Water Quality Monitoring Program



Water quality is at the heart of what MSD does every day.




Visit our interactive Water Quality Story Map  to learn more about MSD's water quality program.





MSD monitors water quality and aquatic habit in the Mill Creek, Little Miami River, and Muddy Creek.


MSD partners with the Midwest Biodiversity Institute (MBI) to perform comprehensive biological, chemical, and physical sampling and analysis. The third round of water quality sampling began in summer 2021 and will continue through 2023.



The second round of sampling was conducted in 2016-2019:


The benchmarking (baseline) round of sampling was conducted in 2011-2014:



The Mill Creek Alliance, a local non-profit organization dedicated to restoring the Mill Creek, also conducts water quality monitoring in the Mill Creek. Visit their website for more information.

Photo of the Little Miami River at Otto Armleder Park
Lower Little Miami River at Otto Armleder Park




On November 8, 2023, MSD hosted a public forum on water quality in the lower Little Miami River.


The forum covered the results of a 2022 biological and water quality study (bioassessment) of the lower Little Miami commissioned by MSD and performed by the Midwest Biodiversity Institute (MBI).


The results show that 90% of the lower Little Miami mainstem is maintaining exceptional warmwater habitat for aquatic life use.


The study also shows widespread impairment of E. coli throughout the mainstem and tributaries. Sources of E. coli include combined sewer overflows (CSOs), home sewage treatment systems, and animal waste.


View the 2023 Little Miami River Presentation

View the 2023 Water Quality Forum Meeting (2 hours)



Bruce Koehler holding a striped bass caught in the Mill Creek
Commodore Bruce Koehler of the Mill Creek Yacht Club holding a striped bass caught in the Mill Creek.

Our Local Streams


The Recovering Mill Creek

The Mill Creek, once named the most endangered urban stream in America, is on its way toward recovery.

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Ohio Water Quality Standards

Water quality is impacted by many different sources and types of pollution.

learn more

Mitigating Low-Head Dams

MSD and other partners are helping mitigate low-head dams on the Mill Creek mainstem.

learn more