Loading...
HomeMy WebLinkAboutWPO201100010 Review Comments WPO VSMP 2011-04-01 (2)COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 229024596 Phone (434) 296-5832 Fax (434) 972-4126 Project: Old Trail Village — Block 23 ESC Plan [WPO-201 1-000 10] Plan preparer: Mr. Scott Collins, PE; Collins Engineering Owner or rep.: March Mountain Properties LLC Date received: 16 February 2011 (Rev. 1) 13 May 2011 (Mitigation Plan Received 18 May 2011) Date of Comment: 1 April 2011 (Rev. 1) 8 June 2011 Engineer: Phil Custer The first revision to the Erosion & Sediment Control plan for Old Trail Village Block 23 (WPO-2011- 00010) has been reviewed. A plan was submitted on the 191' of April but no review payment accompanied it. Around the time of the payment, a new plan was submitted, received 18 May 2010. This latest plan was the one reviewed by engineering. The plan can be approved after the following comments are addressed. Inlet protection is not a sufficient primary measure for sediment control in Phase II of the ESC plan. Inlet protection is intended as a supplemental measure with a sediment trapping measure at the end of the pipe. Please modify the plan and construction sequence so that an appropriately sized sediment trapping measure is provided at the end of pipe in phase 2 of the ESC plan. The existing stormwater pond cannot be converted to an ESC basin. I recommend moving sediment trap 1 (or perhaps combining both traps) 150ft to the west and rerouting the storm pipe through this point. After the site is stabilized, this trap can be removed and a riprapped channel to the pond can be constructed. Additional comments may be necessary due to the required conceptual change. The disturbance to the stream buffer appears to be unavoidable given the approved rezoning plan and it will be authorized per 17-321.6. However, this authorization will require an approved and bonded mitigation plan, which can be easily accomplished between the existing pond and units 6, 7, and 8. I also acknowledge that the redesign of the pipe system will shorten the flow path for this pond. Since the site makes up such a small percentage of the total watershed and the application plan only required Block 23 drain to a detention pond, a shortened flow path will be allowed. (Rev. 1) Trap 2 cannot be constructed as shown withoutfilling over the existing outlet from Golf Drive. Please either include the new storm drainage system (EXS.S-OUT) in Phase I and mention its construction in step 4 of the construction sequence or revise the grading for this trap so that the existing outlet is not disturbed. In step 7 of the construction sequence, reference sediment trap 2, not the existing old trail pond All other modifications to the ESCplan are acceptable. 2. Please provide an approval letter from DEQ consenting to the proposed disturbance for the construction of a storm pipe within their existing conservation easement. Also, the recorded document referred to in the "existing drainage easement' note (DB 3745 PG 672) does not delineate any drainage easement. This document appears to be solely concerned with water and sewer easements. (Rev. 1) Comment has been addressed The storm pipe has been revised so disturbance to the DEQ easement is no longer necessary. The drainage easement deedbook has been corrected 3. Please show the grading and ESC measures necessary to connect the proposed sidewalk to the existing sidewalk constructed with the road. This disturbance will also need to be authorized by DEQ. (Rev. 1) The Chief of Current Development and current development planner have approved the 5ft asphaltpath note as is. No review of ESC measures can take place when the alignment of a path does not need to be designed as per their determination. The ESC inspector will need to review the construction in the field to make sure state law is met I will add the estimated limits of disturbance for the construction of this path into the ESC bond 4. A soil map does not appear to have been provided. (Rev. 1) The soil map provided does not match the current USDA map. Soil type 26C3 does not exist around this site. 5. The soil descriptions in the ESC narrative do not correspond to the soil types encountered on this particular site. Please correct. (Rev. 1) Soil type 260 does not exist around this site. 6. Please provide an updated list of the county's ESC notes on ESC-1. These can be found in the latest edition of the design manual (updated 12 February 2010). (Rev. 1) Comment has been addressed 7. Please provide a location for a soil stockpile for the topsoil that will be removed at the beginning of construction activities. The stockpile should be out of the way of general construction activities. (Rev. 1) Comment has been addressed 8. Please provide outlet protection for all drainage system outfalls. (Rev. 1) Comment has been addressed 9. The area of disturbance stated in the ESC narrative does not match ESC-2 and ESC-3. (Rev. 1) Comment has been addressed 10. Please remove the previously approved SWM sheets from this set to avoid confusion in the future. The Stormwater Runoff note on sheet ESC-1 should be updated to refer to the application number of the previously approved plan that accounted for the detention of Block 23. A Pro-Rata share to the Lickinghole Basin will need to be paid as well. This fee will be calculated at the time of plan approval. (Rev 1) Comment has been addressed The Lickinghole Basin Fee for the project has been computed to be $3,893.92. If this fee is not paid before January 1 S12012 or if the design changes significantly, it will need to be recalculated 11. Once all plans have been approved, please provide a completed Bond Estimate Request Form to the county engineer to receive an ESC bond estimate. (Rev. 1) Comment remains unchanged 12. (Rev. 1) Boulders must be removed from the emergency spillway of the adjacent stormwater pond Please include this work in the limits of disturbance and construction sequence of this application. A mitigation plan and fee were received by the county on the 18 May 2011. The following comments pertain to the mitigation plan. 1. The mitigation plantings cannot be placed over the emergency spillway or embankment. Please move the 16,197sgft of mitigation plantings to another location. [VSMH 3.03] 2. This comment is only advisory. It appears the western mitigation area has been specified in an area that will obstruct a tee shot of one of the holes after 5-10 years. 3. Please specify the number of seedlings in each of the mitigation areas. 4. A document that looks like an easement plat accompanied one of the site plan resubmitals. For county purposes, I don't think this document is necessary. I will use the Landscape sheet Ll as the mitigation plan to be kept in the county records. If an easement plat is needed by the owner(s) for the mitigation areas, please submit these documents again with a subdivision application and the appropriate fees to Megan. 5. Once all plans have been approved, please provide a completed Bond Estimate Request Form to the county engineer to receive a mitigation bond estimate. File. E2 esc PBC WPO-2011-00010 Old Trail Block 23 ESC Plan doc