20071557 Ver 1_Restoration Plan Review_20071024

NC Division of Water Quality
401 Oversight and Express Permitting Unit
Memorandum
To: Ian McMillan
Kevin Barnett
File
From: Eric Kulz
October 24, 2007
Subject: DWO # 20071557
Comments on Stream and Wetland Restoration Plan -Rock Bridge Site/Hemphill
Creek (Haywood County)
Ian/Kevin:
They are proposing to "restore" 100 LF of Hemphill Creek, apparently in response to a NOV. It is
unclear to me what the impact to the creek was, and whether it actually needs restoring or not.
That should be Kevin's call.
The plan is kind of weak on details. A number of things on the design parameters table are odd.
Why are they reducing the width of the floodprone area from 306 feet (average) to 200 feet? How
are they going to do this?
Bankfull discharge is a constant, and is a product of the watershed size and runoff characteristics.
However, the table reports that the existing bankfull discharge is 726 cfs, and the design bankfull
discharge is 425 cfs..
The scariest thing is the sinuosity. The existing sinuosity is 1.04. The design sinuosity is 0.87.
This breaks several laws of physics.
North Carolina Division of Water Quality; 401 Oversight and Express Permitting Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://ncwaterquality.org/wetlands