Reclamation Information Sharing Environment (RISE)

Reclamation and the State of Montana studied the reasons for increasing turbidity in Clark Canyon Reservoir, Montana. Reclamation personnel collected data and developed and used the CE-QUAL W2 model. Reservoir elevations combined with wind events resulted in increases in down stream turbidity during times reservoir elevations and temperature conditions allowed mixing and the development of a single large circulation cell. Changing potential release elevations were studied at the request of some user groups, and CE-QUAL is one way to simulate operational scenarios. Changing release levels may impact downstream turbidity with shallower releases initially resulting in lower downstream turbidity until reservoir turnover occurs. Included with the report are two supplemental reports which are also attached as appendices to the final report. These reports detail analysis of Acoustic Doppler (ADCP) data, and the results of the CE-QUAL modelling study. Water quality profile datasets are also included for years 2017 and 2018, and include daily profile data for Dissolved Oxygen, Specific Conductance, Temperature, Turbidity and pH. These datasets were used during model development and in describing in reservoir conditions.