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HomeMy WebLinkAbout20061223 Ver 2_More Info Received_20061220Malpass & Associatcs Engineering & Planning 1645 E. Arlington Blvd Suite D Greenville, NC 27858 I'tx;ne~ (2.52) 756-1180 Fax:1252j 156-2098 December 19, 2006 North Carolina Department of Environment and Natural Resources Division of Water Quality 401 Division ATTN: Ms. Cyndi Karoly 2321 Crabtree Boulevard Raleigh, NC 27604 RE: BROOKSTONE SUBDIVISION DWQ Project # 06-1223 Dear Ms. Karoly: Oto- 122'a .-~, s ~ ~ ° ,,, Ott . _ , "~" __-. ~ s ~~ !~~ „~~s ~' ~. ;; ._;~ , .'~~ vti`di~Cf *f~7UW'kia'.. ~ .,.., Please find enclosed the additional information requested in your letter dated December 7, 2006 regarding the above referenced project. Items 1: Included are site plans showing the proposed wetlands. The wetlands are wholly within extended dry detention basins that are required for local storrnwater regulations. The calculations were revised in October to include extended detention wetlands and are up to date. The worksheet for wetland area 1 is correct. A corrected worksheet for wetland area 2 is submitted herein. The drainage area, impervious area, and their ratio now agree with the previously submitted calculations. Item 2: A planting plan is provided on sheet 2 of the plans along with the outlet structure details. Plant species and number are provided in the table. Installation notes are also provided to optimize survival of the plants. Item 3: The operation and maintenance agreement is provided herein. Item 4: The area previously given [PCN Application Section III (6)] of 21 acres was for phase one and wetland area 1 only. A corrected page 6 of the PCN is provided showing the entire area (~49 acres). Also, page 9 item VI (8) of the PCN refers to the creation of a pond. No permanent pool other than the wetland area is planned. Therefore, I have removed this item from the application. Item 5: The inverts can be found on the plan view for all drop inlets and on the profile sheets for catch basins. If there are any questions regarding this information please contact me at (252) 756-1780 or by e-mail at Jamie@malpassandassociates.com. Sincerely, lilG~, ~ ^ ~~ j, Jamie Midgette, Engineering Intem Malpass & Associates ~c~~ad~ D DEC 2 0 ?006 III. Project Information DENR-Wq WEIIANUSANO St~p~WATER Attach a vicinity map clearly showing the location of t e pro with respect to local landmarks such as towns, rivers, and roads. Also provide a detailed site plan showing property boundaries and development plans in relation to surrounding properties. Both the vicinity map and site plan must include a scale and north arrow. The specific footprints of all buildings, impervious surfaces, or other facilities must be included. If possible, the maps and plans should include the appropriate USGS Topographic Quad Map and NRCS Soil Survey with the property boundaries outlined. Plan drawings, or other maps may be included at the applicant's discretion, so long as the property is clearly defined. For administrative and distribution purposes, the USACE requires information to be submitted on sheets no larger than 11 by 17-inch format; however, DWQ may accept paperwork of any size. DWQ prefers full-size construction drawings rather than a sequential sheet version of the full-size plans. If full-size plans are reduced to a small scale such that the final version is illegible, the applicant will be informed that the project has been placed on hold until decipherable maps are provided. 1. Name of project: Brookstone Subdivision 2. T.I.P. Project Number or State Project Number (NCDOT Only): N/A 3. Property Identification Number (Tax PIN): 10508 4. Location County: PITT Nearest Town: Winterville Subdivision name (include phase/lot number): Brookstone Subdivision Phase One Directions to site (include road numbers/names, landmarks, etc.): TAKE NC HWY 11 SOUTH FROM GREENVILLE_TO NCSR 1131 (REEDY BRANCH ROADI HEAD EAST ON REEDY BRANCH TO NCSR 1714 (CHURCH STREET EXTENSION) THE SITE IS LOCATED APPROXIMATELY 2 000 FEET NORTH OF THIS INTERSECTION 5. Site coordinates (For linear projects, such as a road or utility line, attach a sheet that separately lists the coordinates for each crossing of a distinct waterbody.) Decimal Degrees (6 digits minimum): 35.504751 °N -77.406712 °W 6. Property size (acres): +/- 48.83 7. Name of nearest receiving body of water: Swift Creek 8. River Basin: NEUSE (Note -this must be one of North Carolina's seventeen designated major river basins. The River Basin map is available at http://h2o.eru.state.nc.us/admin/maps/.) 9. Describe the existing conditions on the site and general land use in the vicinity of the project at the time of this application: SITE IS CURRENTLY AGRICULTURAL ALL ADJACENT PROPERTIES ARE EITHER CURRENTLY WOODED OR AGRICULTURAL Page 6 of 13 5. Individually list all open water impacts (including lakes, ponds, estuaries, sounds, Atlantic Ocean and any other water of the U.S.). Open water impacts include, but are not limited to fill, excavation, dredging, flooding, drainage, bulkheads, etc. Open Water Impact Site Number (indicate on ma Name of Waterbody (if applicable) Type of Impact Type of Waterbody (lake, pond, estuary, sound, bay, ocean, etc.) Area of Impact (acres) Total Open Water Impact (acres) 0.00 6. List the cumulative im act to all Waters of the U.S. resultin from the ro'ect: Stream Impact (acres): 0.0 Wetland Impact (acres): 0.000 Open Water Impact (acres): 0.000 Total Im act to Waters of the U.S. (acres) 0.0 Total Stream Impact (linear feet): 0 7. Isolated Waters Do any isolated waters exist on the property? ^ Yes ®No Describe all impacts to isolated waters, and include the type of water (wetland or stream) and the size of the proposed impact (acres or linear feet). Please note that this section only applies to waters that have specifically been determined to be isolated by the USACE. The USACE has made no determinations on site. Pond Creation If construction of a pond is proposed, associated .wetland and stream impacts should be included above in the wetland and stream impact sections. Also, the proposed pond should be described here and illustrated on any maps included with this application. Pond to be created in (check all that apply): ^ uplands ^ stream ^ wetlands Describe the method of construction (e.g., dam/embankment, excavation, installation of draw-down valve or spillway, etc.): Proposed use or purpose of pond (e.g., livestock watering, irrigation, aesthetic, trout pond, local stormwater requirement, etc.): Current land use in the vicinity of the pond: Size of watershed draining to pond: Expected pond surface area: VII. Impact Justification (Avoidance and Minimization) Specifically describe measures taken to avoid the proposed impacts. It may be useful to provide information related to site constraints such as topography, building ordinances, accessibility, and financial viability of the project. The applicant may attach drawings of alternative, lower-impact site layouts, and explain why these design options were not feasible. Also discuss how impacts Page 9 of 13 Oc.v -223 EXTENDED DETENTION WETLAND OPERATION AND MAINTENANCE AGREEMENT The wetland detention basin system is defined as the wetland detention basin, pretreatment including forebays and the vegetated filter if one is provided. Maintenance activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wetland 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. 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 wetland detention basin system semi-annually or when depth is reduced to 75% of the original design depth. 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 [wetland] detention basin or stream, etc.). If the elevation of the marsh areas exceeds the permanent pool elevation, the sediment should be removed to design levels. This shall be performed by removing the upper 6 inches of soil and stockpiling it. Then the marsh area shall be excavated six inches below design elevations. Afterwards the stockpiled soil should be spread over the marsh surface. The soil should not be stockpiled for more than two weeks. 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. Wetland planting densities in the marsh areas should be maintained by reseeding bare areas as needed. Wetland plants should be encouraged to grow in the marsh areas. 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. 7. All components of the wetland detention basin system shall be maintained in good working order. 8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All accumulated sediment and debris shall be removed from the structure, and a level elevation shall be maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or replanted as necessary. Page 1 of 2 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: KENNETH SMITH Title: OWNER Addre Phony Signs 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, ~a(~'i~-[ J m~G~q~Tf~ , a Notary PIU/blic for the State of ~~O r-}~ ~'01(1'lGc~ , County of 1~t'4'~ , do hereby certify that K.e,nrtt~'h J~m~-{~ personally appeared before me this ~ 3~ day of (7 C~-a b.e,/~ ~oolo ,and acknowledge the due execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and official seal, F i - m. T, _ -;{ ~, .. -~ it ~~ -p} ~~ SEAL My commission expires ~~~"• .2 ~-ooq Page 2 of 2 DWQ Project No. 0 to - 1 2 2 3 DIVISION OF WATER QUALITY - 401 EXTENDED DETENTION (and POCKET*) WETLAND WORKSHEET I. PROJECT INFORMATION (please complete the following information): Project Name : BROOKSTdNE SUBDIVISION Contact Person: JAMIE MIDGETTE Phone Number: 1 252 1 756-1780 For projects with multiple basins, specify which basin this worksheet applies to: WETLAND 2 -EAST OF STREAM Permanent Pool Elevation 48.00 ft. Temporary Pool Elevation 48.81 ft. Permanent Pool Surface Area 10.345 sq. ft. Drainage Area 17.94 ac. Impervious Area 4.75 ac. Forebay Surfare Area 1.583 sq. ft. Marsh 0"-9" Surface Area 3.466 sq. ft. Marsh 9"-18" Surface Area 3,724 sq. ft. Micro Pool Surface Area 1,572 sq. ft. Temporary Pool Volume 15,250 cu. ft. (elevation of the orifice invert out) (elevation of the outlet structure invert in) (water surface area at permanent pool elevation) (on-site and off-site drainage to the basin) (on-site and off-site drainage to the basin) (at permanent pool elevation approximately 15°k)* (at permanent pool elevation approximately 35%)* (at permanent pool elevation approximately 35%)* (at permanent pool elevation approximately 15%)* (volume detained on top of the permanent pool) SA/DA used 1.3 Diameter of Orifice 1.75 in. II. REQUIRED ITEMS CHECKLIST (surface area to drainage area ratio)" (draw down orifice diameter) Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance agreement. An incomplete submittal package will result in a request for additional information and will substantially delay final review and approval of the project A licants Initials ~/~ The temporary pool controls runoff from the 1 inch rain. __ ~~ The basin side slopes are no steeper than 3:1. /~ti`l A planting plan for the marsh areas with plant species and densities is provided. /l~i~/ Vegetation above the permanent pool elevation is specified. -~a~- An emergency drain is provided to drain the basin. /lam ~`! The temporary pool draws down in 2 to 5 days. __~ Sediment storage is provided in the permanent pool. ~ A sedimentidisposal area is provided. Access is provided for maintenance. A site specific, signed and notarized operation and maintenance agreement is provided. /` ~ The drainage area (including any offsite area) is delineated on a site plan. 5 ~ Plan details' for the wetland are provided. Plan details for the inlet and outlet are provided. ntenance agreement, signed and notarized by the responsible party is provided (see http:l/h2o.ehnr.state.nc.us/ncwetlands/oandm.doc). * Pocket Wetlands have different design parameters and are only assumed to remove 35% TSS -See pp.19and 20 of the NC DENR Stormwater BMP Manual, April 1999. 10% open water, 50% high marsh, 40% low marsh. DWQ Project No. ~ b - 1 Z 23 DIVISION OF WATER QUALITY - 401 EXTENDED DETENTION (and POCKET*) WETLAND WORKSHEET I. PROJECT INFORMATION (please complete the following information): Project Name : BROOKSTONE SUBDIVISION Contact Person: JAMIE MIDGETTE Phone Number: (2521756-1780 For projects with multiple basins, specify which basin this worksheet applies to: WETLAND 2 -EAST OF STREAM Permanent Pool Elevation 48.00 ft. Temporary Pool Elevation 48.81 ft. Permanent Pool Surface Area 10,345 sq. ft. Drainage Area 17.94 ac. Impervious Area 4.75 ac. Forebay Surface Area 1,583 sq. ft. Marsh 0"-9" Surface Area 3,466 sq. ft. Marsh 9"-18" Surface Area 3,724 sq. ft. Micro Pool Surface Area 1,572 sq. ft. Temporary Pool Volume 15,250 cu. ft. (elevation of the orifice invert out) (elevation of the outlet structure invert in) (water surface area at permanent pool elevation) (on-site and off-site drainage to the basin) (on-site and off-site drainage to the basin) (at permanent pool elevation approximately 15%)* (at permanent pool elevation approximately 35%)* (at permanent pool elevation approximately 35%)* (at permanent pool elevation approximately 15%)* (volume detained on top of the permanent pool) SA/DA used 1.3 Diameter of Orifice 1.75 in. II. REQUIRED ITEMS CHECKLIST (surface area to drainage area ratio)* (draw down orifice diameter) Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance agreement. An incomplete submittal package will result in a request for additional information and will substantially delay final review and approval of the project A licants Initials The temporary pool controls runoff from the 1 inch rain. The basin side slopes are no steeper than 3:1. <i`7 A planting plan for the marsh areas with plant species and densities is provided. /l~i~/ Vegetation above the permanent pool elevation is specified. Tom- An emergency drain is provided to drain the basin. /l~ ~7 The temporary pool draws down in 2 to 5 days. ~ ~ Sediment storage is provided in the permanent pool. /~ A sediment!disposal area is provided. Access is provided for maintenance. A site specific, signed and notarized operation and maintenance agreement is provided. /` t The drainage area (including any offsite area) is delineated on a site plan. - 's ~~ Plan details' for the wetland are provided. Plan details for the inlet and outlet are provided. -- '` '` -~raQO-'~-~ artd'maintenance agreement, signed and notarized by the responsible party is provided (see http:l/h2o.ehnr.state.nc.us/ncwetlands/oandm.doc). * Pocket Wetlands have different design parameters and are only assumed to remove 35°~ TSS -See pp.19and 20 of the NC DENR stormwater BMP Manual, April 1999. 10% open water, 50% high marsh, 40% low marsh. DWQ Project No. O to - t 2 2 3 DIVISION OF WATER QUALITY - 401 EXTENDED DETENTION (and POCKET*) WETLAND WORKSHEET I. PROJECT INFORMATION (please complete the following information): Project Name : BROOKSTdNE SUBDIVISION Contact Person: JAMIE MIDGETTE Phone Number: (252) 756-1780 For projects with multiple basins, specify which basin this worksheet applies to: WETLAND 2 -EAST OF STREAM Permanent Pool Elevation 48.00 ft. Temporary Pool Elevation 48.81 ft. Permanent Pool Surface Area 10,345 sq. ft. Drainage Area 17.94 ac. Impervious Area 4.75 ac. Forebay Surface Area 1.583 sq. ft. Marsh 0"-9" Surface Area 3,466 sq. ft. Marsh 9"-18" Surface Area 3,724 sq. ft. Micro Pool Surface Area 1,572 sq. ft. Temporary Pool Volume 15,250 cu. ft. (elevation of the orifice invert out) (elevation of the outlet structure invert in) (water surface area at permanent pool elevation) (on-site and off-site drainage to the basin) (on-site and off-site drainage to the basin) (at permanent pool elevation approximately 15%)* (at permanent pool elevation approximately 35%)* (at permanent pool elevation approximately 35%)* (at permanent pool elevation approximately 15%)* (volume detained on top of the permanent pool) SA/DA used 1.3 Diameter of Orifice 1.75 in. II. REQUIRED ITEMS CHECKLIST (surface area to drainage area ratio)* (draw down orifice diameter) Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance agreement. An incomplete submittal package will result in a request for additional information and will substantially delay final review and approval of the project Ap licants Initials The temporary pool controls runoff from the 1 inch rain. -~ fib The basin side slopes are no steeper than 3:1. ~/~ri`~ A planting plan for the marsh areas with plant species and densities is provided. Vegetation above the permanent pool elevation is specified. --~~ An emergency drain is provided to drain the basin. /l~ ~`/ The temporary pool draws down in 2 to 5 days. i'~f~ Sediment storage is provided in the permanent pool. /7 A sediment!disposal area is provided. Access is provided for maintenance. f A site specific, signed and notarized operation and maintenance agreement is provided. /` r The drainage area (including any offsite area) is delineated on a site plan. 5 ~- ~ Plan details' for the wetland are provided. Plan details for the inlet and outlet are provided. ntenance agreement, signed and notarized by the responsible party is provided (see http:/lh2o.ehnr.state.nc.us/ncwetlands/oandm.doc). * Pocket Wetlands have different design parameters and are only assumed to remove 35% TSS -See pp.19and 20 of the NC DENR stormwater BMP Manual, April 1999. 10% open water, 50% high marsh, 40% low marsh.