20071134 Ver 2_Email_20080219

Re: R-2518B
Subject: Re: R-2518B
From: "W. G. (Galen) Cail" <[e-mail]>
Date: Tue, 19 Feb 2008 08:31:55 -0500
To: Brian Wrenn <[e-mail]>
CC: Jeff Hemphill <[e-mail]>
Brian.
We will provide a note on the plans to backfill extensions with natural bed
material. Also, I spoke with Jamie about outlet at Site 27. We will call for
Class I outlet protection at the 600. He said during construction they could
call to armor the pool if there looks to be a stability issue.
Do you need updated permit drawings for these sites?
Thanks
Galen
Brian Wrenn wrote:
Thanks Galen. As a precaution, I would like to see backfilling of pipe
with natural bed material for sites 3 and 12. Let me know what you find
out on Site 27.
Brian
W. G. (Galen) Cail wrote:
Morning Jeff and Brian. Took a look at these sites and offer the
following:
Site 3/ Site 12 -- We have not called for backfilling pipes or rock inlet
sills. And to be honest I don't remember these sites ..... been a while
since I've been out there. At both sites we are extending pipes at the
existing pipe slopes. Do you recall if there is headcutting presently or
the type of bed material? If there is no headcutting presently or the bed
is predominantly rock don't know if a rock inlet sill would be needed since
headcutting potential may be low. However, probably not a bad idea to
backfill pipes (w/ Class I or Natural Bed Material?).
Site 25 -- Good catch. The lateral ditch is flowing to the stream. Flow
patterns shown incorrectly. we will revise.
Site 27 -- No, presently we are not calling for any outlet protection for
the 600. Let me check with Jamie Lancaster. This is one of their
mitigation sites which includes rock vanes and pools. If their proposal
doesn't call for an armored pool at this location then we will revise
drainage to call for outlet protection.
Galen
Jeff Hemphill wrote:
Galen
Brian had some questions in regard to the 401 mod for R-2518B:
* Site 3/Sheet 5: Brian is concerned about headcuts on the upstream
end of the pipe - are we proposing to install bed material in the
pipe or some sort of energy dissipator? Can we put a crossvane
upstream to minimize headcutting?
* Site 12/Sheet 12: Same concern as Site 3
1 of 2 2/21/2008 10:12 AM
Re: R-2518B
* Site 25/Sheet 28: The lateral base ditch from Station 200.80 to
201.90 appears to flow away from stream
* Site 27/Sheet 30: Is there any outfall protection for the
stormwater pipe that ends at the headwall? Is there an Energy
dissipator at the outlet end of the proposed twin barrel CSP?
Brian praised your efforts on stormwater treatment for this section.
Jeff Hemphill
NEU
2 of 2 2/21/2008 10:12 AM