Subject: Davidson River & Grogan Creek flow gauge assessment From: "Scott Loftis" Date: Fri, 24 Feb 2006 16:41:50 -0500 To: "'Murry, John'" , "'Ferguson, Jeff'" , "'Dodd, Brady'" , "'Amentt, Melissa'" , "'Tarver, Fred'" , "'Stroup, Lorie'" CC: "'Borawa, Jim'" , "'Kittel, Carl'" All, Thanks for everyone's time and input during our initial site assessment for flow gauge construction on Davidson River and Grogan Creek. Based on our discussions, it was decided that a staff gauge would be more practical than constructing a "V" notch gauge at either site. Several locations for staff gauge placement were considered at each site. It was determined that the best location for the staff gauge on the Davidson River would be just upstream of the intake on the inside portion of the point bar. Placement of the gauge will be similar on Grogan Creek, just upstream of the intake, but easily accessible/readable by Commission staff. Placement of gauges on the weirs had inherent problems, particularly because the weirs are downstream from the intake structures. The intakes presented other problems for gauge placement; such as, hydraulics, especially during low flows and maximum withdrawal. Davidson River presented more of a hurdle than Grogan Creek. The most obvious is the proposed channel modification work, which will affect water levels. Second, the crest plate on the weir has been compromised and will need to be fixed or replaced to maintain a constant water elevation in the forebay. These activities will need to be completed before gauge placement and calibration occurs. Also, there is a question about the trout buffer variance requirement on the Davidson River. Work within the buffer extending for more than 100 linear feet requires a variance from the Division of Land Resources. However, we pulled a tape to get an idea of channel modification length and it was right at 100 linear feet. I feel that we will be able to proceed with the modification without going through the trout buffer variance request, fortunately. Thus, we should plan to proceed with the modification work starting sometime in May or the early summer. Grogan Creek presented less of a challenge. Therefore, it was decided to do it first. The plan is to acquire the necessary gauge equipment/materials and perform the placement of this gauge the last week of April (week of April 24th) and begin calibration shortly thereafter. If I have failed to capture some pertinent aspect of our discussions, please email your comments to the group. I will contact folks in April to confirm the dates for gauge placement on Grogan Creek. Thanks! Scott Loftis NCWRC - Watershed Enhancement Coord. Old Fish Hatchery 20830 Great Smoky Mtn. Exp. Waynesville, NC 28786 (828) 452-6191 ext. 26 office (828) 506-8950 mobile (828) 452-7772 fax