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sampled by the Utah Division of Wildlife Resources (UDWR). We measured 10 channel cross- sections at 5 different times, using a tagline, r~rording depth sounder, and laser theodolite. Bathymetry was measured by holding boat position beneath the tagline at fixed locations. Cross-sections were replicated on November 3, 1992, June 10 and 22, August 15, and November 20, 1993 (Figs. 5,6). RESULTS These data were analyzed in the topography-generating subroutine of the Nelson and Smith's flow and transport model (1989). These computer-generated bed topographies were compared to show differences that were caused by passage of the 1993 flood (Fig. 7a) and the subsequent adjustment of the bar and thalweg from the summer low flow regime (Fig. 7c.) At the time of the first measurements (20 days after peak) during flood recession, the study reach was organized into two thalweg/bar sections and one cross-over section. Recessionary stages generally eroded to the margins of previously aggraded bars and filled the deepest parts of the thalweg. These surveys were compared to previous surveys of these cross sections conducted in 1986, 1987, and 1990 (Fig. 6) (Andrews and Nelson (1989), J. Lyons and G. Smith (written comm.)) Measurements during base flow during the past years show that the highest flood peaks deeply scour the thalweg, but do not necessarily build the highest bar tops. Flow and transport modeling will be necessary to evaluate the apparent discrepancies between peak flood stage and average elevation of bar surfaces. UDWR conducts physical and biological sampling of Colorado squawfish nursery habitat three times per year in the Ouray area. The low velocity nursery habitat for the endangered squawfish occurs in many geomorphic settings. Typical settings are A) the head of bars adjacent to the bank, B) remnant secondary channels at the downstream end of bars, C) areas eroded by horseshoe vortices found at the head of vegetated islands, D) the downstream end of mid-channel bars and E) low velocity areas created by stranded dunes on bar margins (Figs. 9, 10). The location ofUDWR sample areas were marked on prints from US Bureau of Reclamation (USBR) video overflights. We subsequently transferred these traces to a base map (Fig. 9), and the area of habitat sampled calculated. Data were analyzed for three dates prior to the 1993 flood, and two dates after flood recession. Our analysis of backwater sampling data shows that deeper backwaters have higher nutrient concentrations, more abundant macroinvertebrate populations, and higher squawfish densities. Generally deep backwaters are those exceeding .5 meters depth and these were considered "high quality" habitat. CONCLUSIONS * Peak discharge in 1993 was sufficient to scour the thalweg and aggrade the bars to elevations not measured in 7 years. * While overall area of available nursery habitat was significantly reduced by the 1993 flood, the amount of high quality nursery habitat changed less.