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HomeMy WebLinkAboutSDP201000035 Review Comments Preliminary Site Plan 2011-01-25*-&A County of Albemarle Department of Community Development Memorandum To: Gerald Gatobu, Current Development Project Planner From: Phil Custer, Current Development engineering review Date: 25 January 2011 Subject: West Village Preliminary Site Plan (SDP- 2010 - 00035) The second revision to the preliminary site plan for West Village, received 28 December 2010, has been reviewed. The plans have been significantly modified and additional comments are necessary. The following comments are provided: 1. The 100 -year floodplain should correspond to FEMA flood elevations within the study. The flood elevations shown within the study are to the North American Vertical Datum 1988 (NAVD 1988) and the site survey is said to have used the National Geodetic Vertical Datum 1929 (NGVD 1929). The site survey should be converted to NAVD 1988 to match the datum of the floodplain study. (For further information, please refer to the FEMA website.) Additionally, the floodplain limits should be revised as necessary to relate the elevations within the study to the site topography. In other words, at the locations shown on the FEMA study, match the 675, 680, 686, and 693 elevations to the contour lines of the site - specific survey and interpolate where appropriate. (Rev. I) Comment has been addressed. 2. This site is located within the watershed of the County maintained Lickinghole Creek SWM facility. Per Board policy, all development within this watershed must pay a pro -rata fee in exchange for the water quality treatment provided by the facility. The West Village project is not required to provide SWM quality onsite and County Engineering will not be reviewing the future WPO application for water quality requirement. The pro -rata fee will computed at the time of final site plan approval. 3. The only stormwater management requirements to be reviewed for this project will be detention of the 2 and 10 year storms to pre - development rates. This will be reviewed with the WPO application in conjunction with final site plan. Additionally, because of the considerable size of the watershed to Powell's Creek (- 2450acres) relative to the site (- 20acres), the County will likely look favorably upon a detention waiver if requested by the applicant per 17- 314.G. (Rev. I) The county engineer has conditionally granted a detention waiver: The plans meet the requirements for the detention waiver. This is granted with the condition that the channels to Powells Creek be examined for connections to the creek, such that erosion will not occur in future, either along the overbank area, or within Powells Creek itself. It appears efforts are being made to reduce runoff impacts from the site, and these playa part in the waiver of the 2 year storm requirements, which are designed to protect channels directly downstream. The plan must maintain at least the stormwater features proposed within the latest set or else be subject to reconsideration of the request. 4. If the ESC plan is not phased considerably, I see no alternative for the ESC plan other than a basin located within the 100 -year floodplain, which would require a Special Use Permit. I recommend revising the layout of development to locate a stormwater detention facility out of the floodplain and to make sure it is large enough to provide the proper ESC volume during construction. Otherwise, a sediment basin will be needed in the southeastern corner of the site and will likely Current Development Engineering Review Comments Page 2 of 4 consume much of the developable area of block 4. (Rev. 1) Comment has been addressed. The applicant intends to phase the development. This site generates more than 200 VPD and doubles the volume of traffic currently experienced by the existing road (Blue Ridge Avenue ADT 330). Therefore, the project requires a Traffic Impact Analysis (Chapter 527) before approval. (Rev. 1) The County Engineer offers the following comments on the Traffic Impact Analysis: A scoping document was not part of this report. As a result some things are unclear. 1. Does this development meet VDOT's connectivity requirements? 2. Does the volume from a connection (per 1) need to be considered? 3. Can off -site improvements be required? 4. Do the volumes from the build -out of Old Trail need to be incorporated? Depending on the answers to these questions, widening and upgrading of Blue Ridge Avenue (to the standards of Artists Way), as well as intersection improvements on Jarman's Gap road may be necessary. (Rev. 2) The traffic impact analysis has been approved by VDOT. 6. There is a considerable amount of vacant land northwest of this property. Once this land is developed to its full potential as currently zoned and a public road connection is made to Cling Lane, it is likely that the ADT for West Village Avenue will be greater than 2000 vehicles a day. The ADT would be higher if the Master Plan densities were used. Therefore, the road should be designed for an ADT greater than 2000 vehicles a day unless otherwise approved by VDOT. (Rev. 1) Comment has not been addressed. Despite the newly adopted Comprehensive Plan for the Crozet Development Area exhibiting lower densities for the parcels in question than the previous document, the by -right development of the parcels to the west with their existing zoning will likely cause Artist Way to experience daily traffic greater than 2000 vehicles. The projection by Renaissance Planning Group is not the highest possible volume as claimed on page 16 of their report. Several likely development scenarios exist that would result in an ADT higher than 2000 vehicles a day onto Artist's Way. Most notably, the 20 acres not in "developable area" cannot be discounted completely. There are several methods within the county ordinance that allows land owners to concentrate the development rights of the whole parcel into the developable area. For instance, the West Village application has an overall density of 5.95units /acre even though --35% of the property is within floodplain. Also, using the applicant's developable land assumption (27.6 acres could only be developed), if the properties to the west were developed with more than 13% of the units being single family detached homes, the ADT would be greater than 2000 vehicles a day. It is my understanding that VDOT is also requiring the road to be constructed to meet the 2001- 4000 ADT standard because the project has only one access point. To meet this standard, it appears that the roadway section for areas of one -sided parking must be expanded to 29ft (if approved by VDOT, otherwise the width must be 31 ft) and the horizontal curve will need to be flattened to a radius of 335ft. When the road construction plans are designed, please note that the sight distance and vertical alignment will need to be consider a design speed of 30mph. The current cross- section for Artist's Way with parking on one side has a discrepancy regarding the curb -to -curb width. (Rev. 2) The horizontal geometry of the roadway is adequate. The alignment of the road and additional 25' ROW to the paper alley on the adjacent property appear to be adequate to the Chief of Current Development regarding 14 -409. VOOT must approve the reduction of curb - to -curb width as allowed by note 9 on GS -SSR. County Engineering has no objection to the Current Development Engineering Review Comments Page 3 of 4 curb -to -curb width reduction. The vertical element of the road did not receive county engineering review. 7. Please show the construction of West Village Drive to the property line of TMP 56A1- 01 -31. [14- 409.B] The requirement may be waived by the agent. At this time, I do support the waiving of this requirement. (Rev. 1) As I hopefully clarified during the Site Review Committee Meeting, the last sentence in this comment was incorrectly written. I do not support the waiving of the extension requirement. This matter is to be considered by the Planner, however. It is my understanding that the road must be constructed to the adjacent property in order to meet VDOT's acceptance requirements. (Rev. 2) The alignment of the road and additional 25' ROW to the paper alley on the adjacent property appear to be adequate to the Chief of Current Development regarding 14 -409. 8. Please show the sight distance triangles for each entrance onto West Village Avenue. For the entrance closest to the end of the street show the sight triangle to the north on the existing platted ROW. (Rev. 1) The sight distance triangles have been shown and there appears to be no obvious obstructions. No further information is required for the preliminary plat with regard to sight distance. However, when the road plans are submitted, vertical profiles of the sight lines will be needed for Artist's Way looking both left and right onto Blue Ridge Avenue. 9. The swale will not work with the street trees in place. Please either request that the agent waive the street tree requirements in this area or remove the swale and replace with the standard 6ft planting strip. (Rev. 1) The water quality swale within the ROW has been removed, so the street trees can remain. However, the normal spacing requirement of 50ft should be followed when the road plans are submitted later. [18- 32.7.9.6] 10. The Water Quality Swale within the VDOT ROW will require the county to enter into an agreement with VDOT to assure its maintenance. The County will subsequently be required to enter into an agreement with the property owner to assure the swale's maintenance by the Homeowners association. I have some concerns with the current design, but because this BMP is not needed for county SWM requirements, the issue can be addressed during the final review of the plan. (Rev. 1) The water quality swale within the ROW has been removed. This comment has been addressed. 11. The Stream Buffer for this section of the county is 100ft from the edge of bank or the limits of the 100 -year floodplain, whichever is greater. (Rev. 1) Comment has been addressed. 12. If a retaining wall is needed adjacent to the intersection of West Village Ave. and Blue Ridge Ave., a guardrail will be required. This guardrail must be within the VDOT ROW. Please show the guardrail on the plan and adjust property boundaries and setbacks accordingly. I recommend removing the need for a retaining wall by providing a 3:1 slope to existing grade. (Rev. 1) Comment has been addressed. 13. The first entrance onto West Village Drive may be too steep and need to be revised during the final site plan. [ 18- 4.12.17] 14. The permeable paving will be reviewed during the final site plan stage once the section has been determined. However, pavers will likely need to be removed from all entrances onto the State ROW. 15. (Rev. 1) It appears as though a sidewalk is being proposed along existing Blue Ridge Avenue, which would be required by Planning through 18- 32.7.2.8 if not shown. Because the sidewalk is located in an area where a ditch would be, please provide curbing at the edge of the roadway when the road plans are submitted. The curbing will require a new drainage structure on Blue Current Development Engineering Review Comments Page 4 of 4 Ridge Avenue north of the intersection with Artists Way. This does not need to be addressed until the final application is submitted. 16. (Rev. 2) The Chief of Current Development is willing to use alley standards of the Subdivision Ordinance and Design Manual, including the 14ft width and lack of curbing, where alleys are shown on site plans. However, alleys are defined by the county ordinance as a travelway that provies access to the side and /or rear of lots. The travelway proposed by the applicant at the front of the Block B units does not meet this definition. Therefore, per 18- 4.6.3.d, a 25ft setback would be required from the 20ft easement of this travelway. Given this requirement and the floodplain at the rear of the property, the current alignment is unacceptable. 17. (Rev. 2) The parking lot in Block D must possess a travelway with a width of 24ft. The units within Block D must also be placed 25ft from the edge of this travelway to meet the setback requirements of 18- 4.6.3. [18- 4.12.16] 18. (Rev. 2) One way circulation must be contained completely onsite unless a waiver is granted by the Chief of Current Development. A VDOT maintained roadway cannot be used to complete a one -way loop. Please remove all notes indicating one -way travel. [18- 4.12.17.c.2] 19. (Rev. 2) The parking lot adjacent to the parcels to the north must be screened per 18- 32.7.9.8. It appears a screening fence at the top of the wall would be an acceptable alternative, since some safety measure will be needed at the top of the wall due to its height. No modification to the preliminary plan is needed to address this comment. This comment is provided at this time to note that a screening fence will be required at the top of this wall when the final site plan is submitted. Pitc: E3_psp_PBC_sdp201000035 Wcst Vitlagc.doc