20160095 Ver 1_Stormwater Info Response_20160906

Strickland, Bev
From: Robert Davis <[e-mail]>
Sent: Tuesday, September 06, 2016 11:24 AM
To: Larsen, Cory
Subject: The Woods Stormwater plan
Follow Up Flag: Follow up
Flag Status: Flagged
Cory
After our talk on Friday we addressed the issues in you email. We also did the following:
1. We added a check dam detail that has filter fabric and washed stone on the upstream
side. While the standard shown is to initially stabilize the outlet swale with grass, we believe
that the check dam will hold silt and sediment and will transition into a linear wetland.
2. We agree that the discharge at the outlet on lot 56 is too high. That big swale also hurts the
marketability of the lot. We split the flow and created anther outlet between lots 52and
53. This spreads the impact, more closely follows the natural drainage patterns, and is a much
smaller impact on the lots.
3. We revised ditch 4A to a stream restoration with a meandering path that lowers the slope,
reduces velocity, and creates a more natural visual appearance. In our experience, this kind of
design will often develop naturally into jurisdictional linear wetland or intermittent stream.
4. We revised the deed restriction standards to include a requirement of point source water
quality treatment by a variety of means at section 4.1.5. This creates an environment that site
specific alternatives can be employed to best treat and maintain runoff in a manor most
advantageous to the unique site characteristics and the homeowners' preference.
5. We did not revise the Stormwater discharge analysis since all of the alternatives besides the
disconnected standard involve the capture of the first 1" rainfall for a extended period of time
with will lead to significantly less peak runoff from the homesites that employ those methods.
I wish to thank you again for your comments and input. I truly believe that the result is a significantly
better project for the future residents and the environment.
Please see the dropbox link below for the final plans
Bob Davis, PE
https://www.dropbox.com/sh/ncgrn3y4yal t6wg/AABLgHfGwsGYhDUEaglZhhQAa?dl=O