HomeMy WebLinkAboutWPO200700098 Review Comments Stormwater Management Plan 2008-04-28ALg�,��
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COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Phone (434) 296 -5832 Fax (434) 972 -4126
Project: Greer Elementary School Addition, Major Site Plan Amendment
(SDP- 2007 - 00121, WPO- 2007 - 00098)
Plan preparer: Mr. Francis Slinsky, PE fax: 919.859.5663
Timmons Group
Owner or rep.:
Date received:
Date of Comment:
Lead Engineer:
County of Albemarle School Board
fax: 434.975.9341
Rev. 3: 24 March 2008 (plans signed 21 March 2008)
Rev. 2: 24 January 2008 (plans signed 22 January 2008)
Rev. 1: 26 November 2007 (plans signed 20 November 2007)
22 October 2007 (plans signed 19 October 2007)
Rev. 3: 28 April 2008
Rev. 2: 4 March 2008
Rev. 1: 17 December 2007
13 November 2007
Phil Custer, Engineer
The WPO plan for the Greer Elementary School Addition, received on 24 March 2008, has been reviewed.
Engineering review for current development will grant approval to the plan once the following items have
been addressed.
A. Final Site Plan comments; SDP - 2007 - 00121:
All comments have been addressed.
B. Stormwater Management Plan comments; WPO- 2007 - 00098:
All comments have been addressed.
C. Erosion and Sediment Control Plan; SDP - 2007 - 00098:
15. There are inadequate perimeter controls for the initial site clearing and land disturbance with
existing topography. Many of the E &S measures cannot even be installed until grading is
complete. For example, the diversion at the north end of the site cannot be constructed until final
grade is established and the silt fence at the base of the fill slope would most likely be washed out.
The erosion and sediment control plan appears to need at least two phases.
f. (Rev. 2) Sheet C2.1 states the maximum area to the sediment trap is 2.9 acres but when
the storm sewer is installed, the area will be at least 3.4 acres (according the SWM
calculations). Please clarify.
(Rev. 3) A sediment basin has replaced the sediment trap. It does not appear
that there is at least one foot of freeboard between the height of the 25 -year
storm and the top of the embankment. It looks as though at the 527.50 elevation,
the riser has a capacity of close to 7cfs and cannot handle the 25 -year storm
without the use of the emergency spillway. A routing also confirmed this. The
calculations also show that baffles are required but none are present in the plan.
h. (Rev. 2) In sequence I of the ESC plan, please remove the demolition designation from
the site elements that are to be saved until phase H of the building construction. I
suggest removing the hatching in this area, adding the safety fence from sheet C1.1,
and modifying the limits of construction on Sheet C2.1.
(Rev. 3) It appears sheet C2.1A should come before sheet C2.1 in the sequence of
construction. All other phasing issues have been addressed.
D. Additional WPO and site plan comments based on revisions to latest plan:
25. (Rev. 2) For all slopes steeper than 3:1, please specify a low- maintenance ground cover.
(Rev. 3) Comment not addressed. The groundcover cannot be grassy.
File: E4_fmj swm esc_PBC_GreerElementaryAddition