The lower lake dam was constructed in 1949 and is the location of the intake tower for the treatment plant and public water supply. Drought conditions in the late 1970s led to re-evaluation of the lake supply and the city constructed a pump intake in the Missouri River to provide additional water. This pumping process is initiated when the lower lake surface drops to three feet below normal pool. The water plant was constructed in 1987. The treatment process is operated on a 2.0 Mgd flow rate for approximately 11 hours per day, producing an average daily output of 900,000 gallons.
Water is injected with chlorine dioxide to destroy bacteria and algae.
The lime is used for stabilization and further clarification. Fluoridation is added for dental health. Water flows by gravity from the secondary settling basin through filter beds of anthracite and sand. The plant has four filter beds through which the flow is split. The lake is treated with copper sulfate as needed, three to five times per year, to reduce taste and odor problems created by algae.