20080355 Ver 1_Staff Comments_20080228

Little Alamance Creek
Subject: Little Alamance Creek
From: Sue Homewood <[e-mail]>
Date: Thu, 28 Feb 2008 12:34:40 -0500
To: Eric Kulz <Eric. Kulz@ncmail. net>
08-0324
I have mostly the same comments regarding the stormwater BMPs. There are some locations on this
project that concern me that the slope down gradient of the level spreader may be too steep. The plans
are too small to be sure but it looks like a possibility. I also don't see the last level spreader shown on
the plans at station 35+00.
Also, is it appropriate for us to require an inspection/maintenance agreement for these BMPs as we
would for any other project building a BMP as part of it?
-------- Original Message --------
Subject:Brown Branch
Date:Thu, 28 Feb 2008 12:07:51 -0500
From:Sue Homewood <Sue.Homewood (a-,ncmail.net>
Organization:NC DENR - Winston-Salem Regional Office
To:Eric Kulz <Eric.Kulz(a,ncmail.net>
08-0355
Eric,
My semi-learned understanding of design of level spreaders leads me to believe that these may not be
designed properly.
They do not provide calculations to determine how they calculated the peak flow. But even if we
accept their numbers without calculations, they design the level spreader lengths as if there was going
to be dense ground cover in the buffer, but their planting design is for an alluvial forest and that is not
dense ground cover. So their level spreaders should be significantly longer (and in some cases may
not work).
If you believe we should be reviewing their stormwater plan in order to qualify this channel for
mitigation, then I suggest you run it by Annette, because my quick look indicates concerns. I believe
that the BMPs they are suggesting should meet our design standards to ensure that relocating the
stormwater pipes does not cause more harm to the buffer they are about to plant and get credit for.
Sue
Sue Homewood
NC DENR Winston-Salem Regional Office
Division of Water Quality
585 Waughtown Street
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