HomeMy WebLinkAboutSDP201100033 Legacy Document 2011-07-06 (6)�P+ ots
Dominion
m y Engineering 172 South Pantops Drive
ii Charlottesville, VA 22911
a LL 434.979.8121 (p)
4��0 r 434.979.1681 (f)
ects DominionEng.com
May 16, 2011
Revised June 20, 2011
Mr. Glenn Brooks, P.E.
County EnginTeer
Albemarle County Community Development
401 McIntire Road
Charlottesville, VA 22903
RE. Dunlora Forest Subdivision — TM 62F -A, TM 62 -166 and TM 62D-IA, Albemarle County,
Virginia - Critical Slopes Waiver Request
Dear Glenn,
This letter and attached preliminary site plan and application fee shall serve to request a waiver of Z.O.
Section 4.2 to allow the disturbance of critical slopes. This request is being made in accordance with Z.O.
Section 4.2.5. The site is located at the northeast intersection of Rio Road and Pen Park Drive and
consists of approximately 22.3 acres of land. The developer is proposing to construct 93 residential units
(58 duplexes and 35 townhouses), including the necessary roadway and utilities to support the proposed
development. Also proposed are a tennis court, tot lot and a nature trail that is to meander through the
rear of the site.
The site generally slopes from Rio Road to the east where runoff flows via sheet flow, shallow
concentrated flow and ditch flow to an existing stream.
There are approximately 6.09 acres of critical slopes located onsite as shown on the Preliminary Site Plan.
Of these, the developer proposes to disturb approximately 2.95 acres of the critical slopes. However, the
majority of the critical slopes that are being disturbed are located well landward of the stream. The main
concentration of critical slopes are located along the northeastern edge of the property. These critical
slopes are to remain largely undisturbed as they are located adjacent to the existing stream. The only
disturbance proposed to these slopes are clearing from a proposed sanitary sewer main and incidental
grading at the top of the slope to provide adequate drainage at the rear of the proposed duplexes. There
are other areas of existing critical slopes onsite that are to be disturbed which are located significantly
landward of the stream and no negative impacts are anticipated from their disturbance.
The developer will also address the following concerns:
Rapid and/or large scale movement of soil and rock
Prior to commencement of land - disturbing activities, the developer will obtain County approval of an
erosion and sediment control plan prepared in accordance with the minimum standards of the Virginia
Erosion and Sediment Control Handbook. These plans shall address protection of the slopes,by the use of
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c°ji °tea Dominion
m y Engineering 172 South Pantops Drive
Charlottesville, VA 22911
434.979.8121 (p)
4��eh 434.979.1681 (f)
e °ts DominionEng.com
silt fence, diversions or other measures that will direct excessive runoff from flowing over the slope,
thereby reducing the possibility of the rapid and/or large scale movement of soil and rock. In fact,
following development, there will be less runoff flowing over the slope since the majority of the upstream
area will be collected in storm sewer pipe and ditches and be re- directed to the proposed stormwater
management facility at the southeast corner of the site.
Excessive stormwater runoff
Prior to commencement of land - disturbing activities, the developer will also obtain County approval of a
Stormwater Management Plan that will provide calculations indicating that post - development runoff
levels into the receiving stream will not increase over pre - development levels. It is anticipated that in
order to address the concern of excessive stormwater runoff, the developer will construct a wet
stormwater management pond facility at the southeastern corner of the site and utilize other techniques
such as water.quality swales to increase the time of concentration closer to pre - development levels. Also
note that the runoff over the critical slopes to remain will be analyzed to indicate a net reduction in runoff
over the slopes following development. This will be accomplished by diverting runoff around theses
slopes.
Siltation of natural and man -made bodies of water
Prior to commencement of land- disturbing activities, the developer will obtain County approval of an
erosion and sediment control plan prepared in accordance with the Virginia Erosion and Sediment Control
Handbook. This plan will indicate sediment trapping measures such as silt fence, diversion dikes,
sediment traps, check dams and outlet protection that will serve to adequately protect the receiving stream
from Siltation.
Loss of aesthetic resources
There will be no net loss of aesthetic resources. Consistent with approval of a landscape /conservation
plan for the site, the developer will be exceeding the minimum tree canopy cover requirement for the site.
Also, the plan shall indicate how the trees and vegetation on the existing critical slopes will be protected
throughout construction, thereby protecting the natural appearance of the stream corridor. The proposed
wet pond is also located significantly upstream from the stream bank to maintain the aesthetics of the
stream corridor at the southeast corner of the site.
The item with respect to septic system failure does not apply to this request since the site is on
public water and sewer.
I thank you for taking the time to review this request and we look forward to your favorable response.
Sincerel ,
Michael F. e , E.
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