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Introduction <br />• The Governance committee of the Platte River Program contracted with the Bureau of <br />Reclamation, Sedimentation and River Hydraulics Group at the Technical Service Center, <br />to do an analysis of three methods to compute a water surface elevation. The water <br />surface elevation is to be computed for the day a Whooping Crane was sited, using data <br />from a day when a survey crew returned to obtain a stadia transect survey at the <br />approximate Whooping Crane roost site. The study is divided into two phases and the <br />first phase is a pilot study to determine the most feasible means of computing the change <br />in water surface by considering 10 WC sites. If an analysis is recommended by the TAC <br />that requires additional on-site analysis, Reclamation wM comptete the analysis of thu <br />remaining 99 sites in phase II. <br />Three methods were considered in the phase I analysis: <br />Method 1. Apply the differential in water surface at the USGS gage to the Whooping <br />Crane sight. <br />Method 2. Use a Mannings equation (applied to transects surveyed at crane sighting) site <br />calculation, combined with a ratio (based on USGS Q on Crane day and after Crane day <br />sighting) to estimate water surface elevation. <br />Method 3. Use a HECRAS model and calibrate with Q ratio2. <br />• The Cooperative Agreement Executive Directors Office provided Cooperative <br />Agreement data for Whooping Crane sightings, and also provided decoy data that had <br />three surveys at each location where a WC decoy had been placed. The decoy data was <br />used instead of WC sites when it was available (no decoy data downstream of Grand <br />Island gage), since this data included additional transect and water surface information. <br />Two decoy sites in the Overton Reach, four decoy sites in the Kearney Reach, and four <br />WC sites from the Grand Island Reach were selected for the phase I comparison of <br />methods. A brief description of the analysis and results from the first phase of the study <br />are presented here. <br />Analysis Methods <br />The WC transect data is from a stadia survey of the channel where the Whooping Crane <br />was observed. The survey occurs after the crane has departed and is sited at the <br />approximate location of the roost. Three transects, an upstream, middle and downstream <br />transect, were measured perpendicular to flow. The transects traverse the channel where <br />the crane roosted but may not extend the full width of the flood plain. Each transect had <br />between 7 and 80 data points and the transect end points are reported as UTM values <br />providing horizontal control. The elevation data at each transect is relative to the height <br />2 Because the Platte River HECRAS model uses cross sections which provide estimates of the flows in <br />• multiple channels, and transects were inserted into the cross sections, it was not necessary to develop a <br />ratio. <br />Summary of Phase I Whooping Crane Data Analysis November 6, 2007 <br />2 <br />