A reservoir that supplies water for the city of Lawrence is filling with sediment faster than planned, reducing the lake’s storage supply.

A two-year study by the U.S. Geological Survey in Lawrence says Clinton Lake is filling with sediment 70 percent faster than planners expected when the reservoir was finished in 1977. The study says, however, that equates to a filling rate of about one-quarter of a percent a year, which the USGS says isn’t unusually high.

The study was done with the Kansas Department of Health and Environment.

It also said Clinton Lake had had increased incidences of algae blooms, which can make the water taste bad. Large algae blooms can also create toxins.