Lake of the Ozarks water quality 2022

9 Things You Need To Know About Water Quality at Lake of the Ozarks:

1. Lake of the Ozarks has consistently tested as one of the cleanest lakes in Missouri.
2. Health Magazine recently proclaimed Lake of the Ozarks as one of the healthiest lakes in the country.
3. Only one of the hundreds of strains of E. coli causes serious illness. The primary risk of contracting one of those strains is through undercooked meat and raw vegetables.
4. Heavy rainfall in all bodies of water will temporarily influence water quality.
5. In the past three years, there have been no confirmed cases of sickness from the E coli bacteria due to swimming in the Lake of the Ozarks.
6. The natural flow of water at the Lake has a cleansing effect. Enough water flows into the Lake of the Ozarks each year to fill the Lake three times over.
7. Testing at Lake of the Ozarks is proactive and designed to help us gain an overall picture of the Lake’s water quality.
8. As would be true with any lake or river, swimmers should avoid drinking the water and take other normal precautions, such as washing their hands before handling food. With that in mind, it is safe to swim, ski and enjoy the water at
   the Lake of the Ozarks!
9. The Lake of the Ozarks is healthy and safe. We are taking proactive steps to insure the future environmental health of the Lake of the Ozarks continues. Please join us in our efforts.

Information provided by Citizens for the Preservation of Lake of the Ozarks.

“During the past several years, the Lake of the Ozarks has been the single most tested body of water in the State of Missouri. A total of 285 water samples were taken in 2011 and delivered to the Missouri Department of Natural Resources Water Testing Department.  According to the Missouri Department of Natural Resources Water Testing Department, the geometric mean (average over a period of time) for the 285 samples taken in 2011 was 3.0 compared to an acceptable level of 126.  The test results issued by the Department of Natural Resources for 2011 indicates that the Lake of the Ozarks is one of, if not the cleanest, body of water in the State of Missouri in terms of E. Coli bacteria.”

2007: 289 Total Samples - 4.9 Geometric Mean
2008: 324 Total Samples - 7.0 Geometric Mean
2009: 332 Total Samples - 8.8 Geometric Mean
2010: 312 Total Samples - 3.8 Geometric Mean
2011: 285 Total Samples - 3.0 Geometric Mean

LAKE OF THE OZARKS, Mo. (KY3) - Missouri Department of Natural Resources reminds everyone to check the DNR website before finding out if there is an advisory.

The Missouri Department of Natural Resources monitors two beaches at the Lake of the Ozarks. One at Grand Glaize Marina is considered safe to swim, but one near Brumley has an advisory. It means more bacteria in the water than there should be.

”We collect water samples weekly. They are taken to a laboratory in Jefferson City to be analyzed for E. coli concentrations,” said Coy King with the Missouri Department of Natural Resouces.

Typically there should be less than 190 E-Coli Concentrations. If the tests show more, then an advisory is put out.

What happens if you choose to swim during an advisory?

”If people swim when you exceed the 190, there is a potential for some health risk to occur to that individual,” said King.

Those health risks could be stomach aches, diarrhea, or even a low-grade fever.

Best way to be prepared? Check the DNR Website.

To report a correction or typo, please email

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Water Quality and Sampling 

The Missouri Department of Natural Resources samples water quality at all designated swimming beaches in the state park system on a weekly basis during the recreational season. The samples are analyzed at the Environmental Services Program laboratory in Jefferson City, and results are posted online. 

Water samples are analyzed for E. coli, a common indicator species for bacteria. It is normal for E. coli and other bacteria to be found at naturally-occurring levels in ponds, streams, rivers, lakes and reservoirs. Elevated bacteria levels are frequently associated with heavy rains; however, there are a number of other sources that may contribute to elevated bacteria levels, which may pose a health risk. 

Water sample results can help visitors decide whether a particular beach is suitable for swimming, based on the bacteria levels. In accordance with state law, Missouri Revised Statues section 640.080, RSMo, the Missouri Department of Natural Resources will post signs notifying visitors that swimming is not recommended if the geometric mean of the weekly water quality sample results exceeds the equivalent of 190 E. coli colonies per 100 milliliters of water (190 mpn/100 ml). 

Swim Healthy, Stay Healthy

Natural, uncontrolled bodies of water such as streams, lakes and ponds, all have naturally occurring bacteria at certain levels and some may contain pollutants. However, the Missouri Department of Health and Senior Services (DHSS) indicates that if you practice healthy swimming habits, you can enjoy natural bodies of water and reduce the potential for becoming ill. Learn more about tips to swim healthy, stay healthy by reviewing the DHSS Reducing the Risk of Waterborne Illnesses When Swimming in Natural Bodies of Water brochure.

Missouri State Park Beach Status 

Click on the name of the state park beach you’re interested in for beach status information and water quality data for that beach. Please note that the sample results provide a snapshot of the water quality at a specific time; however, they may not provide accurate representation of the water quality throughout the entire body of water. 

What is the water quality at Lake of the Ozarks?

Is it OK to swim in the Lake of the Ozarks?

Where is the cleanest water at Lake of the Ozarks?

Does the Lake of the Ozarks have E. coli?