HomeMy WebLinkAboutWPO201200070 Review Comments Erosion Control Plan 2013-03-11i"
,. `IRGINZP
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: Whitewood Road Day Care Center Amendmentl (WP02012- 00070)
Plan preparer: Pohl Consulting LLC [tel 434- 466 -7458]
Owner or rep.: University of Virginia Physicians Group
Plan received date: 25 January 2013
Date of comments: 11 March 2013
Reviewer: Michael Koslow
The first erosion and sediment control and stormwater management plan submittal of the first
amendment to approved WPO plan (WP0201200070) submitted 25 January 2013 has received
Engineering Review and does not appear to meet Albemarle County minimum checklist items for
approval. Please adequately address the following comments for final approval:
A. Existing Conditions Information
1) Please indicate source of existing invert elevation for drainage structure "EX.ST -2 ". Per sheet C -2
of WPO plans approved on 10/26/2012, it appears the outlet elevation is 573.70 based on
topographic survey from 10/2006. However, amended drainage profile on sheet C -5 indicates the
existing outlet elevation for "EX.ST -2" is 573.59.
B. Erosion and Sediment Control Plan
1) Please include inlet protection for inlet "EX.ST -2" on sheet ESC -3.
2) Please provide an adequate channel analysis for runoff from proposed construction. Analysis needs
to be carried further downstream compared with submitted MS -19 computations submitted
1/25/2013. Analysis could be proven given:
a) adherence to VESCH MS -19 requirements (see 4VAC50- 30 -40, MS -19 sec. b (1)): The
applicant shall demonstrate that total drainage area to the point of analysis within the channel
is one hundred times greater than the contributing drainage areas of the project in question. A
report or plan depiction with analysis to this point could prove channel adequacy.
b) adherence to VA code 10.1- 603.4(7): essentially, the required condition for an on -site
solution without looking downstream for a 24 hour 1.5, 2, and 10 -year intensity event -
(post - development) Peak flow rate <= Pf *Vf/Vp
Where Pf = peak flow rate in a forested condition
Vf = runoff volume in a forested condition
Vp = runoff volume proposed
Engineering Review Comments
Page 2 of 2
C. Stormwater Management Plan
1) Please revise label "STR102 — STR EX.ST1" label on sheet C -5 to "STR102 — STR EX.ST2 ".
Current 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 mkoslow @albemarle.org
to schedule an appointment.
[17- 204.f] An application for an erosion and sediment control plan that requires modifications, terms, or conditions to be
included in order for it to be approved shall be deemed to be withdrawn if the owner fails to submit a revised plan addressing the
omitted modifications, terms or conditions within six (6) months after the owner is informed of the omitted information as
provided under paragraph (B).