Effect of Bear River Storage on Water Quality in Bear Lake, Utah-Idaho

Robert L. Nunan, Utah State University


Since 1912 concentrations of the major anions and cations (except calcium) in Bear Lake water have shown a steady decrease which has been attributed to a dilution of Bear Lake by Bear River water, Bear Lake having been used as a reservoir for Bear River water since 1918. This study examined the changes which have occurred in Bear Lake water chemistry since 1912 and tested the validity of the dilution theory. Simple water and salinity budgets were determined for the Bear Lake system and used to simulate the effect of Bear River storage patterns since 1918 on the concentrations of sodium, potassium, magnesium, chloride, and sulfate in Bear Lake. Comparison of predicted concentrations with observed concentrations indicates that the dilution theory is a valid one. Field studies were conducted during the spring, summer, and fall of 1971 to describe the distribution of the major ions in Bear Lake with respect to space and time. No significant differences were found between samples collected.