HomeMy WebLinkAboutWPO200700045 Review Comments 2007-09-24YlAGIl`11A
County of Albemarle
Department of Communitv Develoument
Memorandum
To: Rio Holdings LLC [973- 9120], Eric Woolley [ericwoolley @thecoxcompany.biz]
From: Jonathan Sharp, Engineering review Usharp @albemarle.org, 296 -5832 ex 3025]
Date: 19 Sep 2007
Subject: Stonewater Subdivision: Engineering concerns
Before the Stonewater Subdivision plan can proceed forward in the review /approval process, there are
major Engineering concerns which need to be addressed prior to focusing on the minor comments /details
of the project. It appears that in order to address these issues, layout changes to the plans maybe required.
Engineering would like to work with you in tackling these issues adequately and in a timely manner.
There are two major concerns that need to be addressed: drainage and stormwater management.
Drainage issues:
1) The current proposed plan presents potential drainage problems for the lots, especially lots 1 -16. The
use of collecting runoff in a drop inlet is inadequate. There is no overland relief provided, as inlet clogging
or failure could result in flooding of proposed or existing structures. This is also why Engineering can not
approve a waiver of easement reduction for the stormwater pipe system serving lots 1 -16.
2) The use of the v -ditch to collect runoff from lots 1 -12 is also inadequate. As proposed, very little runoff
will collect in the ditch and drainage will continue to drain through over 3 lots. This can lead to
drainage /flooding problems in these lots.
3) The drainage situation has not taking into account grading /development of individual lots. You cannot
simply address drainage for the roadway, as the purpose of the road is to provide access to single family
homes on the lots. One possible solution is to provide an over lot grading plan.
Stormwater Management:
1) Stormwater detention is required. Engineering can not grant a detention waiver, as runoff drains through
an adjacent parcel before reaching the floodplain. Combining facilities with the adjacent parcel to outlet to
the floodplain does not provide grounds to grant a detention waiver.
2) Water quality must capture as much of the runoff of the development as possible. The current proposed
plan focuses on capturing the roadway, but not future development (houses /driveways /etc.). For example,
runoff from lots 1 -15 collects into a piping system, but the pipe system bypasses the stormwater facility.
Please provide a plan which captures and treats as much of the development as possible.
In short, we cannot treat this development to be simply a road plan; the development of homes in the lots
must be taken into account, as the purpose of the road is to serve the lots. I wanted to express these
concerns to you in writing so they are clear. Feel free to contact me or schedule a Thursday Engineering
meeting if you have any questions and to work out possible solutions.
Thanks,
Jon Sharp