to notify DEMLR of any problems with the SCMs or built -upon area and to submit the proper forms to modify or transfer the permit prior to any changes to the project, SCMs, or ownership. All information provided on this permit renewal application is, to the best of my knowledge, correct and e. Signature: Date: 3A10-6 this the ©� day execution 04hodpwing instrument. Witness my hand and official seal, W No ilSignIqAIS ► 1 My co`O 4zew)p IVA b N a►► a Notary Public for the State of do hereby certify personally appeared before me 20J�, and acknowledge the due JOIN BY. Stormwater Permit Renewal Application Form Page 3 of 3 May 11, 2018 D. PERMITTEE'S CERTI JCATiON the person legally responsible for the permit, certify that I have a copy of the Permit and O&M Agreement on site (or I will obtain a copy and it will be kept on site), that I am responsible for the performance of the maintenance procedures, and the site has been and will be maintained according to the O&M Agreement and approved plans. I agree to notify DEMLR of any problems with the SCMs or built -upon area and to submit the proper forms to modify or transfer the permit prior to any changes to the project, SCMs, or ownership. All information provided on this permit renewal application is, to the best of my knowledge, corr ct and completes L Signature: 9, Date: � a Notary Public for the State of do hereby certify personally appeared before me this the ;z!2.i day of 120_, and acknowledge the due execu`iP,pi the forgoing instrument. Witness my hand and official seal, (N ea19'� 00TgRy i{aAcv Signatur����`i JU14 0 2 w {� BY: Stormwater Permit Renewal Application Form Page 3 of 3 May 11, 2018 r 3 E owCL N 3 E. J � U 00 O 0 Go N .E L 0 a 7- + f O r O W) O co .E a m m 3 E z 0 co (D 4 g > m 7 0 O X E� � ~ O o ry O o U � co J Attachment C - Permitting History Tarawa Terrace II Permit No. SW8 051018 Approval Date Pennit Action B1MS Version Description of the Changes 12/13/2005 Original Approval 1.0 Permit includes two wet ponds 10/17/2008 Major Modification 1.1 Permit expands to five wet ponds 7/30/2009 Transfer 1.2 Ownership clarification to MCB 7/10/2020 Renewal 2.0 New expiration is 12/13/2027 Page 1 of 1 Central Files: APS — SWP 7/10/2020 Permit Number SW8051018 Permit Tracking Slip Program Category Status Project Type State SW Active Renewal Permit Type Version Permit Classification State Stormwater 2.00 Individual Primary Reviewer Permit Contact Affiliation dan.sams Coastal SWRule Coastal Stormwater - 1995 Permitted Flow Facility Facility Name Major/Minor Region Tarawa Terrace Two Housing Replacement Minor Wilmington Location Address County Tarawa Ter II Onslow Facility Contact Affiliation Camp Lejeune NC 28547 Owner Owner Name Owner Type Commanding Officer Marine Corps Base Camp Lejeune Government - Federal Owner Affiliation Robert A. Lowder 12 Post Ln Dates/Events Camp Lejeune NC 2854725, Scheduled Orig Issue App Received Draft Initiated Issuance Public Notice Issue Effective Expiration 12/13/2005 6/2/2020 7/10/2020 7/10/2020 12/13/2027 Regulated Activities Requested /Received Events State Stormwater - HD - Detention Pond Outfall Waterbody Name Streamindex Number Current Class Subbasin Burd, Tina J From: Burd, Tina J Sent: Thursday, June 18, 2020 3:15 PM To: Barraco CIV Talia M Subject: SW8 051018 - Tarawa Terrace li Housing The Wilmington Regional Office of the Division of Energy, Mineral and Land Resources (Stormwater Section) accepted the Stormwater Permit Renewal Application and $505.00 fee for the subject project on June 2, 2020. The project has been assigned to Dan Sams and you will be notified if additional information is needed. Best Regards, Tina Burd Administrative Associate II Wilmington Regional Office Division of Environmental Assistance & Customer Service Phone 910-796-7215 NCDEQ Wilmington Regional Office 127 Cardinal Drive Ext. Wilmington, NC 28405 Email correspondence to and from this address is subject to the !North Carolina Public Records Law and may be disclosed to third parties. Application Completeness Review Checklist (Non -Transfers) - Short Version Project Name: ` V A —re P_aq� T E, HDJ SI J4 ezPL. Date Delivered to WIRO: % Zd2.0 Project County/Location: Qh1�5LDl.� RIMS Received/Accepted Date: (Q Z q Rule(s): �2017 Coastal �2008 Coastal �1995 Coastal BIMS Acknowledged Date': Phase 11 Universal 1:11988 Coastal Permit Action: New Major Mod / Minor Mod enewal Permit Type; HD LD / LD Overall / HD &LD Combo General Permit / Offsite / Exempt / Rescission Development Type: Commercial / Residential Ajther �aST, i�ILI��Q Subdivided?: Subdivision or Single Lot jJ J_A Permittee Type & Documents Needed: Property Owner(s) Purchaser Lessee El Viable? ,rn(�B Viable? ElViabie? Deed D Purchase Agmt Lease Not Subdivided: Deed Subdivision: Common Area Deed Paperwork Application Fee: M$505 (within 6mo) Check#(s): F]Su ppiementz (1 new form or for older forms FlO&M2 Soils Report (lofil or PP) Calculations (signed/seoled) Deed Restrictions, if subdivided Project Narrative F-1USGS Map (or on file?) Subject to SA?: Plans (2 Sets) ElPE Certification Electronic Copies Easements, Recorded (2017 Rules) NOTES: 'Enter BIMS Acknowledged Date on this Sheet New Permit #2: Existing Permit #: '. Oro, aJ J I7 (_8 Expriation Date3: 1 Z 113 zb11? ElOffsite to SW8: y tot is in Master Permit? l 0PE Cert on File? F-1HOA Developer 13 Viable? Viable? Election Minutes 1 original perSCM) ❑ No Fee Y / N Subject to ORW?: Y / N For New Projects -Enter New Permit # on Supplements & Deed Restiction Templates, aif w/in 6 months and they are requesting a mod, STOP. Needs a renewal first. ENTAILED ENGINEER DATE: REVIEWER NAME: Comments: G:WQ\\\Reference Libra ry\Procedures\Checklists\Completeness Review Checkli5t_202001 31 01 DWQ USE ONLY Date Received Fee Paid Permit Number -U �% v3�ss LJ a 5101 State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This forrrr pray be photocopicd for use as an orighral I. GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual, etc. who owns the project): Atlantic Marine Corps Communities LLC C e% ti5 m l~ —'(�) CRvr p Lg4'X\-z- 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Dale Connor, Executive Manager �Q<- G5 Ty►Q! VIiQ ?re_`2''4Nk O� "e, � `ag� i 3. Mailing Address for person listed in item 2 above: g C MUV\��1�CFi � C , 4v— mGngov'C�c�\ rRevn X. 1801 West F-nd Ave., Suite 1700 ANIQL hv.'At CiN Nashville State:'1'N Zip:37215 �Zcxr Phone: (615 ) 324.7548 Fax: Emailclale.connor«actuslendlease.com 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): 5. Location of Project (street address): City:Camp Lejeune County:Onslow Zip:28543 6. Directions to project (from nearest major intersection): Travelling east on Lejeune Blvd /NC_ST RTE 24 turn right onto Tarawa Blvd and just past Bougainville Dr. phase five is on the right and phase six is on the left. 7. Latitude:34° 43' 57" N Longitude:77° 22' 48" W of project S. Contact person who can answer questions about the project: Name:Thomas 1. Davis,-P.E._ Telephone Number: (615 ) 385.4144 Email:tdavis@1eainc.com IL PERMIT INFORMATION: 1. Specify whether project is (check one): ❑New ❑Renewal ZModification 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing permit numberSW8 051018 and its issue date (if known)1211312005 3. Specify the type of project (check one): ❑Low Density EDFfigh Density ❑Redevelop ❑General Permit ❑Universal SMP ❑Other 4. Additional Project Requirements (check applicable blanks; information at r iM1 d's 2 4 to p�r�2008 m'�t an be Form SWU-l01 Version 03.27.08 Page of4 SE>° BY: t. r obtained by contacting the Customer Service Center at 1-877-623-6748): ❑CAMA Major ®Sedimentation/Erosion Control ❑404/40t Permit ®NPDES Stormwater 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. Stormwater will be conveyed throuqh storm drain inlets and pipes and also sheet flow to a detention pond located in the central open area of phase 6. Also, stormwater will be conveyed in the same fashion to two detention ponds located on the north and south sides a of an unnamed tributary to North east Creek. 2. Slormwater runoff from this project drains to the See Attached River basin. 3. 'Total Property Area: See Attached acres 4, Total Wetlands Area: See Attached acres 5. '100' Wide Strip of Wetland Area: See Attached acres (nut applicable if rry Wetlands exist on site) 6. Total Project Area**:See Attached acres 7. Project Built Upon Area:See Attached % 8. How marry drainage areas does the project have?See Attached 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. For hieh density oroiects. comolete the table with one drainage area for each eneineered stormwater device. Basin Information Drainage Area 1 Drainage Area 2 l:eceiving Stream Name See Attached See Attached Stream Class & Index No. See Attached See Attached Total Drainage Area (sf) See Attached See Attached On -site Drainage Area (so See Attached See Attached Off -site Drainage Area (so See Attached See Attached Existing Impervious Area (so See Attached See Attached Proposed Impervious Area (so See Attached See Attached %, Impervious Area (total) See Attached See Attached impervious Surface Area Drainage Area 1 Drainage Area 2 On -site Buildings (so See Attached See Attached On -site Streets (so See Attached See Attached On -site Parking (so See Attached See Attached On -site Sidewalks (so See Attached See Attached Other on -site (so See Attached See Attached Off -site (so See Attached See Attached Total (so: See Attached See Attached Impervious area is defined as fire biulf upon area including, but not Innrted to, buildings, roads, parking areas, sidewalks, gravel areas, etc. **Total project area slurp be calculated based rrrr fire current policy regardirrq inclusi M of Wetlands irr the wilt ripen area percentage calculation. This is [lie area used to calculate percent project built upon area (BLIA). 10. I -low was the off -site impervious area listed above derived? IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS Form SWU-101 Version 03.27.08 Page of 4 SEP 2 4 7.008 BY: f i 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, sire and the allowable built -upon area for each lot must be provided as an attachment. Forms can be downloaded from littpJlh2o.enr.state.IIC.us/su brnp for•ms.htm - deed restrictions. Form DRPC-1 Hif;h Density Commercial Subdivisions Form DRPC-2 High Density Developments with Outparcels Form DRPC-3 High Dcnsity Residential Subdivisions Form DRPC-4 Low Density Commercial Subdivisions Form DRPC-5 Love Density Residential Subdivisions Form DRPC-6 Low Density Residential SLIbdIVi5iorlS with CLlrb 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. Forms can be downloaded from forrns.htm. Form SW401-Low Density Low Density Supplement Form SW401-Curb Outlet System Curb OLrtlet System Supplement Form SW401-Off-Site System Off -Site System Supplement Form SW40"1-Wet Detention Basin Wet Detention Basin Supplement Form SW401-Infiltration Basin Infiltration Basin Supplement Form SW401-Infiltration Trench Underground Infiltration Trench Supplement Form SW401-Bioretention Cell Bioretention Cell Supplement Form SW401-1-evei Spreader Level Spreader/Filter Strip/Restored Riparian Buffer Supplement Form SW401-Wetland Constructed Wetland Supplement Form SW401-Grassed Swale Grassed Swale Supplement Form SW401-Sand Filter Sand Filter Supplement Form SW401-Permeable Pavement Permeable Pavement Supplement RjEr�r�TF SEP 2 4 ZD08 Fonn SWU-101 Version 03.27.08 Page of r 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 maps.lnm) 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 • Origival and ont! copy of the Deed Restrictions & Protective Covenants Form (if u/b required as per Part IV above) • Original of the applicable Supplement Form(s) and O&M agreement(s) for each BMP `T • Permit application processing fee of $505 (Express: $4,000 for I -ID, $2,000 for LD) payable to NCDENR S • Calculations & detailed narrative description of stormwater treatment/managementY ���� • Copy of any applicable soils report • Two 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 pro pperty/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) VI1. 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. (ex. designing engineer or firm) Designated agent (individual or firm):Thomas J. Davis P.E. Littlejohn Engineering Associates Mailing Address:1935 21" Ave. S City:Nashville State:"1N Zip:37212 Phone: (615 ) 385.4144 Emai L•tdavis << leainc.com Vill. APPLICANT'S CERTIFICATION 1, Dale Connor, Execrative Manygt r, cerli best of my knowledge, correct and tha that the required deed restrictions and complies with the requirements of 15A Signature: Fax: (615 ) 3854020 that the information included on this permit application form is, to the project tivill be constructed in conformance with the approved plans, roe i c covenants will be recorded, and that the proposed project IC 2H .1000. Date: •��- AVKD S E P 2 4 2008 Donn S W U-101 Version 03.27.08 Page of 4 BY" x O N N o (a N N M N CO o O M - N O M O) O (D O N h 00 00 M > N C Z Q Z CD N Ln 7 CO (hD OD ( O O N m(0 (D V 0 V O O M 0 co 0 O <p Q N O W cc L, Cl)C'7 O] N N M T c O CN a 0 o co N O c co l4 O N a¢ Z Z M� V r M r d N 07 (a O O O O h O M (1] N (O CO M co 0 0 LO a 7 L C a ti ff I- O m (Ir O 7 l6 N r(1 C a O d_ T In Cl) r LO (D o h M m M o (n h (� o 0 if1 .9 ro LO oN v 'T in _O of Cl)vQ d C o •R (O cp N M M N U � Y h 67 L to a) O N Z Z V M (D N M T O N a L 2 M N Z z o a o 00 0 o ov o co o C7 _ 4) h h 0 ' o N c`ry 00 N 0 0 U (a �` C O N N (n V h N co N O to (n T r ❑ a c ca O O -0 co N O O O O (9 m �_ O QOi (OD O( O r 0 N MO h V 0) 6 r c0 M (.j (a 0) � (, M O V (Q'•y V N r O r� Cl (A C (6 _ L M� r � Y N •x F � Q � 0(. a¢ o w C L N Z Z (+n N co N Q Z N R % ¢ a w a� a° A i7 O (D a (Cy N co O N O T M (D N M O V O C ❑ O M M h c It O M O) O V h 00 C N O X m w N QI t u ¢ m a � as `tu „�w Q¢ o m marmm c m c m aF m m mp u Y �Q CL CL ao 0 ar ��n c (n mVmQm M L c d a N i0 aC� cn N N t �000I'Z Oo C O da ❑a, .2co40 0 a U Q N N N31 AN a0G �ta t0 F0 0 T 0m OZ�0 O OO M w 2 ❑ OpOpOOa 'C -IIJ, p .W ' • t'I �g� 3—�� _, � ��� 7—Permit No. ���5, /o / (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form may be photocopied for use as an original DWO Stormwater Management Plan Review: A complete stormwater management plan submittal includes an application form, a wet detention basin supplement for each basin, design calculations, and plans and specifications showing all basin and outlet structure details. 1. PROJECT INFORMATION Tarawa Terrace II Project Name: Contact Person: Tom Davis Phone Number: 615 385-4144 For projects with multiple basins, specify which basin this worksheet applies to: Tarawa Boulevard Pond elevations Basin Bottom Elevation 5•0 ft. Permanent Pool Elevation 11.4 ft. Temporary Pool Elevation 12_6 areas Permanent Pool Surface Area 130,181 sq. ft Drainage Area 80.85 ac. Impervious Area 3�2.,K ac. tirli�D If volumes (door of the basin) (elevation of the orifice) (elevation of the discharge structure overflow) (water surface area at the orifice elevation) (on -site and off -site drainage to the basin) (on -site and off -site drainage to the basin) Permanent Pool Volume 555,343 cu. ft. (combined volume of main basin and forebay) Temporary Pool Volume 159,439 cu. ft. (volume detained above the permanent pool) Forebay Volume 121,175 cu, ft. (approximately 20% of total volume) Other parameters SA/DA i 2' 8 (surface area to drainage area ratio from DWQ table) Diameter of Orifice 6 in. (2 to S day temporary pool draw -down required) Design Rainfall 1 in. Design TSS Removal 2 20 % (minimum 85% required) Form SWU-162 Rev 3.99 Page I of 4 tiloalbrm -& v 2- 5-08 D S1018 Footnotes: When using the Division SAIDA tables, the correct SA/DA ratio for permanent pool sizing should be computed based upon the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the correct value for non- standard table entries. In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to provide 90% TSS removal. The NCDENR BMP manual provides design tables for both 85% TSS removal and 90% TSS removal. II. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit Application Form, the agent may initial below. if a requirement has not been met, attach ,justification. Applicants Initials X=? a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). :12 , b. The forebay volume is approximately equal to 20% of the basin volume. `r`n c.. The temporary pool controls runoff from the design storm event. d. The temporary pool draws down in 2 to 5 days. N/,ek e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow calculations) f. The basin length to width ratio is greater than 3:1. g. The basin side slopes above the permanent pool are no steeper than 3:1. -t,�� h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). -=i. Vegetative cover above the permanent pool elevation is specified. 1�=�t j. A trash rack or similar device is provided for both the overflow and orifice. NIA k. A recorded drainage easement is provided for each basin including access to nearest right - NIA of -way. I. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified prior to use as a wet detention basin. _ ��_ m.. A mechanism is specified which will drain the basin for maintenance or an emergency. III. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT 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) V does 0 does not incorporate a vegetated filter at the outlet. This system (check one) 0 does N does not incorporate pretreatment other than a forebay. Form SWU-IO2 Rev 3.99 Page 2 of 4 Maintenance activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system far sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. 2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. 3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc,) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream, etc.). 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 4.05 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 4.05 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (Jill in the blanks) v Permanent Pool Elevation 11.4 Sediment Re oval El. 7.35 75 0 Sediment Removai Elevation 7.35 -------- ----- 75 /o -- _ a Bottom Ele ation 6.0 %-----------------------: --- - - - - - - - - - - - - - - - - - - - - - - - - Bottom Elevation 6-0 25/a FOREBAY MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. 6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page of 4 7. All components of the wet detention basin system shall be maintained in good working order. I acknowledge and agree by my signature below that I am responsible for the performance of the seven 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:. __ L�,_i3t-�C� -�f '(RC—*V+'L Title: X�VVS Ac_ Addr Phon Sign Date: 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. a Notary Public for the State of County of 0A,416, , do hereby certify that fie/ personally appeared before me third day of ,!`" , and acknowledge the due 01 execution of the forgoing wet detention basin maintenance r uirements. Witness my hand and official seal, Izz SEAL My commission expires "T'f Form SWU-102 Rev 3.99 Page 4 of 4 Permit No. a l 1 (io be provided by DW& State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM WET DETENTION BASIN .'SUPPLEMENT This form may be photocopied for else as'an original - ' ' -��Management Flan Review: DWO Stormwater,_ A complete stormwater management plan, submittal includes an application form, a wet detention, basin supplement for each .basin, design calculations, and plans and specifications showing all basin and' outlet structure details. I. PROJECT ]INFORMATION= y -` ' Tarawa Terrace 11 Project Name: -' Contact Person: T&h Davis , - Phone Nuinbe`r ° {- `61S }.=38S-4144 For projects with multiple basins; specify which -i3ny scout Camp Road Pond',,',` basin this worksheet appites to elevations ". „•W ;1 Basin Bottom Elevation 4'5 v" ft. (floor of the basin) r Permanent Pool Elevation 9.5 ft;_ (elevation of the orifice).._ Temporarypool;Elevation 10.54 ft: (elevation•of the discharge structure overflow) . Permanent Pool Surface Area $1,831 sq.41, (water surface area at the orifice elevation) Drainage Area 37.60 ac,.- , . _ (on -site and off -site drainage to the basin) Impervious Area 15.8 ac. ' (on -site and off -site drainage to the basin) volumes .. µ ._ N . Permanent Pool Volurt'e 158 557 cu."ft: = 06bibined volume.of main basin and forebay} 58 690 Temporary -Pool Volume cu. ft. (volume detained dbove the permanenl pool);. ... ; Forebay. Volume 38,442 cu: ft. (approxtiriately 20% of total volume) Other: parameters SA/DA•1 Diameter of Orifice.; - Design Rainfall Design TSS-Removal,2 Form S W U- 102 Rev 3.99 2.94 in. I. in. 90 % (surface area to drainage area ratio from DWQ- table) T a (1 to S day temporary pool 4lr zdown required) ... -- (minimum 85% required) Page 1of4 lllb�'�D� - a!retl .2- Footnotes: Tws O3 / D918 When using the Division SA/DA tables, the correct SA/DA ratio for permanent pool sizing should be computed based upon the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the correct value for non- standard table entries. In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to provide 90% TSS removal. The NCDENR BMP manual provides design tables for both 85% TSS removal and 90% TSS removal. II. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A NC AC 2H .1008. Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit Application Form, the agent may initial below. If a requirement has not been met, attach justification. Applicants Initials a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). b. The forebay volume is approximately equal to 20% of the basin volume. c: The temporary pool controls runoff from the design storm event. 1�d. The temporary pool draws down in 2 to 5 days. 91A. c. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow calculations) f. The basin length to width ratio is greater than 3:1. -�� g. The basin side slopes above the permanent pool are no steeper than 3:1. h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). -CDD i. Vegetative cover above the permanent pool elevation is specified. j. - A trash rack or similar device is provided for both the overflow and orifice. NIA k. A recorded drainage easement is provided for each basin including access to nearest right- of-way. NIA 1. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified prior to use as a wet detention basin. A� _ m. A mechanism is specified which will drain the basin for maintenance or an.emergency. III. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT 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) x1 does 0 does not incorporate a vegetated filter at the outlet. This system (check one) 0 does X does not incorporate pretreatment other than a forebay. Form SWU-102 Rev 3.99 , Page 2 of 4 jle gorv�a _ /60 of rc tr, . 3�- Lj- w � 'qa i o r e Maintenance activities shall be performed as follows: 1. After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. 3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream, etc.). 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 3.75 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 3.75 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (fill in the blanks) 0 Permanent Pool Elevation 9.5 Sediment Re oval El. 5.75 75 a 5.75 ------- ----- -- a Sediment Removal Elevation 75 /o 5 ---------------------------------------------125% ----- Bottom Eie ation /a Bottom Elevation 4.5 FOREBAY MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. 6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-l02 Rev 3.99 Page 3 of 4 7. All components of the wet detention basin system shall be maintained in good working order. I acknowledge and agree by my signature below that I am responsible for the performance of the seven 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 Title Addi Phor Sign Date 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. a Notary Public for the State of /f-U�I Cei���i�G , County of air/Z/� , do hereby certify that .c V personally appeared before me this o7q'4 day of 4fA14 , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, G SEAL My commission expires C;�Y a tz 01— Form 5WU-102 Rev 3.99 Page 4 of 4 1 ,1 r Permit No. �O � 10 1 4 ._TY IOIP (to be provided by DWQ) ,• of w a r�R `' L' r NCDENR p 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 lll) must be printed, filled out and submitted afong with all of the required information. I. PROJECT INFORMATION Project name Tarawa Terrace II Phase 5 Contact person Thomas J. Davis, P.E. Phone number 615.385.4144 Date 10i712008 Drainage area number North Pond II. DESIGN INFORMATION Site Characteristics Drainage area 1,237,104.00 ft' Impervious area 514,008.00 ft' % impervious 41.55 % Design rainfall depth 1.50 in Storage Volume: Non -SR Waters Minimum volume required 65,558,00 ft' Volume provided 66,245.00 ft' 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 it Volume provided ft3 Peak Flow Calculations 1-yr, 24-hr rainfall depth 3.81 in Rational C, pre -development 0.35 (unitless) Rational C, post -development 0.60 (unitless) Rainfall intensity: 1-yr, 24-hr storm 6.23 inthr Pre -development 1-yr, 24-hr peak flow 20.56 0sec Post -development 1-yr, 24-hr peak flow 54.44 h3lsec PrelPost 1-yr, 24-hr peak flow control 33.88 f131sec Basin Elevations Basin bottom elevation 6.00 ft Sediment cleanoul elevation 7.75 ft Bottom of shelf elevation 12.50 ft Permanent pool elevation 13.00 ft SHWT elevation 12.83 ft Top of shelf elevation 13.50 ft Temporary pool elevation 14.24 ft Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 1 of 2 Permit No. 5 A 151012 MOO (to be provided by DWO) Ill. DESIGN INFORMATION Volume and Surface Area Calculations SA1DA ratio 390 (unitless) Surface area at the bottom of shelf 41,593.00 ft2 Volume at the bottom of shelf 156,584.00 ft' Permanent pool, surface area required 48,247.00 ft' Permanent pool, surface area provided 48,251 00 ft' OK Permanent pool volume 179,024.00 K' Average depth for SA/DA tables 3.71 ft OK Surface area at the top of shelf 56,501,00 ftz Volume at the top of shelf 250,185.00 ft3 Forebay volume 38,364.00 ft' Forebay % of permanent pool volume 21.43 % OK Temporary pool, surface area provided 61,917.00 ft' Drawdown Calculations Treatment volume drawdown time 2.93 days OK Treatment volume discharge rate 0.26 fil Pre -development 1-yr. 24-hr discharge 20.56 ft'Is OK Post -development 1-yr, 24-hr discharge 6.43 ft3ls OK Additional Information Diameter of orifice 3.5 in Design TSS removal 90 % Basin side slopes 3,00 :1 OK Vegetated shelf slope 10.00 :1 OK Vegetated shelf width 10.00 ft OK Length of flowpath to width ratio 3.00 :1 OK Length to width ratlo 4.11 :1 OK Trash rack for overflow & orifice? Y (Y or N) OK Freeboard provided 1.24 ft OK Vegetated filter provided? NIA (Y or N) OK Recorded drainage easement provided? NIA (Y or N) OK Capures all runoff at ultimate build -out? 'Y (Y or N) OK Drain mechanism for maintenance or emergencies Pump out "Approximately 24,348 SF of BUA Bypasses North & South Ponds Form SW401-Wet Detention Basin-Rev.4 Parts I. & If. Design Summary, Page 2 or 2 Permit (fo be provided by DWQ) III. REQUIRED ITEMS CHECKLIST 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. _ C;GN 1. Plans (1" 50' or larger) of the entire site showing: Dq tmlw Design at ultimate build -out, Off -site drainage (if applicable), CS-0-7 Delineated drainage basins (include Rational C coefficient per basin), Basin dimensions, Pretreatment system, High flow bypass system, Maintenance access, Proposed drainage easement and public right of way (ROW), Overflow device, and Boundaries of drainage easement. 2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing: �r Outlet structure with trash rack or similar, Maintenance access, Permanent pool dissensions, Forebay and main pond with hardened emergency spillway, Basin cross-section, Vegetation specification for planting shelf, and If A Filter strip. 3, Section view of the dry detention basin (1" = 20' or larger) showing: 11 Side slopes, 3:1 or lower, Pretreatment and treatment areas, and Inlet and outlet structures. _ C.& T,1 .cs 1 4. if the basin is used for sediment and erosion control during construction, clean out of the basin is specified l� on the plans prior to use as a wet detention basin. i �ytt p 5. A table of elevations, areas, incremenlal volumes & accumulated volumes for overall pond and for forebay, to verify volume provided. $. A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized. .ATTcmtj 7. The supporting calculations. &:X� A�TT6"trtj 8. A copy of the signed and notarized operation and maintenance (O&M) agreement. u/dj �A 9. A copy of the deed restrictions (if required). �ep10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County soil maps are not an acceptable source of soils information. R�' C�+ T�T�.- 1 SEP 2 4 7008 BY: Form SW401-Wet Detention Basin-Rev.4 Part Ili. Required Items Checklist, Page 3 of 3 Permit No. 5\9,1 05 lO IF (to be provided by D WO) �7 OF W k T�9 T • " o� pG � y NCDENR Q 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 18) must be printed, filled out and submitted along with all of the required information. I. PROJECT.INFORMATION Project name Tarawa Terrace it Phase 5 Contact person Thomas J. Davis, P.E. Phone number 615.385.4144 Date 1017/2008 Drainage area number South Pond II. DESIGN INFORMATION" Site Characteristics Drainage area 650,351,00 f? Impervious area 246,560.00 ft2 % impervious 37.91 % Design rainfall depth 1.50 in Storage Volume: Nan -SR Waters Minimum volume required 31,803 00 ft3 Volume provided 39,582.00 ft' Storage Volume: SR Waters 1-yr, 24-hr runoff depth in Pre -development 1-yr, 24-hr runoff f13 Post -development 1-yr, 24-hr runoff rya Minimum volume required It Volume provided fl3 Peak Flow Calculations 1-yr, 24-hr rainfall depth 3.81 in Rational C, pre -development 0.35 (unitless) Rational C, post -development 0.60 (unitless) Rainfall intensity: 1-yr, 24-hr storm 6.23 inlhr Pre -development 1-yr, 24-hr peak flow 10.71 ft3lsec Post-developmenl 1-yr, 24-hr peak flow 27.22 ft3lsec PrelPost 1-yr, 24-hr peak flow control 16.51 01sec Basin Elevations Basin bottom elevation 11.00 ft Sediment deanout elevation 12.75 ft Bottom of shelf elevation 17.50 ft Permanent pool elevation 18.00 h SHWT elevation 17.66 fi Top of shelf elevation 1850 ft Temporary pool elevation 19,00 ft Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Pagel of 2 I Permit No. 5W 9 95 j 01y MO (to be provided by D WQ) !I. DESIGN INFORMATION Volume and Surface Area Calculations SAIDA ratio 4.05 (unilless) Surface area at the bottom of shelf 28,632,00 ft2 Volume at the bottom of shelf 102,508.00 f13 Permanent pool, surface area required 26,110 00 f12 Permanent pool, surface area provided 34,491.00 it OK Permanent pool volume 118,266.00 f13 Average depth for SAIDA tables 3.43 it OK Surface area at the top of shelf 40,559.00 ft' Volume at the top of shelf 137,008.00 ft3 Forebay volume 22,573.00 ft3 Forebay % of permanent pool volume 19.09 % OK Temporary pool, surface area provided 42,810.00 ft2 Drawdown Calculations Treatment volume drawdown time 3.08 days OK Treatment volume discharge rate 0.12 ft3Is Pre -development 1-yr, 24-hr discharge 1071 ft31s OK Post -development 1-yr, 24-hr discharge 3,43 ft31s OK Additional Information Diameter of orifice 2.5 in Design TSS removal 90 % Basin side scopes 3,00 :1 CK Vegetated shelf slope 10.00 :1 OK Vegetated shelf width 10.00 ft OK Length of flowpath to width ratio 3.00 :1 OK Length to width ratio 3.00 :1 OK Trash rack for overflow & orifice? Y (Y or N) OK Freeboard provided 1.00 ft OK Vegetated filter provided? Y (Y or N) OK Recorded drainage easement provided? N/A (Y or N) CK Capures afl runoff at ultimate build -out? 'Y (Y or N) OK Drain mechanism for maintenance or emergencies pump out `Approximately 24,348 SF of BL1A Bypasses North & South Ponds Form SW401-Wet Detention Basin-Rev.4 Parts I. & 11. Design Summary, Page 2 of 2 i Permit No.��,� a(�� Q�� rnQD (to be provided by DWO) Ill. REQUIRED ITEMS CHECKLIST 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 SheetNo. C_� 'f •Ub 1. Plans (1" - 50' or larger) of the entire site showing: ��cHlf5ll Design at ultimate build -out, Off -site drainage (if applicable), G S•01 Delineated drainage basins (include Rational C coefficient per basin), Basin dimensions, Pretreatment system, High flow bypass system, Maintenance access, Proposed drainage easement and public right of way (ROW), Overflow device, and Boundaries of drainage easement. T -�— rS-cZ 2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing: Outlet structure with trash rack or similar, C �� �•0(p Maintenance access, Permanent pool dimensions, Forebay and main pond with hardened emergency spillway, Basin cross-section, Vegetation specification for planting shelf, and Filter strip. 3. Section view of the dry detention basin (1" = 20' or larger) showing: Side slopes, 3:1 or tower, Pretreatment and treatment areas, and Inlet and outlet structures. I . c2t 4. it 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. i-p ,QYx t tHr%j 5. A table of elevations, areas: incremental volumes & accumulated volumes for overall pond and for forebay, to verify volume provided. 6 A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized. -t- ej 7. The supporting calculations. -�T�r� E•a� 8. A copy of the signed and notarized operation and maintenance (0&M) agreement. 9. A copy of the deed restrictions (if required). 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County soil maps are not an accept&e source of soils information. Form SW401-Wet Detention Basin-Rev.4 LBY:SEP 2 4 J Part III. Required Items Checklist, Page 3 of 3 Permit No. (to be provided by DWQ) NCDENR a 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 111) must be printed, filled out and submitted along with all of the required information. I. PROJECT INFORMATION Project name Tarawa Terrace li Phase 6 Contact person Thomas J. Davis, P,E. Phone number 615.385.4144 Date 10f712008 Drainage area number TT6 Pond II. DESIGN INFORMATION Site Characteristics Drainage area 1,716,264,00 ft' Impervious area 645,088.00 ft2 % impervious 37.59 % Design rainfall depth 1.50 in Storage Volume: Non -SR Waters Minimum volume required 83,299.00 ft3 Volume provided 86,206.00 h3 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 ft, Volume provided ff3 Peak Flow Calculations 1-yr, 24-hr rainfall depth 3.81 In Rational C, pre -development 0.35 (unitless) Rational C, post -development 0.60 (unitless) Rainfall intensity: 1-yr, 24-hr storm 6.23 inlhr Pre -development 1-yr. 24-hr peak flow 28.37 0sec Post -development 1-yr, 24-hr peak flow 64.74 ft3lsec PreiPost 1-yr, 24-hr peak flow control 36.37 fi3lsec Basin Elevations Basin bottom elevation 7.50 ft Sediment cleanout elevation 9.38 It Bottom of shelf elevation 14.50 ft Permanent pool elevation 15.00 It SHWT elevation 14.83 It Top of shelf elevation 15.50 ft Temporary pool elevation 16.14 ft Form SW 401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 1 of 2 Permit N } {to be provided by QWQ) 111, DESIGN INFORMATION 4 Volume and Surface Area Calculations SNDA ratio 3.30 (unitless) Surface area at the bottom of shelf 58,495.00 ft2 Volume at the bottom of shelf 233,953.00 ft3 Permanent pool, surface area required 57,323.00 it Permanent pool, surface area provided 66,137.00 h2 OK Permanent pool volume 265,091,00 f13 Average depth for SA/DA tables 4.01 —ft OK Surface area at the top of shelf 72,284.00 ft2 Volume at the top of shelf 299.685,00 ft3 Forebay volume 53,821.00 ft' Forebay % of permanent pool volume 20.30 % OK Temporary pool, surface area provided 79,445.00 fe Drawdown Calculations Treatment volumed rawdown time 301 days OK Treatment volume discharge rate 0.32 ft31s Pre -development 1-yr, 24-hr discharge 28.37 ft'!s OK Post -development 1-yr, 24-hr discharge 6,52 ft'/s OK Additional Information Diameter of orifice 4 in Design TSS removal 90 % Basin side slopes 3.00 :1 OK Vegetated shelf slope 10.00 ;1 OK Vegetated shelf width 10.00 ft OK Length of flowpath to width ratio 3.00 :1 OK Length to width ratio 2.09 :1 OK Trash rack for overflow & orifice? Y (Y or N) OK Freeboard provided 1.13 ft OK Vegetated filter provided? N/A (Y or N) OK Recorded drainage easement provided? NIA (Y or N) OK Capures all runoff at ultimate buiid-out? "Y (Y or N) OK Drain mechanism for maintenance or emergencies Pump out 'Approximately 12.582 SF of BUA Bypasses Pond Form SW401-Wet Detention Basin-RevA Parts I, & il. Design Summary, Page 2 of 2 Permit No. �)R s (to be provided by DWQ) III. REQUIRED ITEMS CHECKLIST 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 protect. 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. DA 6ULTI Cg.o� Cl� 4. A 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, Proposed drainage easement and public right of way (ROW), Overflow device, and Boundaries of drainage easement. 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. _uZ 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. 4. If the basin is used for sediment and erosion control during construction, clean cut of the basin is specified on the plans prior to use as a wet detention basin. -xa-A > 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay, to verify volume provided. =fit!— ce" - t' . of 6. A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized. �e-tj 7, The supporting calculations. &=.grRcj 8. A copy of the signed and notarized operation and maintenance (O&M) agreement. 9. A copy of the deed restrictions (if required). � rTr�c+t j 10. A soils report that is based upon an actual field investigation, soil borings, and infiitration tests. County soil maps are not an acceptable source of soils information. 7Y,- P 2 4 2008 __._ Form 5W401-Wei Detention Basin-Rev.4 Part Ill. Required Items Checklist, Page 3 of 3 Permit Number: ���C55 10 LKw_to (to be provided by DWQ) Drainage Area Number: 'Ph 5—i��A�N Ply\,\ Wet Detention Basin Operation and Maintenance Agreement 1 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 BNIP. 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: - Innmediately 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 fertilizes{ 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 Bret 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 operation 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: Potential roblem: Flow 1 wilI remediate the roblem: 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 planta 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 Ion —approximately-approxiniately six inches. Form SW401-Wet Detention Basin O&M-Rev.3 Page 1 of 4 Permit Number:_ i &- )_ lvhk.,ksn (to be proryirled b_y D!1'Q) Drainage Area Number: BMP element: Potentialproblem: I•low 1 will renlediate theproblem: The inlet device: pipe or The pipe is clogged. Unclog the pipe. Dispose of the Swale sediment off -site. Tlie pipe is cracked or Replace the pipe. otlicrivlse danla ged. 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 problenis 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 seiiinlent storage. dispose of it in a location where it will not cause impacts to streams or the 15N1 P. Erosion has occurred. Provide additional erosion Protection such as reinforced turf matting or riprap if needed to revent 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 ]lest 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 flying. 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 seiiinlent and storage depth. dispose of it in a location where it will notcause impacts to streams or, the BN1P. Algal growth covers over Consult a professional to remove 50% of the area. and control the algal growth. Cattails, phragnlites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (c10 not spray). the basin surface. I=orm SW401-Wet Detention Basin O&M-Rev.3 Page 2 of 4 Pcrmit Number:'S (.'�"k QS lc� (. (to be proi4ded by DH`Q) Drainage Area Number: BM 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 Dottom Elevatio 7.75 l 1 ----------------- IZO IZ E 13AY BASIN DIAGRAM aill in the blanks) Volume -ft Min. Sediment Storage Permanent Pool Elevation 13.0 Pool Sediment Removal Elevation 7.75 Volume 1-- ------ Bottom Elevation MAIN POND Form SW401-Wet Detention Basin O&M-Rev.3 Page 3 of 4 Sediment Storage Hermit Number:S(s—) to AKPI_4�10 (to be provided byDfVQ) l acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures lister! above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project rune Tarawa Terrace Phase 5 BMP (Iraivawe area number. North Pond Print namc:Dale Cot Tltle:ExCCLltiVC Man Address:1801 West Phorie:G 15.324.7548 Signature: Date: Note: The legally responsibic party should not be a liomeotivners association unless more than 50'% of' the lots have been sold and a resident of the subdivision has been named the president. 1, ��T�tctPC i� IN*� V_C;1 , a Notary Public for the State of 1t�^�JIS63�r� , County of �1J �ya,,� , do hereby certify that ?rrr•t� �ur� personally appeared before me this day of _OT_ , Ghpb2, and acknowledge the clue execution of the forgoi c detention basin maintenance requirements. Witness my hand and official seal, Ilk A N41 STATE ,2p=� OF . r rENNEEI: v ; NOzAny PU6LIC N EQUNZy'�` SEAL My commission expires a-5 �a .. jj Form SW401-Wet Detention Basin O&M-Rev.3 Page 4 of 4 k T f i 1 Permit Number: >4 s 015 i'D t$ (to be provided by DJJ"Q) Drainage Area Number: �ti6 - ")n,)�� '90 1�16 Wet Detention Basin Operation and Maintenance Agreement will keep a maintenance record on this Mill'. 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 BiVIP. The wet detention basin system is defined as the Bret 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. �y K After the wet detention pond is established, it should be inspected once a month and rn within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a n Coastal County). records of operation and maintenance should be kept in a known set �' location and must be available upon request. ," _o }�y co Inspection activities shall be performed as follows. Any problems that are found shall �iy� be repaired inunediately. v 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 soli if necessary to detention basin erosive gullies have formed. remove tl}e 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 1011g. approximately six inches. Form SW401-Wet Detention Basin 0&M-Rev.3 Page 1 of 4 Permit Number: 1715 mQb (to be provideel btu D H'Q) Drainage Area Number; BMP element: Potentialproblem: How I will remediate the roblem: The inlet device: pipc 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. ]SI'OSIOn is occurring in the Regrade the Swale if necessary to Swale. smooth it over and provide erosion control devices such as reinforced turf malting 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 sedimentand sediment storage. dispose of it in a location where it will not cause impacts to streams or the BN1P. 1-1.OSiOn 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 Elants 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 rernedy 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. TDO -1 E SEP 2 4?008 Form SW401-Wet Detention Basin O&M-Rev.3 I Page 2 of 4 i ; I Permit Numbe-:�s �R 0<5 (to be provided bY D6VQ) Drainage Area Nmnbcr: BM element: Potentialproblem: Flow 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 lama ed 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 ilito 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. BASIN DIAGRAM (fill in the blanks) p Permanent Pool Elevation 18.00 Sediment Removal . 12,75 Pe manes Pool ---------------- Volume Sediment Removal Elevation 12.75 Volume Bottom Elevatioi l 1.00 -ft Min. ------------------------------------------- ------ Sediment Bottom Elevation 11.00 1-ft N m. Storage Sediment Storage FORFBAY MAIN POND ET Dorm SW401-Wet Detention 13asin O&M-Rev.3 Page 3 of 4 Permit Number: (] S (to be provided fw Dlt'Q) I 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. Proica itame:Tarawa Terrace Phase 5 13NIP drahiage area numbe1-:South Pond Print name:Dale Connor Title:Executive_Manager. Addr Phon Sign" Date 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. I, PATt."L'(0, *W.J a Notary Public for the State of kr. c_-:516r County of ` �•�,J , do hereby certify that .QtS Cpnsvoct— personally appeared before me this clay of _.Q--wG„� tT , and acknowledge the due execution of the forgoi 3g w4 detention basin maintenance requirements. Witness my hand and official seal,u y; N,1A a NNq� a�-•• S7A7r_ .2 •D Tr<N OF � o SSSEFE = a ; N07ARY N C 0 U SEAL My commission expires I: SEA ,,Ong Form SW40I-Wet Detention Basin O&M-Rev.3 Page 4 of 4 I f ( I r J Permit Number: V �• 9f f ` �LJ (to Ue��ided by DJJ,Q) Drainage Area Number: Wet Detention Basin Operation and Maintenance Agreement i will keep a maintenance record on this 13MP. 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 StrL[CtUreS, safety of the public, and the removal efficiency of the SNIP. 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 ogre): ❑ 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 operation 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: I -low I will remediate the roblem: 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 grounil cover and water until it is established. Provide lime and a lication. one-time fertilizerapplication. Vegetation is too short or too Maintain vegetation at a height of Ion -approxiniately six inches. Form SW401-Wet Detention Basin O&M-Rev.3 Page I of 4 Permil Number: () s t (Drg m-e'D (to he proi!ided hy Dlt'Q) Drainage Area Number: 6MP 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 ",here it will not cause impacts to streams or the 13M P. Frosion 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 lien Ith. 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. Removethe sediment and storage depth. dispose of it in a location where it will not cause rmpaCtS to streams or the 13MP. Algal growth covers over Consult a professional to remove 50% of the area. and control the algal growth. Cattails, phragrnites or other Remove the plants by wiping there invasive plants cover 50% of with pesticide (do not spray). the basin surface. 1- CFT�TFD S E P 2 4 2008 Form SW401-Wet Detention Basin O&M-Rev.3 Page 2 of 4 Permit Nuniber: 5 (to be provided b_v DlVQ) Drainage Area Number: BMI' element: I'otentialproblem-. 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 re lace the outlet device. The receiving water hrosion 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 5.62 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 5.62 feet in the forebay, the sediment shall be removed. Sediment Removal Bottom Elevati BASIN DIAGRAM (fill in the blanks) 9.38 1 Pe maven\ -------------- - - Volume i 7.50 -ft Min. Sediment Storage FORE13AY Pool Permanent Pool Elevation 15.00 Sediment Rernoval Elevation 9.38 Volume ----------- ------ Bottom Elevation 7.50 2 1-ft 4r MAIN POND _- 11 "I. v E 5 E P 2 4 2008 15edlinent Storage Form SW401-Wet Detention Basin O&M-Rev.3 / Page 3 of 4 Permit Number: G_V_=-SOs 01mx (to be provi(le(( by DII'Q) acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to noti Fy DWQ of any problems with the system or prior to any chanties to the system or responsible party. Project name:Tarawa Terrace Phase 6 13rvIP rlr•arnage area nwnber:Wet Detention Pond Print namc:Dale Connor Title: Executive Manager Address:1801 West End Ave. Suite 1700 Nashville, TN 37203 Phone:615.324.7548 C-,\ I pI i Signature: Date: 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. a Notary Public for the State of Ie'3-0G50%wzr , County of �L�Sa.J , do hereby certify that J 3 personally appeared before me this 154- day of �t- , ?p=, and acknowledge the due execution ofthe Forgoing et detention basitl maintenance rccluircments. Witness my hand and official seal, ,,,IIII1I##"d, SNre OF a T NESSEEAIO-rAv R •"V$t /C .• It SOU NZ1 011l11i IIIAti4' SEAL My commission expires a.3 20a Form SW401-Wet Detention Basin O&M-Rev.3 Page 4 of 4 WET DETENTION BASIN CALCULATIONS for. TARAWA BOULEVARD POND M. Me BOY SCOUT CAMP ROAD POND PROJECT NAME: TARAWA TERRACE II STORMWATER PROJECT NUMBER: SW8 051018 -7 a ,• 31144 e>.5 ''l;GINe" 0A Swlb WM b Prepared By: Littlejohn Engineering Associates 1935 Twenty -First Avenue South Nashville, TN 37212 615-385-4144 Tarawa Boulevard Pond Calculations Ilk, Drainage Area: Off -Site Drainage Area = 28.8 AC (40% Impervious) Tarawa Terrace 11 Drainage Area = 52.05 AC Total Drainage Area = 80.85 AC Impervious Area = 33.82 AC Percent Impervious - 42% Permanent Pool Depth = 5-FT Pond Surface Area: f SA/DA Ratio ='. 2.94 (From NC DENR BMP Manual SA/DA Ratios for Coastal. Counties) Surface Area Required = (2,94/100)"80.85 AC = 2.36 AC = 103,542 SQ-FT Surface Area Provided = 130,181 SO -FTC Volume to be Controlled: Volume (V) = Design Rainfall " R_v " Drainage Area R_v = 0.05+0.009"1 1= Percent Impervious = 42 R_v = .43 WIN Design Rainfall = 1-IN V = (1-IN)" 0.43 INIIN " 1 FT/121N ' 80.85 AC V = 2.90 AC -FT 126,199 CU-FT Drawdown Time Calculations: Temporary Pool Depth: 12.39 - 11.42 = 0.97 FT Average Head on Orifice: h = 0.48 FT Orifice Equation - O = C_d ' A " (2'g'h)AJ/2 C d = 0.6 4-IN ORIFICE A = 0.087 SO -FT Q = 0.29 CFS V10 = 433,504 SECONDS 6.02 DAYS 6-IN ORIFICE A = 0.196 SO -FT Q = 0.66 CFS V/Q = 192,668 SECONDS W 2.23 DAYS Therefore a 6-IN Orifice will provide acceptable drawdown time. TARAWA BOULEVARD POND STAGE -STORAGE TABLE ELEVATION F) SURFACE AREA __ _(SQ F ELFV. VOLUME (CU FT) SUB -VOLUME CU FT) SURFACE AREA AC 5.80 0 0 0.00 6.00 79,496 5.300 5.300 1.82 7,00 67,074 83,249 88,549 2,00 8.00 94,956 90,980 119,529 2.18 9.00 103,364 99,125 278.653 2.37 10.00 112,542 107,911 186,564 2.58 11.00 123_'628 118,023 504,587 2.84 11,40 130,131 ✓ 50,755 555,343 2.99 12.00 132,245 78,727 / 634,070 3:04 12.6U 136,807 80,712 714,782 3.14 Following page Illustrates the stage -storage tahle hroken down into (brebay stage -storage and main pond stasC-storage' I f':1r►�4AYY /"� IJ �-' V LG Y/`�;G Y 1 U N 1:-�' - MAIN.POND STAGE STORAGE TABLE 0 N ELEVATION (Pr) SURFACE AREA S Fr] ELEV. VOLUME (CU FT) SUB -VOLUME CU 1'1' 5.80 ' 0 0 6.00 66,142 4,409 4,409 7.00 70,921 68,518 72,927 8.00 75,802 73,348 146,275 9.00 80,952 78.363 224,638 10.00 86.100 83,513 308,151 11.00 91,349 98,712 396.862 I.40 95,191 37,305 434,168 12.00 96,670 57,558 491,725 12.60 100.143 59,041 550;766 r - r EAST FOREBAY STAG E-ST MGE TABLE ELEVA"1']ON (1-. r) SURFACE AREA (S l i) ELEV. VOLUME (CU 1�T) SUS -VOLUME (CU FT) 5.80 0 0 6.00 5,601 373 373 7.00 6,885 6,232 6,605 8.00 8,265 7;565 14,170 9.00 9,769 9,007 23,176 10.00 11,960 10,850 34,027 11.00 14,841 13,379 47,406 1 L40 16,230 6,212 53,618 12.00 16,531 9,828 63,446 12.60 16,964. 10,048 73,495 WEST FOREBAY STAGE -STORAGE TABLE ELEVATION (12"I") SURFACE AREA (SQ F'o ELEV. VOLUME (CU rI .SU13-VOLUNIF (CU FT) 5.80 0 0 6.00 7.753 517 517 7.60 9.268 8.499 9,016 8.00 '10;889 10,068 19,084 9.00 12,643 11,755 30,839 10.00 14,473 13,548 44,387 11,00 1:7,439 15,932 60,319. 1.1.40 18,760 7,238 67.557 12.00 19.044 11,341 78,898 12.66 19.700 11,623 90,521 Boy Scout Camp Road Pond Calculations Drainage Area: Total Drainage Area = 37.8 AC Impervious Area = 15.8 AC Percent Impervious = 42% Permanent Pool Depth = 5-FT Pond Surface Area: SA/DA Ratio = 2.94 (From NA�G DENR BMP Manual SAIDA Ratios for Coastal Counties) Surface Area Required = (2, 4/100)*37.6 AC = 1.11 AC = 48,153 SO -FT Surface Area Provided = 51,831 SQ-FT r Volume to be Controlled: Volume (V) = Design Rainfall " R_v ' Drainage Area R_v = 0.05+0.009"1 I = Percent impervious = 42 R v = .43 IN/IN Design Rainfall = 1-IN V = (1-tN) ' 0:43 IN/IN ` 1 FT/121N ` 37.6 AC V= 1.35 AC -FT 58,690 CU-FT v Drawdown Time Calculations: Temporary Pool Depth: 10.54 - 9.5 = 1.04 FT Average Head on Orifice: h = 0.52 FT Orifice Equation = 0 = C_d ` A " (2'g'h)^1/2 C d = 0.6 4-IN ORIFICE A = 0.087 SO -FT Q = 0.30 CFS VIQ = 193,696 SECONDS = 2.24 DAYS Therefore a 4-IN Orifice will provide acceptable drawdown time. BOY SCOUT CAMP ROAD POND STAGE -STORAGE TABLE ELEVATION (FT) SURFACE AREA (SQ FLEV, VOLUME (CU CI") SUES -VOLUME (CU fT) SURFACE AREA (AC) 4.40 0 0 0 0.00 4.50 30,216 1,007 1,007 0'.69 5.50 34,074 32.124 33,131 0.78 6.50 38,162 36,097 69,228 0.88 7.50 42,478 40,299 109,529 0.98 I 8.50 47,019 44,728 154,256 1.08 9.50 51,831 42,743 158,557 1.19 10.50 57,376 54,580 • , I 213,137= L32 11.50 61,683 59.517 272,653 1.42 12.50 64,626 63,149 335,802 1 1.48 Followinn page illustrates the stage -storage table broken downs into forebay stage -storage and main pond stage-storagc 50Y S couv "vZar.n T>C wn . lar4 FOREBAY STAGE -STORAGE TABLE ELEVATION SUKFACE AREA (SQ FT) ELEV. VOLUME (Cu r) SUB -VOLUME (Cu I: -I-) 4.40 0 0 0 4.50 6,659 222 222 5.50 8,011 7,325 7,547 6.50 9,479 8,735 16,281 7.5.0 11,062 10,260 26,542 8.50 12,760 11,901 38,442 ✓ MAIN POND STAGE -STORAGE TABLE ELEVATION (I'I SURFACE AREA SQ 1 I' ELEV. VOLUME (CU SU13-VOLUME CU FI 4.40 0 0 j 4.50 23.557 785 785 5.50 26.063 24,799 25.585 6.50 28,683 27.363 52,947 7.50 31,416 30,039 82,986. 8.50 34.259 32,827 1.15,814 9.50 51.831 -/ 42,743 SR,557 10,50 57,376 54,580 r 213,137 11.50 61,683 59,517 272,653 12.50 64,626 63,149 335,802 Tarawa Terrace II Overall Site Impervious Area Calculations Phase 1/School Site: Total Impervious Area = 371,984 SO -FT y Impervious Area Draining to Tarawa Boulevard Pond = 371,984 SO -FT Total Impervious Area = 417,098 SO -FT Impervious Area Draining to Boy Scout Camp Road Pond = 331,708 SO -FT Impervious Area Draining Off -Site as under Existing Conditions = 46,000 SO -FT Impervious Area Draining North to Future Phase Ponds = 39,390 SO -FT Phase 2a/Commun Ity Center: Total Impervious Area 43,577 SO -FT Impervious Area Draining to Boy Scout Camp Road Pond = 30,485 SO -FT Impervious Area Draining North to Future Phase Ponds= 13,092 SO -FT Phase Total Impervious Area = 538,430 SO -FT Impervious Area Draining to Tarawa Boulevard Pond = 282,410 SO -FT Impervious Area Draining to ✓ Boy Scout Camp Road fond = 231,520 SO -FT Impervious Area Draining Off -Site as under Existing Conditions = 24,500 SQ-FT 1 of 2 Phase 4• Total Impervious Area Impervious Area Draining to Tarawa Boulevard Pond = Impervious Area Draining to Boy Scout Camp Road Pond = Impervious Area Draining Norih ta."Future Phase Ponds = Phase 5: Total Impervious Area = Tarawa Terrace 11 Overall Site Impervious Area Calculations 491,530 SO -FT 315,680 SO -FT 106,850 SO -FT 69,000 SO -FT 585,174- SQ-FT Phase 6: Total Impervious Area W 696,144 SO -FT Total Project Impervious Area 3,143,937 SQ-FT "Detailed Breakdown of Impervious Area Calculations to follow 2 of 2 Buildings/Driveways: RoMds: Tarawa Terrace II Phase 1/School Site Impervious Area Draining to Tarawa Boulevard Pond Buildin • 1 Uniis Ogilding Area/Uni Tolal-Quildingv rea 1 29 3,200 92,800 1,200 34,800 11 0 3,300 0 1,600 0 111 8 3,200 25,600 1,300 10,400 V 10 4,300 1 43,000 1,420 14,200 VI 4 3,700 1 14,800 800 3,200 Building Area Phase 1 = 176,200 SO -FT Driveway Area Phase 1 = 62,600 SO -FT Name Width Length (FT) Area (SO. -FT) On-Streat Parkin Road "A" 28 2,150 60,200 0 Road "B" 28 660 24,080 0 Alle 16 280 4,480 0 Mews 20 430 8,600 0 Phase 1 Road Areas = 97,360 SO -FT Sidewalks: Length: 6,892 FT Width: 4 FT Phase 1 Sidewalk Area - 27,568 SOFT Trails: Length: 2,064 FT Width: 4 FT Phase 1 Trail Area = 8,256 SO -FT Impervious Area Draining to Tarawa Boulevard Pond = 371,984 SOFT Bu_il_din- sct /Driveways: Roads: Tarawa Terrace II Phase 2 Impervious Area Draining to Boy Scout Camp Road Pond it in u ldi A n€ T aLB ii in Ar riveyvaXre 1 19 3,200 60,800 1,200 22,800 II 2 3,300 6,600 1,600 3,200 111 5 3,200 16,000 1,300 6,500 V 15 4,300 64,500 1,420 21,300 VI 0 3,400 0 800 0 Building Area Phase 2 = 147,900 SOFT Driveway Area Phase 2 = 53,800 SOFT I Name Width Length (FT) Area (SO. -FT) On -Street Parkin Ha aru 26 930 24,180 0 Chosin 26 1,300 33,800 0 Hungnam 26 42 1,092 0 Road "D" 28 530 14,840 0 Tarawa 34 430 14,620. 0 Sidewalks: Phase 2 Road Areas = Phase 2 On -Street Parking = Length: 7,005 FT Width: 4 FT Phase 2 Sidewalk Area = Length: 3,364 FT Width: 4 FT Phase 2 Trail Area = Impervious Area Draining to Boy Scout Camp Road Pond (Phase 2) = 88,532 50-FT 0 SO -FT 28,020 SO -FT 13,456 SO -FT 331,708 SO -FT Buildings/Driveways: Roads: Tarawa Terrace II Phase 2 Impervious Area Draining Off -Site as under Existing Conditions Hungnam Place uitdi T #Units i1 i r Total ui! in re D 'v i riv 1 2 3,200 6,400 1,200 2,400 11 0 3,300 0 1,600 0 III 5 3,200 16,000 1,300 6,500 V 0 4,300 0 1,420 0 VI 0 3,700 0 800 0 Building Area Phase 2 = 22,400 SO -FT Driveway Area Phase 2 = 8,900 SO -FT Name I Width I Length (Fr) I Area (SO. -Fr) I an -Street Parkin Hun nam 1 26 450 1 11,700 1 0 Sidewalks,• Phase 2 Road Areas = 11,700 SO -FT Phase 2 an -Street Parking = 0 SOFT Length: 750 FT Width: 4 FT Phase 2 Sidewalk Area = 3,000 SOFT Total Impervious Area Draining Into Woods as in Existing Conditions (Phase 2) = 46,000 SO -FT Tarawa Terrace II Phase 2 Impervious Area Draining North to Future Phase Ponds Bvildings/Driveways: Bui in it in ilding Am Drive w4412jVni Total Coveway Am 1 3 3,200 9,600 1,200 3,600 II 1 3,300 3,300 1,600 1,600 ill 2 3,200 6,400 1,300 2,600 V 4 4,300 17,200 1,420 5,680 VI1 0 3,400 0 800 0 Roads: 11;3uiiding Area Phase 2 = 36,500 50-FT Driveway Area Phase 2 = 13,480 SO -FT Name Width Length {FT) Area (SQ.-Fr) On Street Parkin Ha aru 26 240 6,240 0 Guam 34 620 21,080 0 Tarawa 34 355 12,070 0 Phase 2 Road Areas = 39,390 5Q-FT Phase 2 On -Street Parking,= 0 SQ-FT .Sidewalks: Length; 1,858 FT Width: 4 FT Phase 2 Sidewalk Area = 7,432 SQ-FT Trails: Length: 1,000 FT Width; 4 FT Phase 2 Trail Area = 4,000 SQ-FT Total Impervious Area Phase 2 Total Impervious Area Contributing to Phase 516 Ponds (Phase 2) = 1001802 SO -FT 39,390 SO -FT Tarawa Terrace I I Phase 2a/Communiiy Center Impervious Area Draining to Boy Scout Camp Road Pond Buildings/Driveways: uTdin T : I gnl it in T t Tin Comm. Center 1 1 5,250 1 5,250 Building Area Phase 2a = 5,250 SO -FT Mlsc Concrete Phase 2a = 15,455 SO -FT Roads-. Name I Width I Length (FT) Area (So. -FT) On -Street Pa Phase 2a Road Areas = 0 - SO -FT Phase 2a Parking = 0 SO -FT idew Iles: Length: 2,445 FT Width: 4 FT Phase 2a,Sidewalk Area = 9,780 SOFT Total Impervious Area, Phase 2a Contributing to Boy Scout Camp Road Pond = 30,485 SO -FT f Tarawa Terrace 11 Phase 2a/Community Center Impervious Area Draining North to Future Phase Ponds Buildings/Driveways: i i e: Lgrigs I31'1 ina Area/UnTpla[13 uIlding 6M Driveway Argigunij Totgi riv A Roads: Sidewalks: Building Area Phase 2a = Parking Lot Area Phase 2a = Misc Concrete Phase 2a Phase 2a Road Areas = Phase 2a On -Street Parking = Length: 523 FT Width: 4 FT Phase 2a Sidewalk Area = Total Impervious Area Contributing. to Phase 516 Ponds (Phase 2a) _ 0 10,000 1,000 0 0 SQ-FT SQ-FT SQ-FT SO -FT SO -FT 2,092 SO -FT 13,092 SQ-FT f Tarawa Terrace II Phase 3 Impervious Area Draining to Tarawa Boulevard Pond Buildings/Driveways: Buildinge H Uni r U t T i t Nveway ArljTotal DrivewayAM 1 14 3,200 44,800 1,200 16,800 II 4 3,300 13,200 1,600 6,400 III 0 3,200 0 1,300 0 V 9 4,300 38,700 1,420 1 1 12,780 V1 13 3,700 48,100 800 1 10,400 Roads: Building Area Phase 3 = 144,800 SO -FT Driveway Area Phase 3 = 46,380 SO -FT !Name Width Len h (FT) Area (SO. -FT) Qn=Street Parkin Tula i 26 255 6,630 0 Ha aru 26 1,200 31,200 0 Alley "" 16 450 7,200 0 Road "E" 28 850 23,800 0 Sidewalks: Tr_ ails: Phase 3 Road Areas = 68,830 SOFT Phase 3 On -Street Parking = 0 SCE -FT Length: 5,600 FT Width: 4 FT Phase 3 Sidewalk Area = 22,400 SO -FT Length: 0 FT Width: 4 FT Phase 3 Trail Area = 0 SO -FT Total Impervious Area Contributing to Tarawa Boulevard Pond (Phase 3)= 282,410 SO -FT Tarawa Terrace 11 Phase 3 Impervious Area Draining to Say Scout Camp Road Pond Build cis/Driveways: Tyne:Buildiag i it I TMat.1501dingi Total Driveway -AM 1 16 3,200 51,200 1,200 19,200 II 0 3,300 0 1,600 0 111 1 3,200 3,200 1,300 1,300 V 6 4,300 25,800 1,420 8,520 VI 11 3,700 40,700 800 8,800 Buliciing Area Phase 3 = 120,900 SO -FT Driveway Area Phase 3 = 37,820 SO -FT Name Width len th Fr) Area (SO. -FT) On -Street Parkin >-12aru 26 1,100 28,600 0 Road "E" 28 600 16,800 0 Alley "" 16 600 9,600 0 ,Alley "South' 16 175 2,800 0 Sidewalks: rails: Phase 3 rtoaa Areas = Phase 3 On -Street Parking Length: 3,750 FT Width: 4 FT Phase 3 Sidewalk Area = Length: 0 FT Width: 4 FT Phase 3 Trail Area = Total Impervious Area Contributing to Boy Scout Camp Road Pond (Phase 3) = 01,500 SQ-FT 0 SO -FT 15,000, SO -FT 0 SO -FT 231,520 SO -FT Buildings/Driveways: Roadsi Tarawa Terrace II Phase 3 Impervious Area Draining Off -Site as under Existing Conditions Tulagi Place B it in T :#_V= ftUji r Una Total Uulld'nat Area/Unit Total Qriveway 1 0, 3,200 0 1,200 0 11 0 3,300 0 1,600 0 111 4 3,200 12,800 1,300 5,200 V 0 4,300 0 1,420 0 VI 0 3,700 0 800 0 Building Area Phase 3 = 12;800 SO -FT Driveway Area Phase 3 = 5,200 SO -FT Name I Width I Length (FT) Area (SO. -Fr) I On -Street Parkin Tula i 1 26 1 200 5,200 1 0 Sidewalks: Phase 3 Road Areas = 5,200 SO -FT Phase 3 On -Street Parking = 0 SQ-FT Length: 325 FT Width: 4 FT Phase 3 Sidewalk Area = 1,300 SOFT Total Impervious Area Draining Into Woods as in Existing Conditions (Phase 3) = 24,500 SOFT Budidings/Driveways: Roads: Tarawa Terrace II Phase 4 Impervious Area Draining to Tarawa Boulevard Pond # Un'ts. BuildingAr nlj TQ1a1Dui1djn2AWA 1 18 3,200 57,600 1,200 21,600 11 0 3,300 0 1,600 0 111 8 3,200 25,600 1,300 10,400 V 4 4,300 17,200 1,420 5,680 VI 1 5 3,700 18,500 800 4,000 Building Area Phase 4 = 118,900 SQ-FT ! Driveway Area Phase 4 = 41,680 SO -FT Name Width Length (FT) Area (SO. -FT) On -Street Parkin Tarawa 38 1,250 47,500 0 Bougainville 28 2,025 56,700 0 Mews "B" 20 450 9,000 0 Mews "C" 20 450 9,000 0 Mews "D" 1 20 450 91000 0 Si walks: Phase 4 Road Areas= 131,200 SQ-FT Phase 4 On -Street Parking = 0 SOFT Length: 4,550 FT Width: 4 FT Phase 4 Sidewalk Area = 18,200 SQ-FT length: 950 FT Width: 6 FT Phase 4 Trail Area = 5,700 SOFT Total Impervious Area Contributing to Boy Scout Camp Road Pond (Phase 4) = 315,680 SO -FT Buildings/Driveways: Roads: Tarawa Terrace li Phase 4 Impervious Area Draining to Boy Scout Camp Road Pond i i • q Units Idin A ni Ar riv A i Igiat Rriyeway Area 1 4 3,200 12,800 1,200 4,800 II 0 3,300 0 1,600 0 III 2 3,200 6,400 1,300 2,600 V 0 4,300 0 1,420 0 VI 3 3,700 11,100 800 2,400 Building Area Phase 4 = 30,300 SQ-FT Driveway Area Phase 4 = 9,800 SOFT r Name Width Length FT*) Area SO.- On -Street Parkin Tarawa 38 875 33,250 0 Mews "E" 20 475 9,500 0 Alley "5" 16 250 4,000 0 Nnase 4 Road Areas = 46,750 50-FT Phase 4 On -Street Parking = 0 SO -FT Sidewalks: Length. 1,325 FT wide,: 4 FT Phase 4 Sidewalk Area = 5,300 SO -FT Trails; Length: 2,450 FT Width: 6 FT Phase 4 Trail Area = - 14,700 SO -FT Total Impervious Area Contributing to Boy Scout Camp Road Pond (Phase 4) = 106,860 SOFT Tarawa Terrace 11 Phase 4 Impervious Area Draining North to Future Phase Ponds Quildings/Driveways; it iri # Units BuiOngiA ' ij Total Building r i r U' jotgl Driveway 1 3 3,200 9,600 1,200 3,600 11 0 3,300 0 1,600 0 III 2 3,200 6,400 1,300 2,600 V 5 4,300 21,500 1,420 7,100 VI 0 3,700 1 0 600 0 Building Area Phase 4 : 37,500 50-FT Driveway Area Phase 4 = 13,300 SOFT Name I Width Length (Fr) Area(SQ.-FT) I On -Street Parkin [Bougainville 1 28 375 10,500 0 fl Sidewalks: Tr ils.. Phase 4 Road Areas = 10,500 SQ-FT Phase 4 On -Street Parking = 0 SQ-FT Length: 1,100 FT width: 4 FT Phase 4 Sidewalk Area = 4,400 SQ-FT Length: 550 FT Width: 6 FT Phase 4 Trail Area = 3,300 SQ-FT Total Impervious Area Draining to Phase 5/6 Ponds (Phase 4) = 69,000 SO -FT Tarawa Terrace It Phase 5 Impervious Area Calculations BuildinasLQiiveways: Building Type.# Uniis i f W i it i Ar Iv w iv a 1 17 3,200 54,400 1,200 20,400 11 4 3,300 13,200 1,600 6,400 III 12 3,200 38,400 1,300 15,600 V 10 4,300 f 43,000 1,420 14,200 V1 22 3,700 1 81,400 800 17,600 Building Area Phase 5 = 230,400 50-FT Driveway Area Phase 5 = 74,200 SCE -FT } Roads: Name Width Length (FT) Area(SO.-FT) On-Streel Parkin Guam 34 1,901 64,634 0 Bougainville 28 991 27,748 0 Mews "F" 16 530 8;480 2,280 Alle "6" 16 254 4,064 0 Alley "7" 16 416 6,656 0 Road "H" 28 609 17,052 0 Road "G" 28 787 22,036 0 Load "F" 28 539 15,092 0 Alley"8" 16 510 8;:1.60 0 Tarawa Blvd 38 1,314 49,932 0 Sidewalks: Trails: Phase 5 Road Areas = Phase 5 On -Street Parking Length: 9,142 FT Width: 4 FT Phase 5 Sidewalk Area = Length: 4,468 FT Width-, 4 FT Phase 5 Trail Area = 223,854 SQ-FT 2,280 SO -FT 36,568 SO -FT 17,872 SO -FT Total Impervious Area -Phase 5 = 585,174 SO -FT - 0 . • Tarawa Terrace. II Phase 6 Impervious Area Calculations -ways: Quilging Type:' !1 EI i Area D{Yeway Area1Unit Total Oila=Wayz r 1 20 3,200 64,000 1,200 24,000 II 12 3,300 39,600 1,600 19,200 ill 22 3,200 70,400 1,300 28,600 V 15 4,300 64,500 1,420 21,300 VI 14 3,700 L51,800 1 800 11,200 Building Area Phase 6 = 290,300 SO -FT Driveway Area Phase 6 = 104,300 SO -FT Name Width Length (FT) Area SO: Fr) On-Strest Parkin Saipan 32 1,520 48,640 0 Road "1" 28 1,267 35,476 0 Alley "6" 16 436 6,976 0 Road "J" 28 431 12,068 0 Bou ainville 32 1,706 54,592 0 Mews "K" 20 510 10,200 21100 Mews "J" 20 472 9,440 2,100 Mews "1" 20 510 10,200 2,100 Mews "H" 20 708 14,160 2,100 20 455 9,100 2,100 m 16 273 4,368 0 16 875 14,000 0 Sidewalks: Trails: Phase 6 Road Areas = 229,220 SO -FT Phase 6 Qn-Street Parking = 10;500 SO -FT Length: 12,092 FT Width: 4 FT Phase 6 Sidewalk Area = 48,368 SO -FT Length: 3,364 FT Width: 4 FT Phase 6 Trail Area = 13,456 SOFT Total Impervious Area Phase 6 = 696,144 SOFT Project Narrative: Tarawa Terrace Phase 5 September 17, 2008 Phase 5 high density development of the "Tarawa "Terrace II neighborhood covers 34+ acres of land. The residential project includes demolition of 160 outdated, existing housing and construction of 64 new duplex buildings which will house 128 Marines and their families. Plans also call for construction of same new roads, utilities, and other infrastructure. Tarawa Terrace Il is located off Highway 24 in Onslow County near Jacksonville, North Carolina on Marine Corps Base Camp Lejeune. Stormwater runoff will be discharged in an Unnamed Tributary to Northeast creek which is classified as SC-HQW;NSW. Tarawa Terrace is within the White Oak River Basin. There are no bUffCr requirements, no new road construction to access the site, and no off site drainage for phase 5 of "Tarawa Terrace. Storm water runoff from the site drains to either the North Guam Drive or South Guam Drive detention ponds proposed within this phase. The two ponds stated above are part of the modification to Storm Water Permit No. SW8 051018. This permit includes the Boy Scout Camp Road pond and the Tarawa Boulevard Pond at the southwest corner of Tarawa Terrace Phase 2. The Tarawa Boulevard Pond was constructed as part of Phase of the development of the Tarawa Terrace 11 nciglib orliood, while the Boy Scout Camp Road Pond was constructed as part of Phase 2. Storm water runoff will be routed to these ponds through subsurface drainage. A small portion, approximately 24,348 ft'` total, of Phase 5 was unable to be routed to the detention pond due to existing conditions. About half of the area that is unable to be detained is because the existing road along the east side of Phase 5 has elevations lower or approximately the same as the SFIWT which will cause flooding in the street from the inlets overflowing. The area at the western portion of phase 5 that is unable to be detained has the same issue as discussed above. Refer to the Tarawa Terrace Drainage Area Map for area to bypass pond. Sediment and Erosion Control Measures for the 34+ disturbed acres and 37% impervious surface of phase 5 construction include silt fence along the perimeter of the site and three temporary sediment traps to remove sediment from the expected sheet flow. Rock check dams are also to be installed where flow has been channeli'red to assist in the removal of sediment. Drainage areas for the silt fence, temporary sediment traps, and check dams have been designed to North Carolina Department of Environment and Natural Resources (NCDENR) regulations. The sediment and erosion control plan for Tarawa Terrace Phase 5 were approved by NCDENR on August 18, 2008 under permit ID ONSLO-2009- 003. CEIVEID S E P 2 4 2008 BY: Project Narrative: "Tarawa Terrace Phase 6 September 17, 2008 Phase 6 high density development of the Tarawa Terrace II neighborhood covers 43-+- acres of land. The project includes demolition of outdated, existing housing and construction of 83 new duplex buildings which will house 166 Marines and their families. Plans also call for construction of some new roads, utilities, and other infrastructure. Tarawa Terrace II is located off Highway 24 in Onslow County near .Jacksonville, North Carolina on Marine Corps Base Camp Lejeune. Storrnwater runoff will be discharged in an Unnamed Tributary to Northeast creek which is classified as SC;HQW;NSW. Tarawa Terrace is within the White Oak River Basin. There are no buffer requirements, no new road construction to access the site, and no off site drainage for phase 6 of Tarawa Terrace. Storm water runoff 11•0111 the site drains to the detention pond located in the central area of this phase. The pond stated above is part of the modification to Storm Water Permit No. SW8 051018. This permit includes the Boy Scout Camp Road pond and the Tarawa Boulevard Pond at the southwest corner of Tarawa Terracc Phase 2. The Tarawa Boulevard Pond was constricted as part of Phase 1 of the development of the Tarawa Terrace ll neighborhood, while the Boy Scout Camp Road Pond was constructed as part ol'Phase 2. Storm water runoffwill be routed to these ponds through subsurface drainage. A small portion, approximately 12,582 ft', of Phase 6 was unable to be routed to the detention pond due to existing conditions. The existing road along Phase 6 has elevations lower than the SHWT which will cause flooding in the street from the inlets overflowing. Refer to the Tarawa Terrace Drainage Area Map for area to bypass pond. Sediment and Erosion Control Measures for 43+ disturbed acres and 38% impervious surface Phase 6 construction include silt fence along the perimeter of the site to remove sediment from the expected sheet flow as well as a rock check dams where flow has been channelized. Drainage areas for the silt fence, temporary sediment traps, and check dams have been designed to North Carolina Department of'Environment and Natural Resources (NCDENR) regulations. The sediment and erosion control plan for "Tarawa Terrace Phase 6 were approved by NCDENR on September 11, 2008 under permit ID ONSLO- 2009-026, 7VE BY: --``-f '! 1lT� Im TARAWA TERRACE 11 PHASES 5 & 6 STORMWATER CALCULATIONS AND SUPPLEMENT FORMS MODIFIED PERMIT SW8 051018 CAMP LEJEUNE, NORTH CAROLINA Prepared for: ATLANTIC MARINE CORPS COMMUNITIES, LLC C AR b 31 4 410-07 -- 11111110 Prepared by: OCT C 8 7nnR BY;61'ayo 51v_/� LITTLEJOHN ENGINEERING ASSOCIATES 1935 TWENTY-FIRST AVENUE SOUTH NASHVILLE, TENNESSEE 37212 OCTOBER 7, 2008 m Drainoee Area: 1'ennanem fool Depth = Pond Surface Area: Tarawa Terrace II Phase 5 North Pond OIf-SiteDrrinageArea— 0AC Taraxa Temee 11 Drainage Area - 29.4 AC 1'r+ral Uneimige'.Irru M.1 ,IC ImpmiousArea— 11.80 AC Percent Iruptninus - 42 , 7 I-r. POTUI IIDTTO111 Elev, - 6.0 SAIDA Ratio = Surlace Area Required = (R,17'1O1l00)*D,I = fatal Volume Provided (a[ 12.0) _ Find Pxacl Curresporidiug I'enuanenl fool Surface F.leration: Next Lower fond Con[our: l7 Next I I igher 11011d Contour. li Lower Comour Surfrce Area: 40,438 1 l igher C01110ar Surface Area: 48, 2S l rota Change in Surl;rce Area 7,913 Change per .01 Fr. 78 Required Surface Area 48,247 Increase Needcd to Meet the Requirement 7,807 'fetal Numtxr of Increments 101 Elevation Mecting Ilrc Surface Area Requirement 13.01 Curre:prorrrling 8,111' Elerurlurr Surface Area tiir 13.01 48,.125 48 24" SQ 1°T GUAM DRIVE, HOR'I'II POND LI,I:VA'I'ION (FT) SURFACEARP;A (SQ Ff) HLEV. VOLUML ICU Ff) CUNIIJf,A'flVl:-VOLUME (C) F-11 SURFACE AREA fAC) 6.00 0 0 4 0,00 7,00 0 0 0 009 7,75 0 0 0 0.00 8.00 26,808 2.234 2,234 0,62 9.O0 1 30.034 28.406 30,640 0,69 10,00 33,384 31,694 62,334 0.77 1 Loo 36,861) 35.108 97.442 0.85 12.00 40,438 38.635 136,077 0.93 12,50 41,593 20,507 156-584 0.95 13.00 49.251 22,440 179,024 1.11 13.50 56,501 26,161 205,185 1,30 IA,OfI 60.510 29.249 234,434 k.39 15.00 66,123 6.1,29') 297,733 1,52 16,00 71,367 68,728 366,461 1 1,64 So rrar.r. Area at I;.t) =; 48,251 NO-FI' Vnhunr fit he Cnu[rnlltd: Volume (V) = Design Rainfall • R_v • Dmsnage Area R_v = 0.05 t 0.009 * 1 R v= Dcsign Rainfall- 1.5-IN V - (15-IN)' 0.464 INIIN * 1 1,11121N • 28.4 AC 1'- 1.51 651.7is C&=177' 211,5x2 CV-1'1' Littlejohn Engineering Associates Page 1 of 2 I — Perccut hnlxrvious 0.42 IN11N 1,237,104 S'Q-17 514,008 SQ-F'r IQtf9lS11Eli1ffirli!d IMMMCZ it 3.9 (From NC DENR 6NIP Manual SAIDA Ratios for Coastal Counlies} 1.11 .rC 48,217 SQ-F7' Volume Pruridref for Perimmenr 1'md OK I'uluun, Required_fr '1'rn+parurr Paul V,dimse Require d Jor 7ie++purar v I I IPilh Perinam 'I I'ohonje,irernurlyd Fur (fmur 13. 00 F7:) 10/712008 Tarawa Terrace II Phase 5 North Pond Find Exact Currespuud ingTenrporan Von Surface EIUVaI inn: Next Sower fond Contour: Next Ifigher Pond Contour: bower Contour Vo line: I4ighcr Curdour Volume: Tohd C11angc in Surhice Arcs Change per .01 Ft. Required Vnlumc Increase Needed to Mccl the Requirerncat 'i'oud Number ul'Incremcnts Eilmilion Meeting the Volume Requircmenl Volume (a, 14.24 Dra'do"n'I'inlc C'ahcnlntiom: Temporary Pont Depth: Target Dnmdou it - ? - 5 Ugcs (hsflce Equation - 15.90 16.00 297.731 3h6,461 6R, 728 6 A 7 244.592 -53.150 -76.33 14.24 Cf-egm erling Tepuporary M I E&, rnriun 245,269 244,582 CI�T CUA\1 6RI1'B NORTH POND STAGE-STOWACP, TAHI,F, IiL$VA'17ON W I SURFACIiAR17A (SQ F'1') FLIiV.VOLUMFCUMULATIVL-VOt.UA1F (CU FI') (Ctl iT) SURFACHARFA (AC) 6.00 0 0 0 0.00 7.00 0 0 0 0.00 7.75 0 0 0 0.00 8.00 26,808 2,234 2,234 0.62 9.00 30,034 28,400 1 30.640 0.69 10.00 33,394 31,694 62„334 0.77 11.00 36.860 35,108 97,442 0.85 i2.00 40,439 38,635 136,077 093 12.50 41,59.1 20,507 T55,584 0.95 13.00 48.251 22,440 179,024 1.11 13.50 56,501 26,161 205.185 1.30 14,00 60.516 29,249 2.14,434 I.J9 II ,29) 297.733 2 G5.02 00 71,.3671 6 L1.G54878 ORI171CI7 Size (in} 2.5 ORIFICF:SiLe6n) 3 ORWICE Siza (m) .1.5 ORIPICF, Size (in) 4 14.24- 13 - 1.24 171' Q=C_d i A' {2'gih13)^ill A R h= Q= 1gQ A - 11= Q_ V�Q 1) 11 = A116 Qa VrQ = 0.8 (0) 34 SQ47' 1.132 0, 13 Cl'S 497,559 SECONDS 5.64 DAYS 0.044 SQ.h7' 1.112 0.19 CFS 341.740 SFCONDS 3.96 DAYS 1. ilvl '53. 1 SECONDR 2.93 DAi's 0 08 7 SQ • h'T Lo7o 0.33 CFS 195,936 SECONDS 2.27 DAN'S OK Littlejohn Engineering Associates Page 2 of 2 10/712008 00 oao x�- oaaaaa���o a� I ro U A LL Lq�p u a yGl � } i �I pp a •C y ri .- ri Q 7 i vi � O pp pp pp pp ..1 pan nco a,o--r-, ri .- DraimkL, A rya: Ppznnucnl Pool Uepth = I'oud Su rfnee Area: Tarawa Terrace II Phase 5 South Pond 011-Silo Drainage Arca - 0 AC Tamea'Terrace II Drainage Area= 14.9 AC 7ornl 0rninnge Area = 14.9 AC Impo rims Area 566 m Percent Inrpen inus = 38 'Y., 7.00 I''I'. Pond 11a1tom Eles.= I U SA/DA. Ratio Surface Area Required= (AJ 110110i11"0.f _ Total Volume Prm ided (at 18.0) = Rind ICsart Corresponding Pennnuent fool Surface F.Ievar ion: Ness Lmer Fond Contour: 17 Nest Higher fend Contour; 19 Lc;n cr Contnur Surface Area: 27,184 Higher Contour Surface Area: 42.810 Total Change in Sur 1i£ee Area 15.626 Change per .01 FT. 156 Required Surface Area 16.339 Increase Needed to Meet the Requirement -845 Total Numberoflncrements -4 Elcratiuu Nlecting Iho SULIku Arca Requiremew M.96 Curre�punding 1761!' l:levurlarr Surface Area Cu 16.96 16,.195.47 CUAM DRIVE SO(PE'II POND S'D',IGEi S'I'OItACr'1',1111,F, 650 351 SQ-F'T 246,560 SO-F7' Permanent Pool Iaev. = 18.0 4.05 (From NC DI:NR DNIP Manual SAMA Ratios for Coastal Counties) 11,60 lie - 26.339 .SQ-FT 11X,„4F ('f`-F1' Yuhune Prorided1i/r Yermunenr Puul 4C1-f 1US [.I.EVA1 ION (PT) SURFACE AREA (SQ FT) IEI.EV. VOLUNIE DCU FCI CUNII)[.A'I'IVE-VOLUMI. (CU Ff) SURFACE AREA 1AC 11.00 0 0 0 0.00 12.75 0 0 0 0.00 13.00 16,713 1,393 093 0.38 14.00 19,159 17.922 19,315 0.44 15 00 1 21.715 20.424 39,739 OSU 1600 24.393 23.041 62.780 0.56 17.00 27,194 25,776 89,555 0.62 1750 28.632 13?52 102.508 0.66 18.00 34.491 15.759 118,266 0.79 18.50 40,559 19.742 137,008 0.93 19,00 42.810 20.940 157.949 0.99 2010 ;6.552 44.G68 21}251G 1.07 20.90 49_22 42,GS6 245,162 1.11 ..In'r:£" Are:£:£r 18.e 1'f. 34,401 .VQ-f'7' � Vulmne In be ('line ndled: Volume (1r) = Design Rainfall + R_r • Drainage Area R s--0.05+0.00°)"1 R V- Design Rainfall - 1 S-IN V ={ 15-IN)' 0.464 1WIN ` I P'I'1121N • 18.55 AC. I'- 0.73 ACV[' 11.8U.1 (: U47 15si"10 Cf'-Jr 7 16, eJ9 S& F.T Uh' I - Perceril Imperious = 0,39 I NII N Volume Required,j£r 7rmporary 1'-d VW, Required firr 7i'mp, Paul Wilb pemumenr Follow Armor For (Imm A.94 FT) Page 1 of 2 Littlejohn Engineering Associates 101712008 Tarawa Terrace II Phase 5 South Pond Find Corrrspouding TCIII pnra n' Pmul Su r[aer 1S1c+al inn \est 1-ou ei fond Contour: Nest Th,,1ier frond Contour: Lotter Contour Volume: Iffglicr Contour Volume: 'Total Change in Surface Area Change per .01 FI. Required Volume hicrcase Needed to \Seel the Requirement Total Nutnbu orincrements Eilcr alion Meeting the Volume Requirement Volume (cl 18.84 Dra rsdue 11'1'imr C:druhntions: Tcmporar) Pool Drpth: 7iirger 2 - 5 Daps Orifice Fqualion 19.00 20.00 157,848 -'02,516 44,668 447 150.069 -7,779 -16.42 18.81 Cnrrrsnnrrdirrh Trngnrnrl' h-1 Elernliwt 5r{s15 1 IS11,669 r_'IL17 GUAR\I DRIVE SOU I'll POND STAGE -STORAGE. FABLE EI.EVA'I'ION 070 SURFACi? AKFA IS Q F'I') ELEV. VOLUMIT ICU FT CUMU1-ATIVE VOIAMI: ICU F?' SURFACE ARGA fAC) 11.00 0 0 0 0,00 12.75 0 0 0 000 I3.00 16,713 1,393 1.393 0,39 14.00 19,159 17,922 19,315 0,44 15.00 21.715 2M24 39.739 0.50 I6.00 24.393 23.04I 62.790 056 17.00 27,184 25,776 89,555 0.62 17.50 28,632 13,952 102,508 066 18,00 34.491 15.758 119.266 0.79 18,50 40,559 18.742 137.008 0.93 19.00 42.810 20,840 157,849 0.98 20.00 -1G.5" 1d.668 202516 1.07 2010 48,22^_ 42.646 245.152 1.11 ORIFICE Size (in) 1.75 ORIFICE Size (in) 2 tIItIFIC1'. Sirc iu:I `_5 ORIHCESize (in) 3 ORIFICE Size (in) 35 ORWICli Si>c (iu) 4 19.0 - I8,0 - 1.00 fT Q = C_I . A • Wg•h13)^ I12 Cd= :I = !r = Q= V/Q it - Q h- Q- Vx? .a - h= Q= ViQ = h= Q= V7Q = 0.8 0.017 SQ-F7' 0.927 0-06 CFS 533r192 SECONDS 6.17 DAPS 0.022 SQ-FT 0 917 0.08 C1'S 410,761) SECONDS 4.75 DAPS 0.11,31 S'r-, 7' ff,.Ylr: 1:Fs 205,932 SL(`t.rNl)S 0,04V SQ-!7 0,N75 0.17 US 196,860 SECONDS 2.16 DAYS 0,067 SQ-PT f1854 0.23 CI S 1.18,949 SECONDS 1.61 PAYS 0AN7 SQ-FT A.,Y 13 0.30 CFS 1073115 SECONDS 1.'_5 DAYS 0K Page 2 of 2 Littlejohn Engineering Associates 10/712008 LU -i m H LU C7 0 ILU V a Z 0 (L H 0 i) LO LU a LiJ H a a a O O C O O O O O O — T ] � � V d lL .D Io CD O rn Pd", M � obi ^ N N N M D � oh0000blnIL— w It m V'` P P M h— v� O rl O M a0 r• — �O— x O b b b b b b -- - (its. •O W 00 't 00 M a � L a rl p Ga Q N 'n M M �4 w41I,�oo-a:oo xrn h'nh x� a, o ri 'nry rJ CY r:r•;h rs�nx 'nN � r N •--' N rl rJ V V V V 0 �-' N M �7 'n �O l� h 00 00 Ol. N O W — — — [1 y w u _ ry x� '.ti P O 0 0 0 0 ,O 0 h 0— o 0 0 0 0 1 RJ r K 'C i T ? p u 0 i oa h x rJ 'n a V' 7. It LU im xC, 00— n ==riririv p xr�hc�ry h K e n ti C .F Q�Q0000�o 'n 0 0 0 0 0 0 0 ^ N M 'n O h roc SEP 2 4 ?OQ8 Draitinye Area; Pennanent fool Depth - fund Snrfaee Arca: SAIDA Ratio Tarawa Terrace II Phase 6 Pond Ofl-S 9e llm b,agc Area= 0 AC PTatnaee Area = 39,4 AC Tolal 1)...mrgc ,b- 39.-1 11C Iutpervious Area 14, 61 AC 11cr'cent Ingrers'ious = 38 '%. 7.5 FI'. Pond Ilottorn Fiev, = 75 SurflccArca Required = (R,iT10110n)"IM = 'I'Oil I Valrrrrll' Provided (at 15,0) = Fiud Fnart Corresponding Verrn:rlrr'Irl Pout Surface Eive alion: Next Lower food Contour: Next I Iigher Pond Contour: Lower Contour Surface Arra: Higher Contour Surface Area: 'rolal Change in Surface Area Change per .01 1T. Required Surface Area Increase Needed to ivlect the Requirement Total Numbcr of Inurmcnls elevation \letting the Surface Area Requiremenl Surface Area Cm 14.05 1,71e; 64 SQ-FT 645.089 S2-17 Pennanenl POaI iilcv. - 15.0 3.3 (From NC DF-NR I1\IP Manual SAIDA Ratios for Coastal Counties) 1,32,IC - 57,323 SQ-1,-7- 245,491 (lLri' I'ultmw Prurided Jirr Perrmuaenr PuuI 1400 16.00 56,520 78.431 21,911 219 57,323 803 5 14,05 Cir ,cp-mfing 13,111' lilrrrrlim, 7,541.3.. 57,123 A'L)-FT 1'IIASE:6 POND STAG.V-STORAGE,, I'A 131,); ELEVATION (FI) SURFACE AREA IS Q 17'1') ELEV, VOLUML WU F0 CUMM A'I'IVt VO1JJMF ICU 17-r) 3UR1:AC1i AREA IACI 7.50 0 0 0 000 9.38 0 0 0 0.00 10.00 42,059 8.762 8,762 0.Q7 11.00 45.449 43,743 52,505 Url 12.00 49.020 47.22.1 99,729 1.13 13.00 52.724 50.861 i50.589 1.21 14.00 56.520 54.611 205.200 1.30 14.50 58.495 28.752 233,953 1.34 15.0U 66,137 31,138 265.091 1.52 15,50 72.284 34.594 299.685 1.66 16.00 78,43$ 37,669 337353 1,90 17,00 85,672 92,025 419,178 L97 18X) 94,5GG 90,062 509,461 2.17 19.00 ID0.942 97.737 607,197 2.32 Surface Arco at 15,11 = 4037 SU4.-7. Volume to 1w Cnulrullcrl: Volume (V)- Desipi Rainfall • R_v + Drainage Area R v e 0,65+0.009*1 u v- Design R[iiurall= I,5-IN V - (1.5-1N) • 0.454 MIN • I F1'I121N • 39.4 AC I' 1,91 AC FT Cl FT .i%,32.? AO -IT (W I - Percelll IllgmNieus = 38 0.39 IN11N Vulume Rcquired ir,v 7e'rupnar.l• foul Toluene Required Ji+r Ternlrurmy Pour 1f7Nr Perim ent Vnluau•,lernugpa! Fur (in- IS. 0 FT) Littlejohn Engineering Associates Page 1 of 2 1017/2008 Tarawa Terrace II Phase 6 Pond Mud Exacl Corresponding'1'enlpnrar) fool Surlace Elve ;anon Next Lowel1'Iald C0111OUT: 16.00 Next I ligher fond Contour. 17.60 1-0u er Conivur Volume: 337,353 Ilig,her Cnmuur Vnlumc: 419,37N total Challg'e 111 Vu lu1nC 82.025 Changeper.ol Ft. 830 Recpnred V01111114 W NO Increase Needed to Alcci the Requirement 11.037 Toull Num" of increm, tms I4,4f, Hluvatiun Meeting the Volume Requirouent M.14 Correyanding Temporurr I6a,! Efewithm Volume(u! )6.14 35i,297-55 > 349.391) r'!�-Fi PHASE. 6POND STAC;I S'I'ORACETARLE Drawdomi Time C'alcldatiuns: Temporary Pool Depth; Torgrr Draledouvl - i - 5 DaYs Orifice Equatinel - 171.1iVA'I'ION SURFACE AREA EIA V. VOI.IJ%1F, Cl1h1l1LA'i'1VIi-�'OI,IIyIli:SURFACli AREA fF"['] ISQ FT I ICU FF) (C1f FT l (AC) J 7.50 0 0 O 0,06 9.38 0 0 0 0.00 10,00 42,059 8,762 R,762 097 11:00 45.449 43,74.1 51505 1 04 12.00 49,020 47,223 99329 1.13 13.00 52.724 50.861 150,589 1.21 1 Uy) 50,520 54,61 1 205,200 1.30 14.50 1 59,495 29,752 233,953 1.34 15.00 66.1.17 .11.139 205.001 1.52 15.50 72.284 34.594 299.685 1.66 16,00 79,431 37,668 337.353 1.80 17,60 85.672 92.025 419,37E 197 ISMO 94,566 110,082 509.461 2.17 1900, 1001142 97.737 607.197 2.32 ORIFICE:Size (in) 3 ORIFICE Size (in) 3.5 ORIFICr Size lin) 4 ORIFICE Size (in) 5 16.14-15.0= 1,14 F'1. Q a C_d • A • (2•g•(10))^ I12 Cd= 0k 0.Od9 SQ-1"1' 1.020 (.18 CPS 453,411 SECONDS 5.25 DAYS 0.067 SQ-FT U.999 0.25 CI'S 336.575 SECONDS 3.90 DAYS rd'17h O : ` C 7S _•f7,4 _'t Si'.0)m1 3.01 IM VS 1) 136 SQ-1-T n, 9.;6 0.49 CFS 170,338 SECONDS 1.97 DAPS OK Littlejohn Engineering Associates Page 2 of 2 1C11712008 LU J m a W CD a 0 I-- W a V/ n z 0 a to W U a W H a a F- x iU O O n O rl v, oc G1 �o E r 0 0 0 0 0 0 0 0 0 i � p pIn C re) n �0ri M rr^ N a U s i N M1 DO a� O n In In M DO N �d n Sao- ri,n EIn U i O O C1 n et 00 O a. N In n o n 12, n N rn R� Ln 000po ri ri E rlo v N 'n VM v,.o ,a ' r 'oa+v,rn n O ,nt- vl DO <t 000rnrnon �: ^NNrIM� n U i a [y V1 h D7 n c 7 O O -- C1 7, M vi rl op M C O ,n o ,n r1 .p o� d V n oo o n ri a M ri o l� i� a a u 1 s. "% '? a, -. o, 'o a U C C n M oo ,n C ,n rl 7 'o In O ^ � ,n o 'n C- -n 4 x :n i 0 �n M V"t O M1 oo Cr ?i w wW 0 0 n V' M^ O 7 N D o n n N a` O ^ N rn ^ C, O - �OU ri a "� oo a' „o "110a,.n-o c i j ^ hl f,! rl Cl tt Vn iD � U �, N 00 �f 00 -n n 00 ,D r, M1- in B O GO 00 O l� o 4 c,5 r-: ri o r C W ,n In N M M M DO a, a` O a w m � 0 s �C a` cT O Q O ri i O O O cT O n ,n �t -: N� ,O ,n (-I In ri'.o ao'4Dri oo ll; 4o t� x �t In v) ,n .o n 1-00 a+ i D _ v-1 - - - a; 5 EP 2 4 26op grMACTEC engineering and constructing a better tomorrow 27 August 2008 Mr. "Thomas J. Davis, P.E-. Littlejohn Engineering Associates 1935 Twenty -First Avenue, Socrtll Nashville;, TN 37212 SubJect: Seasonal High Water'i'uble Evaination Taramil Terrace, Section 5 and G Camp Lejeune, Nurtfl Carolina MACTEC Project 6470-08-2196 Dear Mr. Davis; MACTEC C E ngineuring nod Ccrosulting, Inc. (MAC 1---'Q is pleased to suhmit this report concerning the prelinlinaary .soil evaaluaation of proposed siormwater detention ponds within the TarawaTerrace, Section 5 Mid 0 11 Canlp L,ejeunc, North Carolina(projQct site). 'This report address the scope of services detailed in MAC'TEC's proposal 08-IZAL-335 dated August 21, 2008. The report documents the methodology used to asses the approximate depth to a seasonal Nigh water table (SHWT). Background and Niettlodology The project site is located within the "Tarawa 'Terrace housing complex oil Marine: Corps Base Camp I- jel.rile, Onslow County, North Catrolina. "The areas evaluated are located on the east and west side of Tarawa Boulevard north of the intersection of Tarawa Bnulcvar'd atnd Guam Drive. The project site is a ulilitaa-y housing complex that is under going redevelopment, MACTEC soil scientist conducted a preliminary evaluation a1' the soils within thrcc areas proposed for stormwater retention ponds on 25 August 2009. Three; hand -auger hurings were; aclvariced at pre- determined boring locations. This evalua€ion included field descriptions for soil textsare; color, structure; and the approximate depth to SFIWT if possible. The SHWT depth was based on soil characteristics through identification of low chroma redoxinlot'phic features (mottles). All clepths presented are below the land surface. Findillg,'s The soils in the vicinity of the areas evaluated within the project site are mapped as Baymeaade fine sand ancf craven Fine sandy loam soil series according to the Soil ,Survey (lf Onslokv Comar, Almrth Caiwlirtra (USDA 1992), The soil boring at. Boring I revealed soils generally similar to the Bayrlieade soil sc;rics. The soil boring at Boring 2 revealed soil than appeared to be previously placed fill nratc:rial ors top of soil aNIACTEC t?uginecrhtg u aat Cwisutfiug, Inc. RECIF,1 33tf1 Alhintic AVe;naal: • Raleigh, NC 27&0-4 •['hone: 919.876,0416 • Fax: 919.8:ik.813(, SEP 2 4 2008 corn Torairn Terrace, ,Serlirm J ours G ho.jecl tVr;.: 0 7{)4W-2/96 Seoxoual high Waia -Table l;vahmrlon 27A ngusr 20X0,1 011.4mv Cormrli', Norlh f:m'olrn« Page 2. generally similar to the fviuckalce loan} Soil sc,rics. The soil boring at Borim, 3 1.0vo.,11 l soils getlerally Simi€ar to the Craven soil series. The Baymeadc fine Sand soil seric,s consists of well (,rimed soils on low ridges and convex uplands. These sails For'nied in ccxa'sc textured scclimcnt.s with slopes ranging from O to Cl perccnt. The Cravcsl fine sandy loath soils consists of moderately well c1m m,:d soils on npl;ulcls near large clraisegeways and on short side slopes. 'these soils formed ill fine textnrcd marine sediments with slopes rangim from 4 to 8 porcent. Included within this soil slapping unit are small areas of Nluckalcc soils in narrow drainagcways. The Muckalee loan, soils consist of poorly drafoted soils on floodplains. These soils forrlled in moderately coal -se textln'ed recent alluviurlt with itcru'ly level slopes. "These soils may bu folmd ns inclusions in ,mils mapped ;ls the Craven soil series. "rile SHWT depth was based oil soil characteristics througlh identification of low chrorna mottles. The low chroma rioules ,suggest past C01)(H io)ls of saturation and reducing soil conditions. Evidence of a SHWT was ohservcd from 24 inches to 38 inches below the cxi.stim, land .surface in tic areas evaluated. Evidence of a SHWT was observed at 38" in Boring 1, 24" in Boring 2 and 26' in F3oring 3. Observations Soil Boring 1 — Back slope 4-6% A 1 0-4" Fine sandy loam, granular, very friable, nose sticky, non plastic, 10YR 4/2 a A2 4-8" Fine sanely loam, granular, very friable, non sticky, non plastic, I OYR 5/4 o E 8-18" Loamy f me sane,, granular, very friable, non sticky, non plastic, I OYR 6/2 ® Bt 1 18-38" Sandy loath, gramdar, very friable, non sticky, non plashe, IOYR 4/4 with I OYR 5/4 mottles 0 13t2 38-45" Sandy clay loans, weak fine suhangular, friable sticky, plastic, 2.5Y 5/4 with I OYR 6/2 and l OYR 5/8 mottles 13Cg/Cg 45-60" Sandy clay loam, massive, friable, sticky, plastic, IOYR 6/2 with 5YR 4/6 mottles n SHWT observed at 38". saturation and free water greater than 60" Soil Bnrin;7 2 —Fool .slope; 2-41/r, o FI 0-8" Finc sanely loam, granular, very friable, non sticky, non plastic, IOYR 3/2 ® F2 8-14" Dine sandy loam, granular, very friable, non sticky, non plastic, 2.5Y 5/4 0 F3 14-24" Sandy ,oast, granular, very friable, lion sticky, non plastic, mixed I OYR 5/4 and 2.5Y 5/3 with 10YI2 5/8 mottles O A 24-36" Native Iilticky loam, granular, friable, non sticky, non plastic, 10YR 2/1 O Cg 36-60" Loamy fine sand, granular, very friable, non sticky, non plastic, 2,5Y 6/2 • SHWTobserved at 24", the depth where native soil wits csticountered, saturation and free water observed at 30" and 34" respectively o First 24" of soil appeared to he old C11 material over native, llydric soils RFCFJNTFD SEP 2 4 2008 BY: _ Tarawa Terrace, .Section 5 and (i Sumonal 11(gh Maer 7M)le Evrrhrrmon Onslow cou nv, Nor717 Carolina Soil Boring 3 — Back slope 4-6% AIACTGC Projvrt No.: 0470-08-2196 27Augtcsr 2008 Page 3 • Al 0-5" Fine sandy loam, granular, very Friable, non sticky, iron plastic, 2.5Y 513 • A2 5-10" Fine sanely loam, granular, very friable, non sticky, non plastic, 2.5Y 5/4 • Bi l 10-26" Clay loans, weak fine suhangular blocky, firm, sticky, plastic, 10YR 5/4 with 7.5YR 5/6 mottic;s • Bl2 26-,;{}„Clay, rrrassivc, very fir€tr, v€sry sticky, very plastic, 10YR 516 with 10YR 6/2 and 5YR 5/6 mottles • BO 36-54" Clay, massive, very firm, very sticky, very plastic, 10YR 5/4 with 2.5Y 6/1 and 5YR 4/6 mottles; at€ger refusal on a root at 54" • SHWTobscrvc d at 26", tit€tnration and free water greater than 54" Surn1narY IMACTI C has completed a preliminary evaluation of the soils within three areas proposed for slormwater retention ponds within Tarawa 'Terrace, Section 5 and 6 at Camp Lejeune, North Carolina. The evaluation included determining approximate depths to the SHWT at three locations delcrmined by the client. Evidence of a SI-1W'T was ohscrvvcl from 24 inches to 38 inches Below the existing land surft€ce in the areas evaluated. Evidence of it S1IWT was observed at 38" in Boring 1, 24" in Boring 2 and 26" in Boring 3. This report is intended for the use, of I, ittlejohn Engineering Associates subject to contrtretual tertris between Littlejohn Bilgincering Associates and MAC1'EEC. Reliance on this document by any other party is prohibited without the exfVOSsecl, written consent of MACIT C. Use: of this report for purposes beyond those reasonably intencled by Littlejohn Engineering Associates and MACTR.' will he at the stile risk of tltc user. Closing We appreciate tyre Opportunity to conduct these environmental services to Littlejohn Hngineering Associates. Please contact Josh Witherspoon at (919) 831-8015 if YOU have any questions regarding this report. Sincerely, 1bIACT1 C ENGINEERING AND CONSULTING, INC. J(J—,At Witherspoon, LSS Senior Scientist IZC; I-l/J W W/jww i 91a t i m ima I -* ,rarau;, Tc,nux•Cr'ar,w,i'&•rt.gw u-iI ar,l,dnc ��14 Apl�ioav;f� Richard G. I-larmon, P.W.S. Principal Scientist Project Narrative: Tarawa Terrace II The proposed project plans call for the redevelopment of the Tarawa Terrace 11 neighborhood. Located off of Highway 24 near Jacksonville, North Carolina, the existing 'Tarawa Terrace 11 neighborhood is made up of houses constructed during the 1940's. This project calls for demolition of 817 existing units to be replaced by 389 duplex buildings (778 units). Existing roads will be repaved and reused for the redeveloped neighborhood. Demolition and construction is to be undertaken in six phases with one phase beginning upon completion of the previous phase. Water quality requirements are to be satisfied using wet detention basins. Currently an existing r"et detention pond can be found at the southern edge of the project boundary. This pond is permitted as the Phase III Pond for Tarawa Terrace I and is presently designed to handle runoff from the Tarawa•Terrace I neighborhood as well a small portion of the Tarawa Terrace 11 project area. Redevelopment plans call for this pond to be removed from its current project and to be included in the Tarawa Terrace 11 moiect. In the reddevelopment, the old III Pond will be referred to as the Tarawa Boulevard Pond. The pond will continue to handle the ninoff from Tarawa Terrace I for which it was originally designed. This off -site drainage amounts to approximately 29 acres with ✓ 40% impervious areas. In addition, new impervious areas to be constructed in Tarawa Terrace I I will be routed to the Tarawa Boulevard Pond. The pond will receive drainage from Phases I, 3, and 4 of Tarawa Terrace 11 as well as drainage from Tarawa Terrace I to be considered "off -site" for the purpose of permitting. To the east of the neighborhood, a second wet detention basin is planned. This basin shall be referred to as the Boy Scout Camp Road Pond and will receive drainage from Phases 2, 3, and 4 of Tarawa Terrace 11. As the project will be reducing the density of the neighborhood and shall be considered redevelopment, a small amount of drainage will be allowed to drain off -site where it is unpractical to route it to a pond. Low-lying cul-de-sacs where it would be unrealistic to route the runoff out of the cul-de-sac such as Hungnam Place and Tulagi Place will maintain existing drainage patterns and route runoff into wooded and well -grassed areas in such a manner as to promote infiltration into well -draining soils which are characteristic of this project. Wet detention basin locations and designs have not yet been finalized for Phases Sand 6 as well as for portions of Phase 2 and Phase 4. Drainage area and impervious area estimates will be included in the Stannwater Permit Application and shown as future phases. j .I DETENTION POND ANALYSIS FILE NAME: G:\DATA\WPDATA\WQS\POND1051018-1.WK1 PROJECT#: SW8 051018-1 REVIEWER: P.Bartlett PROJECT NAME: Tarawa Terrace 11 Tar.Blvd.Pond: Ph 1, 3, 4 DATE:. 22-Nov-05 Receiving Stream: Northeast Creek Class: SC HOW NSW Drainage Basin: White Oak Index No. 19-16-(3.5) Site Area 202.00 acres Drainage Area square feet Area = 80.85 acres IMPERVIOUS AREAS Rational C OS Bldgs 439900.00 square feet 0.95 OS Streets 297390.00 square feet 0.95 OS pkg/drives 150660-00 square feet 0.95 OS sidewalks 68168.00 square feet 0.95 OS other 13957.00 square feet 0.95 OFFS (Tar.Terr.1) 503031-00 square feet 0.95 TOTAL J. 7.,10 00:squ are feet Rational Cc= 0.51 SURFACE AREA CALCULATION % IMPERVIOUS 41.83% SA/DA Ratio 2.93% Des. Depth 5.4 Req. SA 103117 sf TSS: 90 Prov. SA sf VOLUME CALCULATION * place a "11" in the box if Rational is used Rational ?* FOREBAY Des. Storm inches Perm. Pool Volume= 555343 Rv= 0.43 Req. Forebay Volume= 111068.6 Bottom 6 msl Provided Volume= 121175.00 Perm. Pool msl Percent= Design Pool 12,6 msl Design SA 136807 sf Req. Volume iii1i157 cf SA @ = 79496 130181 136807 Prov. Volume i747672:': cf Elevation- 6 11.4 12.60 vs. 159,439 cf proposed ORIFICE CALCULATION Avg. Head = 0.48 ft Q2 Area = 31.43 sq. in. Flow Q2, cfs 0.724 cfs Q5 Area = 12.57 sq. in. Flow Q5, cfs 0.290 cfs Orifice Area 28.27 sq. in. No. of Orifices i1i Q= 0.652 cfs in x Diameter, inches weir H x W in Drawdown days COMMENTS Surface Area , Volume and Orifice are within Design Guideline,, DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1051018-2.WK1 PROJECT #: SW8 051018-2 REVIEWER: P.Bartlett PROJECT NAME: Tarawa Terrace it Boy Scout Camp Rd.Pond,Ph2 DATE: 22-Nov-05 Receiving Stream: Northeast Creek Class: SC HQW NSW Drainage Basin: White Oak index No. 19-16-(3.5) Site Area 202.00 acres Drainage Area ;::16 0 3 square feet Area = IMPERVIOUS AREAS 37.60 acres Rational C OS Bldgs 304350.00 square feet 0.95 OS Streets 193082.00 square feet 0.95 OS pkgldrives 101420.00 square feet 0.95 j Llt� OS sidewalks 44600.00 square feet 0.95 OS other 43611,00 square feet 0.95 square feet TOTAL i'67063Q} square feet Rational Cc= 0.51 SURFACE AREA CALCULATION % IMPERVIOUS 41.95% Des. Depth 5 TSS: 90 SAIDA Ratio 2.94% Req. SA 48094 sf Prov. SA €51$' sf VOLUME CALCULATION * place a "1" in the box if Rational is used Rational ?* FOREBAY Des. Storm i::f3€ inches Perm. Pool Volume= 158557 Rv= 0.43 Req. Forebay Volume= 31711.4 Bottom 4.5 msl Provided Volume= 38442.00 Perm. Pool 9 5f:. msl Percent=4w2°of Design Pool 10.54 msl Design SA 57548 sf Req. Volume ''85i cf SA @ = 30216 59831 57548 Prov. Volume €':599fi3. cf Elevation= 4.5 9.5 10.54 vs. 58,690 cf proposed ORIFICE CALCULATION Avg. Head = 0.44 ft Q2 Area = 15.28 sq. in. Flow Q2, cfs 0.338 cfs Q5 Area = 6.11 sq. in. Flow Q5, cfs 0.135 cfs Orifice Area 12.57 sq. in. No. of Orifices i'1 Q= 0.278 cfs m a Di eter inches iQ` weir H x W in x in Drawdown = days COMMENTS Surface Area , Volume and Orifice are within Design Guideline<_ STATE OF NORTH CAROLINA Department of Environmental Quality 127 Cardinal Drive Extension Wilmington, North Carolina 28405 (910) 796-7215 PILE ACCESS RECORD Q ?J DEQ SECTION: r' REVIEW TIME / DATE: NAME: _ -::5�G if n I t EMAIL: REPRESENTING: ��c�s r- PHONE: 4W ���_ Guidelines for Access: The staff of Wilmington Regional Office is dedicated to making public records in our custody readily available to the public for review and copying. We. also have the responsibility to the public to safeguard these records and to carry out our day-to-day program obligations. Please read carefully the following guidelines signing the form: Due to the large public demand for file access, we. request that you call at least a day in advance to schedule an appointment to review the files. 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