HomeMy WebLinkAboutZMA201300013 Review Comments Critical Slope Waiver 2013-08-22*-&A
County of Albemarle
Department of Community Development
Memorandum
To: Claudette Grant, Current Development planning and zoning review
From: Michael Koslow, Current Development engineering review
Date: 22 August 2013
Subject: Keswick Lake (ZMA201300013) critical slope waiver request
The critical slope waiver request dated 6/24/2013 has been reviewed. The engineering analysis of the
request follows:
Description of critical slope area and proposed disturbance:
This is a proposed 22 lot subdivision and includes 45 critical slope areas in TMP 79 -36, 79 -23, and 79C -1.
The applicant is proposing to serve 22 development units and associated driveways with undefined
proposed slopes.
Areas A
Acres
Total site 9
95.37 acres approximately*
Critical slopes 1
19.05* 2
20% of site
Critical slopes disturbed 0
0 ** 0
0% of critical slopes
-includes TMP 79-36,79-23, and 79C -1
** - all critical slope disturbances proposed are exempt due to being for road, water, sewer, or
stormwater management infrastructure with no reasonable alternative locations
The area of disturbances to existing critical slopes is likely to change based on driveway alignment
changes and construction of stormwater management facilities required for subdivision of subject
parcels.
Exemptions to critical slopes waivers for driveways, roads and utilities without reasonable
alternative locations:
All disturbances proposed for land development (not home construction) appear to be exempt (see below).
Compliance with Zoning Ordinance 18 -4.2:
"movement of soil and rock"
Proper slope construction, control of drainage, and vegetative stabilization should prevent any
movement of soil. Much of that will depend on activities of individual home builders.
"excessive stormwater runoff'
Stormwater runoff will be increased in this area, as steeper man-made slopes typically result from
leveling associated with building construction.
"siltation"
Inspection and bonding by the County will help to ensure siltation control during construction. Proper
stabilization and maintenance can help long term stability. However, the houses proposed adjacent to
existing critical slopes areas (Lots 2 -7, 10, 11, 21, and 11) make future critical slope disturbances
likely.
Albemarle County Community Development
Engineering Review comments
Page 2 of 2
"loss of aesthetic resource"
The proposed rezoning does limit the proposed critical slope disturbances; however further
disturbances are likely (see above).
"septic effluent"
This neighborhood is proposed to be served by a Central System known as "The Living Machine."
The full build out of leads and outlet pipes for this system has not been shown on the rezoning plan
(ZMA2013- 00013)
Based on the review above, engineering recommends revision of critical slopes waiver request to address
the complete scope of disturbances which would be needed to serve the 22 proposed lots and protecting
areas of lots proposed where future critical slopes disturbances and stream buffer impacts are likely. An
overlot grading plan would ensure future critical slopes disturbances are minimized during home
construction.
file: C:A Users \mkoslow\ Documents \CUrrentReviews\ZMA201300013 Keswick LakeAEI csw MAK ZMA20 1 3 000 1 3 Keswick Lake.doc