Smithville Lake Water Quality
Clay County samples water quality at all designated swimming beaches at Smithville Lake on a biweekly basis during the recreational season. The Missouri Department of Natural Resources has designated Smithville Lake as a body of water (lake) with recreational use category Whole Body Contact, category A (WBC-A).
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.
|Sample Collection Date||Little Platte Beach Left||Little Platte Beach Right||Little Platte Beach GeoMean||Camp Branch Beach|
|Camp Branch Beach|
|Cramp Branch Beach|
May 04, 2023
May 18, 2023
May 24, 2023
May 31, 2023
June 15, 2023
|June 29, 2023||3||1||2||5||36||13|
|July 12, 2023||25||10||16||30||57||41|
|July 26, 2023||62||96||77||13||113||38|
|August 9, 2023||31||24||27||44||96||65|
|August 23, 2023||96||66||80||260||50||114|
Water sample results can help visitors decide whether a particular beach is suitable for swimming, based on the bacteria levels. For waters designated as WBC-A, the state water quality standard is 126 E Coli colonies per 100mL of water during the recreational season (May 1 to September 1). Because of temporary fluctuations, MDNR uses a single event threshold of 190 colonies/100mL of water for E Coli concentrations. Clay County 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).