2021 State of the Great Miami River Watershed

The figure below illustrates the water quality rating of the annual data for each sampling site. Click on a site to open a pdf detailing the annual data for that site's watershed.

Click here to open a pdf detailing the precipitation, minimum and maximum daily temperatures and the flow (cfs) of the Great Miami River at Hamilton for the week preceeding each monitoring day. (Viewing hint: a second tab will open when you click on a site. If you drag the tab to become its own window, each subsequent click will open in the second window allowing you to view the map and data simultaneously.)

Summary of 2021 Data by Dr. Michael Miller

In 2021 we had a high rainfall 52.6”, and high runoff (> 20,000 cfs) 5 times before July's monitoring date, then little.

TP was high at 0.3 mg P/l, and Nitrate-N comparably at almost 3 mg N/l. Tributaries were not the source of N and P, but upstream sources.

Conductivity was very high at nearly 700uS, the upper limit for the OEPA standard for warm water habitat.

E. coli geomean was 278 cfu/100ml for GMR and 23 cfu/100ml for the tributaries, with highest counts in March and November when significant rain events occured within 48 hours of sampling.