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HomeMy WebLinkAboutSUB201000119 Review Comments Preliminary Plat 2011-08-30�'IRGINZ� COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: SUB - 2010 - 00119, Granger Property - Preliminary Plat Plan preparer: Mr. Scott Collins, PE; Collins Engineering Owner: Stribling Holdings LLC Date received: (Rev. 2) 1 August 2011 (Rev. 1) 15 November 2010 13 September 2010 Date of Comment: (Rev. 2) 30 August 2011 (Rev. 1) 28 December 2010 5 October 2010 Engineer: Phil Custer The second revision to the preliminary plat for The Granger Property (SUB- 2010 - 00119), received on 1 August 2011, has been reviewed. Engineering review can recommend approval to the plan after the following corrections are made: 1. This proposed preliminary plat shows significant disturbance to critical slopes. The applicant has included in his submittal package a waiver request to disturb these critical slopes. Engineering analysis of this waiver request will be provided in a separate document. (Rev. 1) Engineering analysis of this waiver request will be provided in a separate document. (Rev. 2) Critical slope disturbance has been reduced since the last submittal. A new engineering analysis of the disturbance will be provided in a separate document. The critical slope waiver analysis will recommend that the storm pipe at the end of Granger Way be moved so as to disturb less critical slopes. 2. The plan shows fill in the floodplain as being required. Since permission to fill in the floodplain can only be granted by the Board of Supervisors, the preliminary plat cannot be approved until the Special Use Permit(s) has been approved. The applicant should defer the preliminary plat until the fill in the floodplain has been authorized. (Rev. 1) The two special use permits for the floodplain stream crossings have been provided. Because the analysis of the special use permit applications require a detailed understanding of the preliminary subdivision plat, the county will process both applications concurrently. Engineering comments on the stream crossing special use permits will be provided in a separate document. (Rev. 2) Comment remains unchanged. 3. The Albemarle County Subdivision Ordinance requires that the public streets within a subdivision be coordinated "with existing or future planned streets within the general area of the subdivision" and "extended and constructed to the abutting property lines to provide vehicular and pedestrian interconnections to future development on adjoining lands." In the Comprehensive Plan, an Urban Collector Road is slated to connect Fontaine Avenue and Sunset Avenue Extended. The exact alignment of this collector road had not been determined by the Comprehensive Plan and had considered 4 options. However, the recently approved Zoning Map Amendment application for the Fontaine Research Park (ZMA- 2007 - 00013) has eliminated many of the anticipated routes. The University of Virginia Foundation proffered to eventually construct their portion of the Fontaine /Sunset Connector along the southern and eastern boundaries of their properties (see Exhibit D1 from ZMA- 2007 - 00013). In light of the general alignment of the northern section of this connector implicitly approved by the Board of Supervisors, Road A in the Granger Preliminary Plat must be extended to the existing Stribling Avenue railroad underpass to meet County Subdivision Requirements. [14- 409.A, 14- 409.B, 14 -429] (Rev. 1) There is still some confusion regarding the property boundaries around the stream crossings. I understand that the county planner for the project has requested or will be requesting that the applicant file for an official letter of determination from the Zoning Administrator regarding the location of the boundary lines. If the boundary is in fact the area delineated as "project limits" by the engineer, this comment may need to be modified. Otherwise, the extension of the roadway currently proposed on the plan requires significant permanent easements and ROW as well as temporary construction easements. These easements must be provided to the county before the preliminary plat can be approved. Please note that the Thomas Jefferson Planning District Commission is in the process of updating the traffic model for the county and the city. They expect to have results from their study by the end of March. Engineering review recommends that the application be deferred until input from the Thomas Jefferson Planning District Commission can be considered by staff. (Rev. 2) Comment has not been addressed. consent from the adjacent landowner(s) should be provided before these applications move forward. The Thomas Jefferson Planning District Commission appears to have dropped the update to the regional traffic model so additional input will not be given. Absent of this technical input, I recommend that the applicant request to schedule a work session for this project to discuss all remaining concerns and discretionary items. This should be done, however, once all third parties have signed off on the application (Dominion Virginia Power and the owner of the property to the northeast). 4. Because Road A is a portion of the Sunset - Fontaine Connector, its intersection with Sunset Avenue Extended cannot be perpendicular but must establish a through movement with a horizontal curve. The remainder of Sunset Avenue Extended (road to Eagle's Landing) must be modified to provide a perpendicular intersection with the Connector Road. Below is a screenshot of Alignment 4 (the most likely alignment) taken from the connector road study. The concept of the intersection of existing Sunset Avenue Extended should be mimicked, though the current location is acceptable. (Also, sight distance to the east appears to be an issue in the current proposed intersection configuration.) [14- 409.A, 14- 409.13, 14 -4291 (Rev. I) Comment has been addressed. 5. Based on the existing comprehensive plan, the Sunset - Fontaine collector should be classified as an Urban Collector and must meet the VDOT standards for such. (Rev. 1) This road should be designed based on the existing area B study which has a projected ADT of 4000 vehicles /day when this connection is made. The width of the lanes must be 12ft per GS -7. Also, CG -7 must be used per GS -7. VDOT may allow the use of the gutter as part of the bike lane. Please note that the Thomas Jefferson Planning District Commission is in the process of updating the traffic model for the county and the city. They expect to have results from their study by the end of March. Engineering review recommends that the application be deferred until input from the Thomas Jefferson Planning District Commission can be considered by staff. (Rev. 2) Comment has been addressed. The Thomas Jefferson Planning District Commission appears to have dropped the update to the regional traffic model so additional input will not be given. Absent of this technical input, I recommend that the applicant request to schedule a work session for the project to discuss all remaining concerns and discretionary items. This should be done, however, once all third parties have signed off on the application (Dominion Virginia Power and the owner of the property to the northeast). 6. Sidewalks and plantings strips are required on both sides of each new street within a subdivision of single family attached or detached dwellings within the development area. Please modify the plans to meet this requirement or request a waiver to the Planning Commission per 14 -422.E and 14- 422.F. Also, because Road A will be classified as an Urban Collector, VDOT clear zone requirements may be problematic. Five foot wide bicycle lanes and eight foot wide plantings strips were a solution to this issue with another development with an Urban Collector. [14 -422] (Rev. 1) A request has been provided to the Planning Commission and will be reviewed with the Special Use Permits. There may be lateral offset issues with the proposed road cross - section. (Rev. 2) Comment remains unchanged. There may also be some issues with the cross - section /ROW width regarding the need for guardrail for a significant portion of Road A, but especially near the stream crossings. Please correctly label the deedbook and page number for the property each time it is referenced. (Rev. 1) There is a discrepancy between the DBs on sheets l and 2 for the parcel. (Rev. 2) Comment has been addressed. The topography within the survey must use the same vertical datum of the FEMA maps. The flood elevations shown within the FEMA study are based on the North American Vertical Datum 1988 (NAVD 1988) and the site survey is said to have used the North American Datum 1983 (NAD83), which is defined as a horizontal datum by NOAA. The vertical datum for the site survey appears to use a benchmark that is a nail in a tree deep within the site. The site survey must be converted to NAVD 1988 to match the datum of the floodplain study, if it is not already. 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 408, 410, 413, 414, 418, and 422 elevations to the contour lines of the site - specific survey and interpolate where appropriate. (Rev. 1) Comment has been addressed. 9. The Subdivision Ordinance requires that the contour interval for the topographic data in the survey and proposed contours be at an interval no greater than the county supplied data. The current county supplied data is at an interval of 4ft. The topographic information within the plat (existing and proposed) must be converted to 4ft contour intervals. [14- 302A.12] (Rev. 1) It appears as though 4ft contours are now being used. However, please correct many of the contour labels and add more. (Rev. 2) Comment has been addressed. 10. I have evaluated the stream along the southern boundary of the property using an abbreviated version of CBLAD's "Determination of Water Bodies with Perennial Flow" and determined that it is perennial. This stream requires a 100ft buffer from each bank from the existing Moore's Creek buffer to the interstate culvert. If the applicant wishes to dispute this determination, a full assessment must be made following Fairfax County's "Perennial Stream Field Identification Protocol, May 2003." [17- 104, 17 -317, 14- 302.B.101 (Rev. 1) Comment has been acknowledged by the applicant. 11. Outside of the Rural Areas and Water Protection Watersheds, the stream buffer is 100ft from the edge of the stream irrespective of the 100 -year floodplain. [17 -317] (Rev. 1) Comment has been addressed. 12. Per 17- 320.D.6, one stream buffer crossing is allowed for each parcel by -right. Due to the interconnectivity requirements for this parcel, the Program Authority will authorize two crossings in addition to the by -right crossing: one for crossing the stream running parallel to Sunset Avenue Extended, one for the current proposed Road B crossing, and one for the crossing required by comment 3. The Program Authority will also allow the discretionary 50ft of landward buffer disturbance shown on lots 75 and 76. Other disturbances of the landward 50ft of stream buffers will be considered during the more detailed review of the ESC, Road, and SWM plans. Mitigation will be required for all stream buffer disturbances (private laterals, roads, grading, ESC measures, etc.) allowed within the buffer. The placement of stormwater facilities and publicly maintained utilities are exempt from stream buffer mitigation requirements, though engineering review maintains the authority to modify the footprint and alignment of these items to minimize disturbance within the buffer as much as practical. [17 -319, 17 -320, 17 -321] (Rev. 1) Authorization into the stream buffer will be reviewed with the mitigation and esc plans after preliminary plat approval. Some grading may need to be modified. (Rev. 2) Comment has been acknowledged by the applicant. 13. For the local subdivision streets, a curb to curb width of 29ft is needed for parking on both sides of the street. The current proposed 28ft wide road is acceptable for Roads B, C, D, and E, but parking on both sides may not be allowed by VDOT. (Rev. 1) Comment has been acknowledged by the applicant. 14. It appears that a fire truck will not have access from the public streets to most buildings on lots served by the alley. The alley may need to be designed to accommodate a fire truck. The final determination and the necessary standards should be discussed at the site review meeting with the Assistant Chief, James Barber. [14- 410.D] (Rev. 1) The Assistant Chief has approved the alley section as adequate for emergency vehicles. 15. Please provide a letter of intent showing that the owner of TMP 7613-1 and 7613-2 will grant the necessary ROW and easements to complete this project. (Rev. 1) Due to the level of involvement by the Planning Commission and Board of Supervisors on this project, the offsite easements must be recorded prior to preliminary plat approval. If these easements cannot be obtained, the project would look radically different and legislative decisions may not be the same. (Rev. 2) Comment has not been addressed. 16. Please provide a letter from Dominion Virginia Power that indicates they will permit the proposed roads, grading, and pole reconstruction shown in the current plan. (Rev. 1) Comment has not been addressed. (Rev. 2) Comment has not been addressed. 17. Please provide the County's modified simple spreadsheet for each BMP. [14- 302.A.13] (Rev. 1) Comment has not been addressed. (Rev. 2) Comment has been addressed. However, SWM Facility #4 captures a lot of undeveloped area. This facility may need to be located offline into the eastern hillside. Engineering review will evaluate this facility when the Water Protection Ordinance application is submitted at a later date. 18. A Stormwater facility is needed at the rear of lots 27 and 28. The current SWM concept plan proposes the installation of a drainage pipe 40ft below existing grade (intersection of roads C and D) which is not practical. BMP's must also be sited to reasonably maintain existing drainage patterns. [17 -312, 14- 302.A.131 (Rev. 1) Comment has been addressed. This facility will be commented on in the critical slope waiver analysis. 19. The location of pond 1 is not practical. The facility must be placed downhill of the culdesac. [17 -312, 14- 302.A.131 (Rev. 1) Pond 1 should be located in Lot 11 where there is a natural valley. (Rev. 2) Comment has been addressed. 20. A sediment trap or basin will be needed at the rear of lot 13 when the ESC plan is submitted. It is feasible that this facility be converted to a BMP to treat the driveways and lots of 12 -18. Please show this facility on the plan. [17- 312.C, 14- 302.A.13] (Rev. 1) Comment has not been addressed. (Rev. 2) Comment has been addressed. 21. Around the stream crossing, please provide a BMP to capture the half of Road B that is currently not treated. [17- 312.C, 14- 302.A.13] (Rev. 1) Comment has not been addressed. The watershed for Pond 5 is not feasible based upon the proposed elevations. Pond 5 also disturbs much of the stream buffer and critical slopes. A facility east of the intersection of Sunset Avenue Extended and Stribling Place appears to be ideal. (Rev. 2 ) Comment has been addressed. 22. Each of the three stormwater facilities are described as ponds which is acceptable for preliminary applications because such facilities can be designed for a broad range of removal rates (35 % -65 %). However, the small drainage areas and placement of the facilities outside of natural drainage ways will make each facility susceptible to dry weather drawdown. When the SWM plan is submitted, drought condition drawdown calculations will be required. 23. (Rev. 1) The trail should be directed to the existing Stribling underpass, not the stream culvert. (Rev. 2) Comment has been addressed. 24. (Rev. 2) Phase I must include the connection to the Stribling Ave. railroad underpass. [14 -409, 14- 410, 18- 32.7.2.4] 25. (Rev. 2) Since 90% of all traffic will be turning left onto Granger Way from Granger Place, please replace this full stop with a horizontal curve. [14- 410.A] 26. (Rev. 2) The sidewalk along Sunset Avenue must be within the ROW. 27. (Rev. 2) The Stribling Avenue intersection with Sunset Avenue Extended will need significant changes to the proposed grading. Existing Stribling Avenue will need to be regraded and upgraded significantly to the east to achieve adequate road slopes. Please show this grading on the plan, as had been done in the second submittal of the preliminary plat. 28. (Rev. 2) A pedestrian connection from the culdesac of Granger Way to Sunset Avenue Extended might be beneficial for residents of this subdivision. There is nothing within the subdivision ordinance that obligates that this connection be made. However, staff will identify this need within the staff report and recommend it as a condition on the acceptance of the open space for the greenway. 29. (Rev. 2) The alignment of the greenway trail should be adjusted so that it can meet Class A Type 2 standards. The trails should meet ADA standards and not rely on stairways. 30. (Rev. 2) Please adjust all lot lines so that all trails and stormwater facilities are out of privately owned lots. File: E3_ppt_PBC_SUB- 2010 -00119 Granger Preliminary Plat.doc