River Water Bacteria Levels

These sensors operate May 1 – October 31 and are dormant during the winter months (November 1 – April 30).

This map is here to help protect public health and safety by letting you know when it’s safer to be in the river. Rain can affect river conditions in two important ways:

• It can raise water levels and currents, making recreation unsafe.
• It can also wash bacteria into the river from sources like pet waste, storm sewers, septic tanks, and farm fields.

High bacteria levels can make people sick if river water is swallowed.

Using research from the Miami Conservancy District, this tool estimates E. coli bacteria concentrations—an indicator of fecal pollution—under different weather conditions. The Ohio EPA defines water as unsafe for recreation when E. coli exceeds 298 colony counts per 100 mL.

Condition Guide:

• Good Condition: Estimated low bacteria levels
• Advisory Condition: Estimated high bacteria levels
• Off Line: Sensor is not reporting data