Loading...
HomeMy WebLinkAboutSW8950701_HISTORICAL FILE_19980922STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 g50-1 U 1 DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS KI HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE 1c1q 8 01 ►22 YYYYMMDD State ofNorth Carolina Department of Environment and Natural Resources Wilmington Regional Office James B. Hunt, Jr., Governor Wayne McDevitt, Secretary Division of Water Quality September 22, 1998 Mr. Ken Gebert, President Colony Coast Contractors, Inc., General Partner in Parkstone Limited Partnership 610 Gunston Lane Wilmington, NC 28405 Subject: Dear Mr. Gebert: NCDENR NORTR CAROLINA DEPARTMENT or ENVIRONMENT AND NATURAL RESOURCES Permit No. SW8950701 Modification Parkstone at Landfall High Density Subdivision Stormwater Project New Hanover County The Wilmington Regional Office received the modification to the Stormwater Management Permit Application for Parkstone at Landfall on April 29, 1998, with final information on July 16, 1998. Staff review of the plans and specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth in Title 15A NCAC 2H.1000. We are forwarding Permit No. SW8 950701 Modification, dated September 22, 1998, for the construction of the project, Parkstone at Landfall. This permit shall be effective from the date of issuance until September 22, 2008, and shall be subject to the conditions and limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit. Failure to establish an adequate system for operation and maintenance of the stormwater management system will result in future compliance problems. Ifany parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 2761 1-7447. Unless such demands are made this permit shall be final and binding. If you have any questions, or need additional information concerning this matter, please contact Linda Lewis, or me at (910) 395-3900. Sincerely, RSS/arl cc: Rick Shiver Water Quality Regional Supervisor S:\WQS\STORM WAT\PERMIT\950701.SEP Mark Ashness, P.E. Tony Roberts, New Hanover County Inspections Beth Easley, New Hanover County Engineering Linda Lewis Wilmington Regional Office Central Files 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone 910-395-3900 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer 50% recycled/10°/ post -consumer paper State Stormwater Management Systems Permit No. SW8 95070I Modification STATE OF NORTH CAROLINA ... DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WATER QUALITY STATE STORMWATER MANAGEMENT PERMIT HIGH DENSITY DEVELOPMENT In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other applicable Laws, Rules, and Regulations PERMISSION IS HEREBY GRANTED TO Parkstone Limited Partnership Parkstone at Landfall New Hanover County FOR THE construction, operation and maintenance of 2 detention ponds in compliance with the provisions of 15A NCAC 2H .1000 (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 Water Quality and considered a part of this permit. This permit shall be effective from the date of issuance until September 22, 2008 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 on page 3 of this permit, the Project Data Sheet. The subdivision is permitted for 40 lots, each limited to a maximum built -upon area as follows: the 13 existing Woodbridge Lots: Lots 4,36,38, & 39 @3,200 ft2; Lot 1 @3,400 ftz; Lots 5,7,35,37 & 40 @3,600 ft2; Lot 6 @3,900 ft2; Lots 2 & 3@4,180; the 27 Parkstone Lots: Lot 21 @3,600 ft2; Lot 24 @3,700 ftz; Lots 1-4,6,7,18,19 23, & 26 @3,800 ftz; Lots 8,17,20 & 22 @3,900 ft2; Lots 5,10,11,12,15,16,25, &27 @4,000 ftz; Lot 13 @4,100 ftz; Lot 9 @4,200 ftz; and Lot 14 @4,300 ftz. 3. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 2 State Stormwater Management Systems Permit No. SW8 950701 Modification DIVISION OF WATER QUALITY PROJECT DATA SHEET Project Name: Parkstone at Landfall Permit Number: 950701 Modification Location: New Hanover County Applicant: Mr. Ken Gebert, President Colony Coast Contractors, Inc., General Partner Mailing Address: Parkstone Limited Partnership 610 Gunston Lane Wilmington, NC 28405 Application Date: April 29, 1998 Water Body Receiving Stormwater Runoff: Molts Channel Classification of Water Body: "SB 4" POND1 POND2 Pond Depth, feet: 5.5 7.5 Permanent Pool Elevation, FMSL: 9 8.9 Total Impervious Surfaces, ftz: 104,282 134,122 Lots *69,000 **82,960 Roads/Parking, ftz 32,690 40,396 Other, ftz Parking, 2,592 Sidewalks & Parking, 10,766 Offsite Area entering Pond, ftz: none, per Engineer Required Surface Area, fie: 6,483 3,945 Provided Surface Area, fie: 8,413 4,490 Required Storage Volume, ft': 8,761 11,243 Provided Storage Volume, ft3: 9,337 14,940 Temporary Storage Elevation, FMSL: 10 11.3 Controlling Orifice: 1.5"$ pipe 1.5"$ pipe *Parkstone Lots 1-7, 17-27 **Woodbridge Lots 1-7, 35-40 and Parkstone Lots 8-16. I State Stormwater Mana.-ement Systems Permit No. SW8950701 Modigutim 4. No homeowner/lot owner/developer shall fill in, alter, or pipe any drainage feature (such as swales) shown on the approved plans as part of the stormwater management system without submitting a revision to the permit and receiving approval from the Division. 5. The permittee is responsible for verifying that the proposed built -upon area does not exceed the allowable built -upon area. Once the lot transfer is complete, the built -upon area may not be revised without approval from the Division of Water Quality, and responsibility for meeting the built -upon area limit is transferred to the individual property owner. The following items will require a modification to the permit: a. Any revision to the approved plans, regardless of size. b. Project name change. C. Transfer of ownership. d. Redesign or addition to the approved amount of built -upon area. e. Further subdivision of the project area. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan In addition, the Director may determine that other revisions to the project should require a modification to the permit. 7. 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. 8. Sheet C-4 received November 9, 1995 will continue to be the approved detail detail sheet for Pond 2. II. SCHEDULE OF COMPLIANCE 1. The stormwater management system shall be constructed in it's entirety, vegetated and operational for its intended use prior to the construction of any built -upon surface except roads. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. The permittee grants permission to DENR Staff to enter the property for the purposes of inspecting the project for compliance with the conditions of this permit. 4. 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. 5. Decorative spray fountains will not be allowed in the pond. State Stormwater Management Systems Permit No. SW8 950701 Modification The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stonmwater 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 side slopes. d. Immediate repair of eroded areas. e. Maintenance of side slopes in accordance with approved plans and specifications. f. Debris removal and unclogging of outlet structure, orifice device and catch basins and piping. g. Access to the outlet structure must be available at all times. 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. Prior to the sale of any lot, deed restrictions must be recorded which limit the built -upon area per lot to the amount as shown on the Project Data Sheet, per Section 1, Part 2. The recorded statements must follow the form: a. "The maximum built -upon area per lot is limited as follows: the existing Woodbridge Lots: Lots 4,36,38, & 39 @3,200 ft; Lot 1 @3,400 ft'; Lots 5,7,35,37 & 40 @3,600 ftZ; Lot 6 @3,900 ft'; Lots 2 & 3@4,180; 27 Parkstone Lots: Lot 21 @3,600 ftZ; Lot 24 @3,700 ft'; Lots 1-4,6,7,18,19,23, & 26 @3,800 ft'; Lots 8,17,20 & 22 @3,900 ft'; Lots 5,10,11,12,15,16,25, &27 @4,000 ft'; Lot 13 @4,100 ft'; Lot 9 @4,200 ft'; Lot 14 @4,300 ft', inclusive of that portion of the right-of-way between the lot line and the edge of pavement, structures, pavement, walkways of brick, stone, or slate, but not including open wood decking or the water surface of swimming pools." b. "The covenants pertaining to stormwater regulations may not be changed or deleted without concurrence of the State." C. "Alteration of the drainage as shown on the approved plan may not take place without the concurrence of the State." d. "All runoff from each lot must drain into the permitted system. This may be accomplished through providing roof drain gutters which drain to the street, grading the lot to drain toward the street, or grading perimeter swales and directing them into the pond or street. Lots that naturally drain into the system are not required to provide these measures." 9. This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. 10. A copy of the recorded deed restrictions must be submitted to the Division within 30 days of the date of recording the plat. The recorded copy must be signed by the Permittee, dated, stamped with the deed book number and page, and bear the stamp/signature of the Register of Deeds. .. State Stormwater Management Systems Permit No 5W8 950701 Modification 11. Prior to transfer of ownership, the pond must be inspected by DWQ personnel, and determined to be in compliance with all permit conditions. Records of maintenance activities will be required. 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. III. GENERAL CONDITIONS This permit is not transferable. In the event there is a desire for the facilities to change ownership, or there is a name change of the Permittee, a "Name/Ownership Change Form" must be submitted to the Division of Water Quality accompanied by appropriate documentation from the parties involved, such as a copy of the deed of trust. Other supporting materials, such as a signed Operation and Maintenance plan in the case of engineered systems, will also be required. The project must be in good standing with DWQ. The approval of this request will be considered on its merits and may or may not be approved. 2. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to enforcement action by the Division of Water Quality, in accordance with North Carolina General Statute 143-215.6A to 143-215.6C. 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) which have 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. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit modification, revocation and reissuance or termination does not stay any permit condition. Permittee grants permission to staff of the DWQ to access the property for the purposes of inspecting the stormwater facilities during normal business hours. Permit issued this the 22nd day of September, 1998. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION DIti i n /. � A. Preston Howard, Jr., P.E., Director Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW8 950701 Modification G7 State Stormwater Management Systems Permit No SW8950701 Modification Parkstone at Landfall Stormwater Permit No. SW8 950701 Modification New Hanover County Engineer's Certification 1, , as a duly registered Professional Engineer in the State of North Carolina, having been authorized to observe (periodically/weekly/full time) the construction of the project, ect) for (Project Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the project construction such that the construction was observed to be built within substantial compliance and intent of the approved plans and specifications. Noted deviations from approved plans and specifications: Signature Registration Number Date SEAL 7 STORU AI � D E C E I V E POND MAINTENANCE RE UIItEA�* JUL 16 1998 D Project Namffa 6e: 4eai I,.J, Q Ts Q a+ I I PAoj n� DlD� Permittee: Qh I J i n-) i� Q=64 rikl p Address:_ 2zo � n� I �ahPi PhoneNo._ I. Monthly, or after every runoff producing rainfall event, whichever comes fast: A. Inspect the trash rack; remove accumulated debris, repair/replace if it is not functioning. B. Inspect and clear the orifice of any obstructions. If a pump is used as the drawdown mechanism, pump operation will be checked. A log of test runs of the pump will be kept on site and made available to DWQ personnel upon request. C. Inspect the pond side slopes and grassed inlet swales; remove trash, and repair eroded areas before the next rainfall event. D. If the pond is operated with a vegetated filter, the filter will be checked for sediment accumulation, trash accumulation, erosion and proper operation of the flow spreader mechanism. Repairs/cleaning will be done as necessary. H. Quartetly (Four times a year): A. Inspect the collection system (ie. catch basins, piping, grassed swales) for proper functioning. Accumulated trash will be cleared from basin grates, basin bottoms, and piping will be checked for obstructions and cleared as required. B. Pond inlet pipes will be checked for undercutting. Riprap or other energy dissipation structures will be replaced, and broken pipes will be repaired. III. Semi-annually (twice a year): r:, 1. A. Accumulated sediment from the bottom of the outlet structure will be removed. B. The forebay depth will be checked at various points. Sediment removal is required when the depth is reduced to 75 % of the original forebay design depth of K C. Grassed swales, including the vegetated filter if applicable, will be reseeded twice a year as necessary. nnPori = , � A POND MAINTENANCE REQUIREMENTS PAGE 2 IV. Annually (Once a year): A. The pond depth will be checked at various points. Sediment removal is required when the depth is reduced to 75 % of the original design depth or 3', whichever is greater. Design depth is ', measured vertically from the orifice down to the pond's bottom. Sediment must be removed to at least the original design depth. V. General: A. Mowing of the side slopes will be accomplished according to the season. Maximum grass height will be 6". B. Cattails are encouraged along the pond perimeter, however they will be removed when they cover more than 1/2 the surface area of the pond. The best time to cut them is at the end of the growing season, in November. Environmentally sensitive chemicals for use in killing cattails can also be used. Contact your nearest Agricultural Extension Agent. C. The orifice/pump is designed to draw down the pond in 2-5 days. If drawdown is not accomplished in that time, the orifice will be replaced with a larger or smaller orifice. Slow drawdown may be attributed to a clogged system. The source of the clogging will be found and eliminated. D. All components of the detention pond system will be kept in good working order. Repair or replacement components will meet the original design specifications as per the approved stormwater plan. If previously approved components are determined to be ineffective, the component must be redesigned and/or replaced. VI. Special Requirements: I, — �g*)fon 9• &40121e� rt , hereby ack-nowledge that I am the financially (please print or type natne clearly) responsible party for maintenance of this detention pond. I will be responsible for the performance of the maintenance -as outlined above,/as part of the Stormwater Management Permit received for this project. Signature: Datei Revised 2125/97 . Lf�t� ,.. C. Y ' ale eceiveFee Paid,ennit Number State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form may be photocopied for use as an original I. GENERAL INFORMATION 1. Applicants name (spgcify the name of tjre -env 2. Print Owner/Signing Official's name and title (the person its compliance):, I t 3. Mailing Address for person listed in item 2 above: CityI �I I I m 1 nq 1Z�) n Telephone Number. ( I IQ j 12—E&_ who ownstthe project): is legally retsponsible for the facility and r�I 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, pperation and maintenance agreements, etch: , i 5. Location of Facility (street address) Ov. r, County 6. Directions to facility (fro nearest m�jpr intersection : I U��" I c7 �Jol 1�S b r. of l V r o e►" n� 1 G� 7. Latitude: Longitude of facility B. Contact Ferrson who can answer questions about the facility: Nano LZOn < Telephone Number: ( I I D ) 'L ✓Cl/— II. PERMIT INFORMATION: 1. Specify whether project is (check one): New Renewal Modification 2. If this application is being suamitted as the re ult of a renewal or modification to an exist' g�err 't list the existing pennitnumber_5 W �7 qr2 O10 1 and its issue date (if known) Form SWU-101 January 1998 Page 1 of 4 i4 3. Specify the type of project (check one): _Low Density ,High Density _Redevelop _General Permit _Other 4. Additional Project Requir�etr/tents (check applicable blanks): _CAMA Major / 1 Sedimentation/Erosion Control III. PROJECT INFORMATION _404 Permit 1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (ong to two pages) describipg stormwater management for the project. e sL1�Ies 2. Stormwater runoff from this project drains to the �., hee River basin. �/^ 3. Total Project Area: acres 4. Project Built Upon Area: `4o. 5. How many drainage basins does the project have? 2 6P4&ffW- i�MiT 41-r, 6. Complete the following information for each drainage basin. If there are more than two drainage basins in the project, attach an additional sheet with the information for each basin rovided in the same format as below. f jai' I� e • � 'Basin 'Informatlon%3 ``, r Receivin Stream Name Receiving Stream Class Drainage Basin Area h,116 Existing Impervious* Area Proposed Im ervious"Area Q p % Impervious Area (total) O o Im ervlous:Sucfa`ceArea". "'' , ,:- Drama' . ,Brim l re ,',,r ea �s sprains eiBastnF2 ,1 ��„x' On -site Build ins C7 On -site Streets On -site Parkin p On -site Sidewalks Other on -site Off -site Totald k E_ iwu5 area is defined ed areas, etc.tt upon area including, but not limited too,,, buildings, roads, parking areas, 7. How was the off -site impervious area listed above derived? k 65E IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS Deed restrictions and protective covenants are required to be recorded for all low density projects and all subdivisions prior to the sale of any lot. Please see Attachment A for the specific items that must be recorded. Form SWU-101 January 1998 Page 2 of 4 By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the items required by the permit, 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. If you wish to designate submittal authority to another individual or firm so that they may provide information on your behalf, please complete this section: Designated agent (individual or fum): GCS F—,e h %f n nc VII. SUBMITTAL REQUIREMENTS This application package will not be accepted by the Division of Water Quality unless all of the applicable items are included with the submittal. 1. Please indicate that you have provided the following required information by signing your initials in the space provided next to each item. • Original and one copy of the Stormwater Management Permit Application Form • One copy of the applicable Supplement Form(s) for each BMP (see Attachment A) • Permit application processing fee (see Attachment A) • Two copies of plans and specifications including: • Detailed narrative description of stormwater treatment/management • Two copies of plans and specifications, including: - Development/Project name - Engineer and firm - Legend - North arrow - Scale - Revision number & date - Mean high water line - Dimensioned property/project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Details of roads, parking, cul-de-sacs, sidewalks, and curb and gutter - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage basins delineated - Vegetated buffers (where required) V. APPLICANT'S CERTIFICATION 1; (print or type name of person listed in General Information, itent 2) Von V e k r4 certify that the information, included on this permit application form is correct, that the project will be constructed in conformance with the approved plans, that the deed restrictions in accordance with Attachment A of this form will be recorded with all required permit conditions, and that to the best of my knowledge the proposed project co lies with the requirements of 15A NCAC 21-1.1000. Signature /J/` � 9�,ZioGt� . Date -.— Form SWU-101 January 1998 Page 3 of 4 ATTACHMENT A 1. Deed Restriction Language The following statements must be recorded for all low density projects and for all projects that involve the subdivision and selling of lots or outparcels: I. No more than _ square feet of any lot, including that portion of the right-of-way between the edge of pavement and the front lot line, shall be covered by impervious structures including asphalt, gravel, concrete, brick, stone, slate or similar material but not including wood decking or the surface of swimming pools. This covenant is intended to insure continued compliance with the stormwater permit issued by the State of North Carolina. The covenant may not be changed or deleted without the consent of the State. No one may fill in, pipe, or alter any roadside Swale except as necessary to provide a minimum driveway crossing. NOTE: If lot sizes vary significantly, the owner/developer must provide an attachment listing each lot number, size and the allowable built -upon area for each lot. For commercial projects that have outparcels or future development the following statements must also be recorded: 3. The connection from file outparcel or future area into the stormwater system must be made into the forebay such that short-circuiting of tine system does not occur. 4. All built -upon area from the outparcel or future development must be directed into the permitted stormwater control system. 5. Built -upon area in excess of the permitted amount will require a permit modification prior to construction. For curb outlet systems, the following statement in addition to items 1 and 2 above must be recorded: 6. No one may pipe, fill in or alter any designated 100 foot long grassed swale used to meet the requirements of NCAC 2H .1008(g). 2. Supplement Forms The applicable supplement form(s) listed below must be submitted for each BMP specified for this project: Form SWU-102 Wet Detention Basin Supplement Form SWU-103 Infiltration Basin Supplement Form SWU-104 Low Density Supplement Form SWU-105 Curb Outlet System Supplement Form SWU-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Nutrient Management Strategy Supplement 3. Permit Application Fees (check made payable to NCDENR and submitted to the appropriate Regional Office) Type of Permit Low Density High Density Other Director's Certification General Permit New, Modification, or Late Renewal $225 $385 $225 $350 $50 Timely Renewal Without Modification n/a $225 n/a n/a n/a Form SWU-101 January 1998 Page 4 of 4 CAPE FEAR Engineering, Inc. 3963 Market Street Wilmington, N.C. 2a403 voice (910) 772-9600 Fax (910) 772-9679 E-mail capfeng@bellsouth.net To: N.C.D.E.N.R. Division of Water Quality 127 Cardinal Drive Ext. Wilmington, N.C. 28405-3845 ATTENTION. Linda Lewis RECEIVED JUL 161998 BY: Transmittal DATE: 7/13/98 PROJECT No 208-01 _98 RE: Parkstone Subdivision @ Landfall Modification of Permit # SW8 950701 Quantity Drawing No. Description t Maintenance Agreement for both ponds 2 Sets Revised Stormwater Master Plan REMARKS Resubmittal addressing your comments. If you have any questions or require additional information please contact our office. CC: Ken Gebert, Owner CAPE F -n ineering, Inc. File Signed State of North Carolina Department of Environment and Natural Resources Wilmington Regional Office James B. Hunt, Jr., Governor Wayne McDevitt, Secretary Division of Water Quality June 23, 1998 Mr. Mark Ashness, P.E. Cape Fear Engineering 3963 Market Street Wilmington, NC 28403 INCDENR NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES Subject: ACKNOWLEDGEMENT OF RECEIPT AND REQUEST FOR ADDITIONAL INFORMATION Stormwater Project No. SW8 950701 Parkstone @Landfall New Hanover County Dear Mr. Ashness: The Wilmington Regional Office received a Stormwater Management Permit Application for Parkstone @Landfall on April 29, 1998. A preliminary review of that information has determined that the application is not complete. The following information is needed to continue the stormwater review: 1. Please provide existing and proposed contours, spot elevations, finished floor elevations, inverts and top elevations for the homes, roads, drives, piping, and catch basins. The previously approved plans under Woodbridge will be superceeded by this permit modification, so the approved plans must be complete in all items. 2. Please provide dimensions for the roads, property lines, and permanent pool of both ponds. 3. Since this is a modification and both ponds are included in the application, please provide the pond section and outlet details for Pond 2. 4. Delineate all wetlands on site, or note on the plans that none exist. 5. Locate the pond in a recorded access/drainage easement. 6. Please refer to the enclosed Operation and Maintenance plan. Several of the items are missing from the one submitted, including the monthly inspection requirement, forebay sediment removal, reseeding, cattail removal, accomplishment of drawdown within 2-5 days, and the repair/replacement of all components of the detention pond and collection system to the permitted design condition. Please either add these requirements to the submitted document, or have the enclosed document signed by the owner. It is not necessary to sign separate documents for each pond. One O & M with both ponds' depths listed will suffice. Additionally, a notary signature is no longer required. 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone 910-395-3900 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post -consumer paper Mr. Ashness June 23, 1998 Stormwater Project No. SW8 950701 7. Please add the direction and distance to at least one more named road, such as Military Cutoff on the location map. Please note that this request for additional information is in response to a preliminary review. The requested information should be received by this Office prior to July 18, 1998, or the application will be returned as incomplete. The return of a project will necessitate resubmittal of all required items, including the application fee. If you have any questions concerning this matter please feel free to call me at (910) 395-3900. RSS/arl: cc: Sincerely, /'4� � 4.� Ms. Linda Lewis Environmental Engineer S:\WQS\STORMWAT\ADDINFO\950701.JUN Linda Lewis Central Files 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone 910-395-3900 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer - 50% recycled/10 % post -consumer paper CAPE FEAR 4 Engineering, 1 3963 Market Street Wilmington, N.C. 28403 Votes (910) 772-9600 Fox (910)772-9979 E-mil capfeng@bellsouth.net TO: N.C.D.E.N.R. Division of Water Quality 127 Cardinal Drive Ext. Wilmington, N.C. 28405-3845 ATTENTION: Linda Lewis Transmittal DATE: 4/28/98 PROJECT NO: 208-01 _98 RE: Parkstone Subdivision @ Landfall Modification of Permit # SW8 950701 Quantity Drawing No. Description 1 Set Original Approved Plan with Approval Letter 2 Sets Revised Stormwater Master Plan 2 Sets Detailed Stormwater Plan noting modifications 2 Sets Stormwater Permit Application with Wet Detention Basin Supplement 1 Check Plan Review Fee — Check for $385.00 2 Sets Stormwater Narrative with Calculations 1 Set House Plan Footprint 1 Set Maintenance Agreement for each Pond REMARKS Attached is information for stormwater permit approval. If you have any questions or require additional information please contact our office. CC: Ken Gebert, Owner rAPE F, g' ring, Inc. File fTJ Signed Mark P. Ashness, PE Impervious Area Comparision Parkstone @ Landfall 4/28/98 Detention Pond #1 - Impervious Surface Breakdown Pond Revised from prior Permit New New New Home New Lot New Lot # Old Lot # Home Driveway Sidewalk Total 1 26 3,052 sf 510 sf 200 sf 3,800 sf 2 27 3,052 sf 510 sf 200 sf 3,800 sf 3 28 3,052 sf 510 sf 200 sf 3,800 sf 4 29 3,052 sf 510 sf 200 sf 3,800 sf 5 30 3,052 sf 653 sf 200 sf 4,000 sf 6 31 3,052 sf 531 sf 200 sf 3,800 sf 7 32 3,052 sf 451 sf 200 sf 3,800 sf 17 15 3,052 sf 553 sf 200 sf 3,900 sf 18 16 3,052 sf 476 sf 200 sf 3,800 sf 19 17 3,052 sf 476 sf 200 sf 3,800 sf 20 18 3,052 sf 579 sf 200 sf 3,900 sf 21 19 3,052 sf 259 sf 200 sf 3,600 sf 22 20 3,052 sf 560 sf 200 sf 3,900 sf 23 21 3,052 sf 518 sf 200 sf 3,800 sf 24 22 3,052 sf 388 sf 200 sf 3,700 sf 25 23 3,052 sf 685 sf 200 sf 4,000 sf 26 24 3,052 sf 484 sf 200 sf 3,800 sf 27 25 3,052 sf 691 sf 200 sf 4,000 sf Revised Plan Impervious Breakdown Lots 69,000 sf 4,059 avg. per lot Roadways 25,207 sf Sidewalks 7,483 sf Pond has been revised to accommodate Parking Areas 2,592 sf the increase in impervious area 104,282 sf 103,050 sf Previously Permitted 4 Detention Pond #2 - Impervious Surface Breakdown No physical change to Pond #2 New New New Home New Lot New Lot # Old Lot # Home Driveway Sidewalk Total (Parkstone) (Woodbridge) Impervious Impervious Impervious Impervious 1 - sf 0 sf 0 sf - sf 2 - sf 0 sf 0 sf - sf 3 - sf 0 sf 0 sf - sf 4 - sf 0 sf 0 sf - sf 5 - sf 0 sf 0 sf - sf 6 - sf 0 sf 0 sf - sf 7 - sf 0 sf 0 sf - sf 10 8 3,052 sf 535 sf 400 sf 4,000 sf 11 9 3,052 sf 488 sf 400 sf 4,000 sf 12 10 3,052 sf 505 sf 400 sf 4,000 sf 13 11 3,052 sf 608 sf 400 sf 4,100 sf 14 12 3,052 sf 751 sf 400 sf 4,300 sf 15 13 3,052 sf 519 sf 400 sf 4,000 sf 16 14 3,052 sf 472 sf 400 sf 4,000 sf 8 33 3,052 sf 371 sf 400 sf 3,900 sf 9 34 3,052 sf 662 sf 400 sf 4,200 sf 35 - sf - sf - sf - sf 36 - sf - sf - sf - sf 37 - sf - sf - sf - sf 38 - sf - sf - sf - sf 39 - sf - sf - sf - sf 40 - sf - sf - sf - sf Totals 27,468 sf 4,911 sf 3600 sf 36,500 sf Revised Plan Impervious Breakdown Lots 36,500 sf 1,587 avg.perlot Roadways 40,396 sf Sidewalks 7,334 sf Parking Areas 3,432 sf 87,662 sf 137,930 sf Permitted Previously N —ts� t -F No.5505 Engineers Computation Pad �� 6 124> Engine 5 Engineers Computation Pad STORMWATER CALCULATIONS - Parkstone Pond #1 Stage - Storage Entire Pond Contour Contour Incr. Accum. Elev. Area Storage Storage (S) (11) (so (co (cf) 3.5 325 0 211 4.0 519 211 772 5.0 1,025 983 1,417 6.0 1,808 2,400 2,457 7.0 3,105 4,856 3,922 8.0 4,739 8,778 9.0 8,413 6,576 = l� 15,354 �I �� 10.0 10,260 9,337 C, 24,691 - -(Or ar- 5,994 10.5 13,717 30,685 Stage - Storage Foreba Contour Contour Incr. Accmn. Elev. Area Storage Storage (S) (n) (sfl (c9 (c>) 6.0 133 0 374 7.0 615 374 983 8.0 1,350 1,357 9.0 2,148 1,749 r 3,106 CM v! 1 - Manual - 10 Yr - Qp = 18.62 cfs 20 15 Q cfs 10 Out 5 0.0 0.5 1.0 1.5 2.0 2.5 Time (hrs) Inflow Hvdrograph - Q10 Peak Inflow, (Qp) => Tunc to Peak Calculation: CN= Q"= Time to Peak, (Tp) => (SCS TR-55) 18.6 cfs 80 P= 4.8 2.72 (inches of nmofi) 32.88 minutes 1/tp QDR t Q 0.00 0.000 0 0.00 0.06 0.009 2 0.17 0.12 0.036 4 0.67 0.18 0.080 6 1.49 0.24 0.139 8 2.59 0.30 0.211 10 3.94 0.37 0.294 12 5.49 0.43 0.385 14 7.17 0.49 0.479 16 8.93 0.55 0.574 18 10.71 0.61 0.667 20 12.44 0.67 0.753 22 14.05 0.73 0.831 24 15.49 0.79 0.896 26 16.71 0.85 0.947 28 17.65 0.91 0.981 30 18.30 0.97 0.998 32 18.62 1.03 0.997 34 18.59 1.10 0.978 36 18.24 1.16 0.941 38 17.55 1.22 0.889 40 16.57 1.28 0.825 42 15.38 1.34 0.762 44 14.21 1.40 0.704 46 13.13 1.46 0.650 48 12.13 1.52 0.601 50 11.21 1.58 0.555 52 10.35 1.64 0.513 54 9.57 1.70 0.474 56 8.84 1.76 0.438 58 8.17 1.83 0.405 60 7.55 1.89 0.374 62 6.97 1.95 0.345 64 6.44 2.01 0.319 66 5.95 2.07 0.295 68 5.50 2.13 0.272 70 5.08 2.19 0.252 72 4.69 2.25 0.233 74 4.34 2.31 0.215 76 4.01 2.37 0.199 78 3.70 2.43 0.183 80 3.42 2.49 0.170 82 3.16 S= 2.50 MA 2.56 0.157 84 2.92 2.62 0.145 86 2.70 2.68 0.134 88 2.49 2.74 0.124 90 2.30 2.80 0.114 92 2.13 2.86 0.105 94 1.97 2.92 0.097 96 1.82 2.98 0.090 98 1.68 3.04 0.083 100 1_55 3.10 0.077 102 1.43 3.16 0.071 104 1.32 3.22 0.066 106 1.22 3.29 0.061 108 1.13 3.35 0.056 110 1.04 3.41 0.052 112 0.97 3.47 0.048 114 0.89 3.53 0.044 116 0.82 3.59 0.041 118 0.76 3.65 0.038 120 0.70 3.71 0.035 122 0.65 3.77 0.032 124 0.60 3.83 0.030 126 0.55 3.89 0.027 128 0.51 3.95 0.025 130 0.47 4.02 0.023 132 0.44 4.08 0.022 134 0.40 4.14 0.020 136 0.37 4.20 0.019 138 0.35 4.26 0.017 140 0.32 4.32 0.016 142 0.29 4.38 0.015 144 0.27 4.44 0.013 146 0.25 4.50 0.012 148 0.23 4.56 0.012 150 0.21 4.62 0.011 152 0.20 4.68 0.010 154 0.18 4.75 0.009 156 0.17 4.81 0.008 158 0.16 4.87 0.008 160 0.14 4.93 0.007 162 0.13 4.99 0.007 164 0.12 5.05 0.006 166 0.11 Stage / Discharge 3.0 2.5 2.0 tage (ftf 5 1.0 0.5 0.00 20 40 60 80 100 Discharge (cfs) a Stage / Storage 3.0 2.5 2.0 tage (ftf 5 1.0 0.5 0-8.0 0.2 0.4 0.6 0.8 1.0 Storage (acft) 2 - Reservoir - 10 Yr - Max. E1. = 10.5 f 11.0 10.6 10.2 lev (ft) 9.8 9.4 9.01 .0 0.5 1.0 1.5 2.0 2.5 Time (hrs) In 2 - Reservoir - 10 Yr - Qp = 18.12 cfs 20 15 / 4 cfs 10 In 5 / Out 0.0 0.5 1.0 1.5 2.0 2.5 Time (hrs) Page 1 Hydrograph Summary Report Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time Interval (min) Time to peak (min) volume (acft) Return period (yrs) Inflow hyd(s) Maximum elevation (ft) Maximum storage (acft) Hydrograph description 1 Manual 18.6 2 32 1.17 10 — 10 YR Hydo 2 Reservoir 18.1 2 36 1.14 10 1 10.50 0.35 tOYR Proj. file: 0428.GPW IDF file: WILKIDF Run date: 04-28-1998 Hydrograph Report Page Hyd. No. 2 10 YR Hydrograph type = Reservoir Storm frequency = 10 yrs Inflow hyd. No. = 1 Max. Elevation = 10.50 ft Peak discharge = 18.12 cfs Time interval = 2 min Reservoir name = Pond #1 Max. Storage = 0.35 acft Storage indication method used. Total Volume = 49,667 ouft, 1.14 aoft Hydrograph Discharge Table Time Inflow Elevation Culy. A Culy. B Culy. C Weir A Weir B Weir C Outflow (hrs) (cfs) (ft) (cfs) (cfs) (Cfs) (cfs) (cfs) (cfs) (cfs) 0.23 7.07 9.23 0.02 ----- ----- ----- ----- ----- 0.02 0.27 8.93 9.34 0.03 ----- ----- ----- ----- - 0.03 0.30 10.71 9.47 0.06 ----- ----- ----- ----- - 0.06 0.33 12.44 9.62 0.09 ----- - -- - 0.09 0.37 14.05 9.79 0.13 ----- ----- ----- ----- ----- 0.13 0.40 15.49 9.98 0.17 ----- ----- ---- ----- ----- 0.17 0.43 16.71 10.14 0.20 -- 1.52 ----- ----- 1.72 0.47 17.65 10.27 0.22 ----- ----- 4.32 ----- ----- 4.54 0.50 18.30 10.39 0.23 ----- ----- 7.35 ----- ----- 7.58 0.53 18.62 << 10.47 3.30 ----- ----- 9.72 ----- - - 13.02 0.57 18.59 10.50 7.37 ----- --- 10.65 ----- - 18.03 0.60 18.24 10.50 << 7.39 ----- ----- 10.74 ----- ----- 18.12 << 0.63 17.55 10.50 7.38 ----- ----- 10.69 ----- ----- 18.07 0.67 16.57 10.50 6.88 ----- ----- 10.50 ----- ----- 17.39 0.70 15.38 10.49 5.82 ----- 10.27 ----- ----- 16.09 0.73 14.21 10.48 4.84 ----- ---- 10.06 ----- ----- 14.90 0.77 13.13 10.48 3.91 ----- -- 9.86 ----- --- 13.77 0.80 12.13 10.47 3.05 ----- - 9.67 ----- - 12.72 0.83 11.21 10.46 2.26 - -- 9.50 - - 11.75 0.87 10.35 10.46 1.52 ----- -- 9.34 --- -- 10.86 0.90 9.57 10.45 0.84 ---- -- 9.19 ----- - 10.03 0.93 8.84 10.45 0.24 ----- - 9.05 -- - 9.29 0.97 8.17 10.44 0.24 ---- - 8.85 ----- ----- 9.09 1.00 7.55 10.43 0.24 - - 8.54 -- - 8.78 1.03 6.97 10.42 0.24 -- - 8.16 -- - 8.40 1.07 6.44 10.40 0.23 ----- - - 7.73 ----- - 7.97 1.10 5.95 10.39 0.23 ----- ---- 7.30 ----- ----- 7.54 1.13 5.50 10.37 0.23 ----- - 6.87 ----- - 7.10 1.17 5.08 10.36 0.23 ----- -- 6.44 ----- ----- 6.67 85% TSS REMOVAL 30 TOOT VEGETATED FILTER RE, QUntED DEPTH 3' 3.5' 4.0' 4.5' 5.0' 5.5' 6.0' 6.5' 7.0' 7.5' IMP % 10 % .9 .8 .7 .6 .5 0 0 0 0 0 20 % 1.7 1.3 1.2 1.1 1.0 .9 .8 .7 .6 .5 30 % 2.5 2.2 1.9 1.8 1.6 1.5 1.3 1.2 1.0 .9 40 % 3.4 3.0 2.6 2.4 2.1 1.9 1.6 1.4 1.1 1.0 50 % 4.2 3.7 3.3 3.0 2.7 2.4 2.1 1.8 1.5 1.3 60 % 5.0 .4.5 3.8 3.5 3.2 2.9 2.6 2.3 2.0 1.6 70 % 6.0 5.2 4.5 4.1 3.7 3.1 2.9 2.5 2.1 1.8 80 % 6.8 ;i 6.0 5.2 4.7 4.2 3.7 3.2 2.7 2.2 2.0 90 % 7.5 6.5 5.8 5.3 4.8 4.3 3.8 3.3 2.8 1.3 100 % 8.2 7.4 6.8 6.2 5.6 5.0 4.4 3.8 3.2 2.6 90% TSS REMOVAL NO VEGETATED FILTER RE,QUIIMED 3.5' 4.0' 4.5' 5.0' 5.5' 6.0' 6.5' 7.0' 7.5' I3' 1.3 1.0 .8 .7 .6 .53 22.4 2.0 1.8 1.7 1.5 1.4 1.2 1.0 .9 .6 30 % 3.5 3.0 2.7 2.5 2.2 1.9 1.6 1.3 1.1 .8 40 % 4.5 4.0 3.5 3.1 2.8 2.5 2.1 1.8 1.4 1.1 50 % 5.6 5.0 4.3 3.9 3.5 .1 2.7 2.3 1.9 1.5 60 % 7.0 6.0 5.3 4.8 4.3 3.9 3.4 2.9 2.4 1.9 70 % 8.1 7.0 6.0 5.5 5.0 4.5 3.9 3.4 2.9 2.3 80 % 9.4 8.0 7.0 6.4 5.7 5.2 4.6 4.0 3.4 2.8 90 % (10.7) 9.0 7.9 7.2 6.5 5.9 5.2 4.6 3.9 3.3 LIM8100 % 12.0 10.0 8.8 .1 7.3 6.6 5.8 5.1 4.3 3.6 Note: The required surface area calculated from the tables is to be provided at the permanent pool elevation. x n Military u -o / Imo) Arboretum Gate ❑ -�-r ?�'�" DR��t� nL�n2�-(UYv� - - .� 2r 1'\ ` w� Summe ands -]-TJ N, 4<2,,k c1 4b `o School Bus Stop ❑ as F6ay ❑ Dsdale Postal Center ❑ CV a E ip Gate - 3 GHAPEL� c a ° Sorts ~ Center® Recreation Q� C `'Srn4r �a� Postal Ctr. ❑ Field Information Cente 256-6111 `Jee�\e a2/L a School , ^ ARB / PDA �? 256-7651 a�qs y i da =3 Bus Stop/¢�� r Administration t, 256-7646 e$P 6oP MontroseLn. o a ❑ Qe F Landfall Club to 256-8411 m f6 o m °' Nicklaus Golf 256-7635 m roc ' T ; 0 Kenilworth L� L oc o f Dye Golf l's 256-9050d o'p`oO ��' Ma��� Sports Center nl 256-7625 a�ca dge aC� m o to Ainsdalo Gl. N A r / w c Pub �'� t ` Landfall 5 m a3i T'$�.'� Club ® C gg s eJ r\¢Js'na /p 1c gets e�eQ a `C y 3 U S9 O�QS Ver w❑ S a r,c Ter. iOia�O�e �i; ra�ano Or 6� s a N ScCrrtshaw p4� _ ao\�. N Orion PI. z I a Y 6I C a wiitzzano Pl. f.0 ` o+ ° C • Verra_ vu I iV s- Fox Ridge PI. oa�C�ae� o y i Um ro Verr T^ 0 3 `o w `Ph a22ano pr U piano CT o a x e Oe \c14et c, \ Golf MainL❑Ctr. Fox Ridge Ln. .o U` d sse S m m h = sryy P Landalee Ln. o` ao` a Wild Turkey 6o w U Ze Seeova Tt Vh`J� y `J S 3/ F°- mCl, L) ° P Pinehurst Pl. ri m 9 c i Belevse Cf. „ �� . seawi m < G m 0 o c Pope O. Dye Club ¢ega0aDr' J C�wlWayton Point y� o DYe P/ ® " ote" Boatswain PI. P e- eo aTemplLandfall 3riv❑eaPwoodv. aidePa I V a/yaks Pe iy Shelter Cove PI. m 4 °jrr�Or, O mbfO�e%n il'R6or`o,°'� �nbe Ocean Prd9e Qr. as f�PLwrL� Paced Intracoastal Waterway P2rks{>ie- I C 7cj ( IN FEET ) 1 inch = 10 ft