The URL can be used to link to this page

Home My WebLink AboutSUB202000190 Review Comments Preliminary Plat 2021-01-05� AI �h �lRGIN�P COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902-4596 Phone (434) 296-5832 Fax (434) 972-4126 Subdivision Plan Review Project title: Slabtown Meadow Preliminary Plat Project file number: SUB2020-00190 Plan prepares Shimp Engineering, Justin M. Shimp [ iustin e shimp-engineering.com ] Owner or rep.: John W. or Agnes J. Anderson /P.O. Box 10, Crozet, VA 22932 Plan received date: 23 November 2020 Date of comments: 4 Jan 2021, rev 5 Jan 2021 Plan Coordinator: Christopher Perez Reviewer: John Anderson SUB2020-00190 C1 1. Stormwater Management Note indicates post -developed runoff will be entirely sheet flow. a. Provide detail, how this is to occur, specifically. Consider /discuss SWM water quality requirements, and how proposed subdivision proposes to meet requirements at 9VAC25-870-65. b. Consider and discuss concentrated roof leader line discharge, how this converts to sheet flow. c. Clarify that subdivision proposes forest /open space easement, to credit post -developed forest /open space land cover in VRRM.xls, and thereby reduce phosphorus reduction requirements. d. Submit WPO Application at earliest convenience. i. WO plan must be approved prior to final subdivision plat approval. ii. FOS easement (if proposed) may be recorded with the final plat. iii. Ensure no fill within 100 yr-floodplain. iv. Ensure grading /proposed subdivision is consistent with permitted and prohibited uses and structures table (18-30.3.11). 2. Source of boundary and topography: Revise note to include survey date and name of the licensed professional; or a statement that topography data provided by the county was used. Also, field verification of topography within the last 12 months is required, if date of survey is not within the last 12 months. 3. Revise Floodzone Note to reference May 16, 2016 (FIRM), rather than Feb. 04, 2005 ( see 18-30.3.2). C2 4. Show Ex. tree line. 5. Label Lickinghole Creek. 6. Show Ex. OB P /overhead telephone. 7. Increase pitch, Crozet Ave. /other labels, so readable C3 8. Shift TMP 56-37 label so that property owner data is readable. C4 9. 14-302.A.6: provide dimensions and locations of easements for shared driveways that extend to edge of pavement, Crozet Avenue. VDOT will not maintain private shared driveway entrances within public RW. 10. Label all entrance widths (Lots 1-7) at their narrowest point, whether narrowest point occurs within or beyond public RW. 11. Provide existing contour labels, Lots 1-7. Engineering Review Comments Page 2 of 3 12. Provide sight distance easement/s for entrances, wherever required, across lots. Sight distance easements may be recorded with the final subdivision plat. 13. Label stream buffer, which appears coincident with horizontal limits of the 100-yr floodplain. 14. 14-302.A.12: Provide proposed grading required to evaluate drainage, elevations, etc. Additional comments are possible. 15. Provide existing and proposed spot elevations to aid review of improvements, FEE, etc. relative to Floodplain BFE. 16. Show and label existing San. Sewer improvements within Crozet Avenue public RW, if proposed 8" sewer pipe is to connect with an existing sanitary sewer within Crozet Ave. RW. C4 is ambiguous. It is unclear whether sanitary effluent is to route to Crozet Ave., or to Ex. 30' wide San. Easement on Lot 1. Please clarify sanitary sewer design. 17. Provide deed bk.-pg. ref. for existing sanitary and ACSA WL easement/s beyond public RW. 18. Provide note with final plat that no improvements may be constructed within floodplain or stream buffer (at County Engineer request, per ordinance). 19. Provide sanitary sewer profile. Ensure any portion of proposed sanitary sewer within floodplain is watertight, with lids elevated above base flood elevation per county /ACSA construction requirements. 20. 14-302.A.13: Stormwater Management Note indicates structural measures are required to convert post - developed concentrated runoff from impervious surfaces (roof leader lines, for example) to sheet flow. Revise plat to show /label proposed drainage and SWM facilities (level spreaders /riprap, for example), and related improvements. 21. With WPO Application, provide detail sufficient to demonstrate compliance with state SWM quality /quantity requirements. 22. Ensure revised preliminary plat meets 18-30.3 requirements for permissible use or activity within mapped floodplain. 23. Recommend revise sheet title to Site Layout since this is not a site plan. 24. Provide a grading plan. Grading plan must identify offsite borrow or waste areas. At a minimum, grading plan should include: a. Existing grade b. Proposed grade c. FFE, for each structure (single-family home) d. Basement floor elevation, each structure [ see 14-302.B.9 ] e. Cut /fill balance, or narrative, to give preliminary indication of import /export. 25. Provide Aabel ACSA utility access easement. If ACSA utility access easement is across Lot 6, please label so that owner of Lot 6 is reasonably notified /able to anticipate movement of equipment across easement, across lot. 26. Shift location of structure on Lot 7 to provide minimal clearance, outside stream buffer and floodplain, to construct single-family dwelling. Location of structure on Lot 7 touching 100-yr floodplain and stream buffer cannot be approved, proposed location does not provide adequate area for construction, while simultaneously avoiding stream buffer /floodplain trespass. 27. Shift location of structure on Lot 6, for the same reason. 28. 14-302.A.9: Show Aabel location, area and dimensions of a building site on each proposed lot complying with the requirements of section 18-4.2. 29. Engineering has no objection to request for variation from Sec. 14404(A). Letter d. 11/20/20 requests a variation from requirements of Section 14-404(A), which requires a single point of access on the lot from one street, shared driveway, or alley established at the same time as the original subdivision. The letter request states: `The subdivision plat for Slabtown Meadows proposes the creation of seven (7) single family home lots from the 7.41 acre parent parcel that is zone R-1 Residential. A considerable portion of the parent parcel is designated as stream buffer and floodplain, however there are approximately two acres of the parcel adjacent to Crozet Avenue that do not contain environmentally sensitive features and that can accommodate seven (7) building sites.' The letter further states: `The proposed design has considerably less impervious surfaces when compared to a design that accommodates internal road infrastructure that would be required to provide a single point of access to the subdivision ... The design of the proposed Engineering Review Comments Page 3 of 3 Slabtown Meadow will establish seven (7) by -right residential lots that effectively make use of the developable portions of the parent parcel while minimizing disturbance in areas designated as environmentally sensitive features and further respecting those environmentally sensitive features by minimizing the amount of impervious surface needed to access the proposed lots by designing them to be accessed by a series of shared driveways.' Engineering concurs. Further, shared driveway design and proposed development may meet stated goal of post -developed sheet flow of storm runoff as opposed to concentrated runoff anticipated with road construction, with typical storm runoff capture and conveyance. 30. Please clarify intent of showing a BFE line that varies from GIS limits of 100-yr floodplain. Ordinance keys to flood hazard overlay district visible as shaded linework (areas) in county GIS. It is unclear what is meant or proposed by including a solid dark line labeled BFE on C4. For example: Does this solid dark boundary originate with 2016 FEMA FIRMS? Please feel free to call if any questions. Thank you J. Anderson 434.296-5832 -x3069 SU B202000190 Slabtocan Meadow 010521rev pre]implat