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HomeMy WebLinkAboutSUB201300091 Review Comments Road Plan and Comps. 2013-07-11�� OF A i" A COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: Cascadia Blocks 4 -7 SUB201300091 Plan preparer: Dominion Engineering [434- 979 -8121] Owner or rep.: Redus VA Housing, LLC Plan received date: 26 June 2013 Date of comments: 11 July 2013 Reviewer: Michael Koslow Review Coordinator: Michael Koslow The first submittal of the road plan set (SUB201300091) submitted 24 June 2013 has received Engineering Review and does not appear to meet Albemarle County minimum checklist items for approval. This review does not include a review of Erosion & Sediment Control, Mitigation, or Stormwater Management. Please adequately address the following comments for final approval: A. Application Information 1) A 12' tall retaining wall and two 8' tall retaining walls are proposed on sheet SP 10. The Code of Development for Cascadia p. 24 states that walls over 6 -feet tall, as measured from top of wall to the top of the footer, shall be allowed only at the discretion of the Director of Community Development. Per correspondence with the Director on 7/10/2013: a. The Department finds the 8' tall wall proposed behind Lots 56 -58 acceptable with any material. b. The Department does not find the 12' wall and other 8' wall proposed in the Vegetative Buffer along the property line for Fontana Subdivision acceptable pending any potential stream buffer incurrence (see comment B2). It is imperative to keep grading outside of the 30' Vegetative Buffer. Two alternative options available for these walls are: 1. A green wall (with vegetation in front of the vegetative buffer) of maximum height 20' located outside of the vegetative buffer (preferred option). 2. A series of terraced walls of maximum height 6' located outside the vegetative buffer. Because they are visible from the street, these walls should be made of a higher material quality (finished with brick, interlocking concrete block or stacked fieldstone per p. 24 of the Code of Development). See also comment D2 regarding the proposed retaining walls. 2) Per ZMA2002 -00004 proffer #5, please submit an overlot grading plan showing existing and proposed grading for this project. This could coincide with a road plan or site plan submittal but is needed for proposed subdivision. Engineering Review Comments Page 2 of 4 B. Existing Plan View Information 1) Please label all existing contour elevations including those shown on detail 1 on sheet SP8 as well as for proposed lots 79 -84 on sheet SP8. 2) An unnamed tributary to Rivanna River appears to run behind east end of project. Please include a stream analysis to determine if this stream is a perennial or intermittent stream. C. Proposed Plan View Information 1) Some traffic signs appear to be missing including: Stop sign at the the corner of Boulder Hill Lane and Delphi Lane Label for stop sign at the corner of Oval Park Lane and Delphi Lane Stop sign at Glissade Lane and Delphi Lane Labels for stop signs at ends of Flat Waters Lane Speed limit signs throughout the development Street name signs throughout the development Please include all required traffic signs on proposed road plans. 2) Please label all proposed contour elevations including those shown on detail 1 on sheet SP8 as well as for proposed lots 79 -84 on sheet SP8. 3) Please specify by area in landscape plan low maintenance ground cover for all proposed slopes steeper than 2:1. Please also note requirements of Proffer 5 from ZMA2002 -00004 for low maintenance plantings. 4) Please label all entrance and intersection radii including the corner of Glissade Lane and Delphi Lane on sheet SP 10. 5) Please label all proposed drainage easements including the proposed easement for pipe out of proposed structure 7C crossing proposed lot 1 on sheet SP6. 6) Proposed drainage easement for pipe out of proposed structure 7E crossing proposed lot 4 on sheet SP7 appears to be 10' wide. Please propose a minimum width of 20' for all proposed drainage easements. 7) Please confirm proposed parking lot curb type (appears to be CG -2) on sheet SP7. 8) Please widen sidewalk in front of proposed neighborhood center from 5' to 6' or provide bumper blocks for adjacent parking spaces on sheet SP7. 9) Please include stationing for all proposed streets at minimum 50' intervals. 10) Please label all PCs and PTs for all proposed streets. 11) Please label the maximum (not average) height for each proposed retaining wall. 12) A retaining wall appears to be shown on sheets SP6 and SP 10. Please label all retaining walls on all sheets on which they appear. Engineering Review Comments Page 3 of 4 13) Sheet SP38 appears to be part of the landscape plan. Please update sheet name. D. Plan Detail Information 1) Please specify 3000 psi strength requirement and 4" stone base for all proposed sidewalks on road typical sections. 2) Please provide a typical retaining wall detail for each proposed retaining wall. Please note per code of development p. 24, retaining walls visible from the street or other public areas (which include both proposed retaining walls as designed) shall be of a higher material quality and shall be compatible with the adjacent building architecture materials and /or colors. 3) Please include Albemarle County General Construction Notes for Streets. E. Street Profiles 1) Please label existing and proposed grade at each 50 feet. 2) Please indicate proposed drainage structures on road profile sheets. 3) Please include cross drains (CD -1 or CD -2) at cut -fill transition points. 4) Please indicate road intersection stations in profile view. F. Street Details 1) Please propose a pavement design on typical sections for each public and private road proposed which supports proposed traffic loadings per 2009 VDOT Pavement Design Guide for Subdivision and Secondary Roads in Virginia or equivalent. 2) Please specify 3000 psi strength requirement and 4" stone base for all proposed sidewalks on road typical sections. 3) Please propose a transition detail for roll top curbing proposed for Oval Park Lane at proposed drainage structures. G. Drainage Profiles 1) The following structures appear in plan view but appear to be missing in profile view: 16, 17, 19, 20, 21, 23, 24, and 44A. Please include drainage profiles for all proposed drainage structures. 2) Please label existing ground and proposed ground elevation lines on all drainage profiles including profiles for two proposed drainage structures. Engineering Review Comments Page 4 of 4 3) The following pipe runs appear to have utility conflicts as indicated in plan view (w = water line, s = sanitary sewer line) but the conflicting utility pipes appear to be missing in profile view: 2 -3(w), 2 -3(s), 34(s), 10- 11(s), 14- 15(s), 15- 16(w), 22- 23(s), 23- 24(w), 24- 25(w), 44- 44A(w). Please include all utility conflicts for all proposed drainage structures in profile view. 4) Station for structure 49 appears to be missing. Recommend including this station with drainage profile on sheet SP29. 5) The following pipe run appears to have a slope > 16 %: 6213-62C. Please include anchor blocks for all proposed pipe runs with slopes > 16 %. 6) Please prescribe by note or on the profile that concrete Inlet Shaping (IS -1) shall be included for all proposed drainage structures with a 4' or greater drop. 7) Please prescribe by note or on the profile that Safety Slabs (SL -1) shall be included for all proposed drainage structures taller than 12'. 8) Please include scour protection for all outlets in profile view, corresponding to computations and protection shown in plan view. H. Drainage Computations 1) Due to overwhelming VDOT comments, it is assumed the drainage will be re- worked for this project at resubmittal. Conceptual review includes the following missing items which county engineering will be looking for at resubmittal: a) Please ensure principal access (proposed structures 66 & 67) is free from flooding during a 100 year storm event. b) Spread for all inlets need to be checked for 4 in/hr intensity per VDOT Drainage Manual Table 9 -1. c) Inlet efficiency needs to be checked for 6.5 in/hr per note 4 attached to VDOT Drainage Manual Table 9 -1. d) Pipe capacities for proposed enclosed drainage (including proposed yard drains which feed into street trunkline systems) need to be checked for a 10 -year storm event at duration equivalent to time of concentration (this appears to be included for currently proposed system on sheet SP31 pending comment F 1 e below). e) Please include time of concentration of drainage area maps shown on sheets SP32 & SP33 (this information appears to be on calculations shown on sheet SP31A). Community Development Engineering is available from 2:30 -4 PM on Thursdays to discuss these review comments. Please contact Michael Koslow at 434 - 296 -5832 ext. 3297 or email mkoslowAalbemarle.or to schedule an appointment. File:C:\ Users \mkoslow\ Documents \CurrentReviews \SUB201300091 Cascadia Blocks 4 -7 - Road Plans \El RP MAK SUB - 2013 -00091 Cascadia Blocks4 -7 Road.doc