Watkins Mill State Park and Lake of the Ozarks State Park’s Grand Glaize swimming beaches are closed due to water quality issues according to the Missouri Department of Natural Resources.

Results received today showed continued water quality issues at Watkins Mill State Park beach,” the department said in a press release. “Staff at Lake of the Ozarks State Park closed Grand Glaize Beach today when results showed that one of the two water samples taken at the beach failed to meet Missouri State Parks standards. Both beaches are scheduled to close for the recreational season after the Labor Day holiday weekend. Therefore, no additional water samples will be collected from the beaches and they will remain closed for the season. Public Beach #1 at Lake of the Ozarks State Park remains open until Sept. 4.”

The water at all designated beaches in the state park system is sampled weekly during the recreational season by the Missouri Department of Natural Resources to determine suitability for swimming. Water quality can be determined to be unsuitable for swimming based on either the single sample taken earlier in the week, or by the geometric mean, which is a mathematical value that takes into consideration results from the current week plus the results taken during the previous weeks. Both beaches closed this week had single samples in excess of the standard. The beach at Watkins Mill State Park also exceeds the geometric mean, which is a mathematical value that takes into consideration results from the current week plus the results taken during the previous weeks.

Higher bacteria levels are often associated with heavy rains that result in runoff from adjacent lands. However, there are a number of possibilities that can contribute to higher bacteria, and chances are no single source is the cause. The sample test results indicate a snap shot of the water quality taken at the beaches at a specific time; however, a single sample does not provide an overall sense of the water quality in the lake where the beach is located.

The beaches at two parks, Lewis and Clark State Park in Buchanan County and Trail of Tears State Park, Cape Girardeau County, remain closed for maintenance unrelated to water quality. Visit mostateparks.com for additional information.