HomeMy WebLinkAboutWPO200800090 Review Comments Stormwater Management Plan 2008-10-13Phone (434) 296 -5832
4126
Project:
Plan preparer:
Owner or rep.:
Date received:
Rev.l:
Date of Comment:
Rev.l:
Engineer:
IRGINZ
COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Fax (434) 972-
WPO- 2008 - 00090, Western Albemarle High School Boathouse
Mr. Craig Kotarski; Timmons Group
WAHS Boating Club
3 Sept. 2008
2 Oct. 2008
22 Sept. 2008
13 Oct. 2008
John Diez
A. General Review Comments
craig.kotarski@timmons.com
+ is incorrect. Please provide the correct number, which is:
ID# 05700 -00 -00 -00400 (not 05700- 00 -00- 04000).
(Rev. I) Comment has been addressed
B. ESC Plan Review Comments
1. A site visit performed by County staff found that very little drainage will cross the existing
roadways and flow to the area disturbed during construction. It is recommended that the
proposed clean water diversions along the roadways be replaced with silt fences. This is
expected to minimize the disturbed area.
(Rev. I) Comment has been addressed
2. Sized for the smaller disturbed area, the proposed rain garden on the south side of the
property could be installed as a sediment trap. Please provide design, details, and
calculations for the proposed trap.
(Rev. I) Comment has been addressed
3. To direct any sediment -laden flow away from the reservoir and to the trap, a diversion
could be constructed from the area of the northeast rain garden to the sediment trap.
(Rev. I) Comment has been addressed
C. SWM Plan Review Comments
1. Please utilize the 4' contours from the County GIS maps as the existing topography. This
should allow you to show actual grading and dimensions of the proposed rain gardens.
(Rev. I) Comment has been addressed
The Erosion & Sediment Control and Stormwater Management Plans submitted 2 October
2008 have received Engineering Review and meet Albemarle County minimum checklist
items for approval. Please submit 5 paper copies of the Plan to Current Development
Engineering.
The E &SC bond amount is $5,700. The SWM bond amount is $5,110. The SWM
bond includes the plantings required for the disturbance of the reservoir buffer.
Mitigation is required at 2 times the disturbed acreage (0.05 x 2 = 0.1Oac) and the
following options are available (from the Albemarle County Design Standards Manual):
a. For every 400 square foot unit or fraction thereof, plant one (1) canopy tree measuring 1
1/2" — 2" caliper or a large evergreen 6 feet in height, one (1)
understory tree measuring 3 /a" — 1 1/2" caliper or one evergreen 4 feet in height, and one (1)
small shrub 15" —18" in height.
0.1Oac x 43,560sf /ac = 4356sf
4356sf x (1 canopy tree + I understory tree + 1 shrub) 1400sf = 11 of each plant (canopy
tree, understory tree, shrub) would be required for a total of 33 plants.
b. For every acre or fraction thereof, plant 1,210 hardwood and/or pine seedlings on
approximately 6'X6' centers without tree tubes and mats.
0.IOac x 1210 = 121 seedlings without tubes & mats
c. For every acre or fraction thereof, plant 600 hardwood and/or pine seedlings on
approximately 8'X8' centers with tree tubes and mats.
0.IOac x 600 = 60 seedlings with tubes & mats
These plantings can be anywhere within the buffer, however, Bob Crickenberger from
Albemarle County Parks & Recreation has suggested that the plantings be placed in a
location that will screen the new building from the existing roads. It is not necessary to
submit a new plan showing the location of the plantings.
Please contact Pam Shifflett (Albemarle County Department of Community Development)
at ext. 3246 for bonding procedures.
Once the E &SC bond and the SWM bond have been posted, you may contact the
Department of Community Development to arrange a pre - construction meeting. In
addition, should the County Inspector find the limits of disturbance increased or the need
for additional control measures required to protect the site, additional fees will be
required.
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