The Phosphorus Budget of the Upper Little Bear River-Hyrum Reservoir Watershed

William A. Luce, Utah State University


Phosphorus concentrations in the water of the Hyrum reservoir - Little Bear River watershed were determined by collecting 12 samples every two weeks over a seven month period and analyzing them for dissolved orthophosphate, total dissolved phosphorus, and total unfiltered phosphorus. The concentrations obtained were used in conjunction with a water budget to determine a phosphorus budget. Apparent major inputs of phosphorus to the reservoir included a trout farm and runoff from agricultural land in the watershed. Statistical analyses of the data were made to determine what effect precipitation, streamflow, and mileage downstream had on the concentrations of phosphorus in the watershed.