The Great Miami River (upper) Watershed TMDL
The Great Miami River (upper) Watershed Total Maximum Daily Load (TMDL) report was approved by U.S. EPA on March 26, 2012. TMDL reports identify and evaluate water quality problems in impaired water bodies and propose solutions to bring those waters into attainment with water quality standards.
The Great Miami River (upper) watershed is located in western Ohio in Logan, Shelby, Mercer, Auglaize, Darke, Champaign, Hardin and Miami counties and drains 748 square miles. The river flows into the Ohio River west of Cincinnati. The upper portion of the watershed covers approximately one-third of the drainage area of the Great Miami River basin and is home to two lakes used heavily for recreation (Indian Lake and Lake Loramie). Bellefontaine, Sidney and Minster are the three largest communities in the watershed. Land use in the Great Miami River (upper) watershed is comprised of 71% cultivated crops, 8% pasture and hay, 9% forest and 9% developed land.
Ohio EPA conducted water quality monitoring in 2008. The Great Miami River and some of its tributaries displayed good quality, while tributaries in the western portions of the watershed were generally of a lower quality. Aquatic life uses were supported at 64% of sites; 26% of sites partially attained and 10% did not attain. The three most common causes of aquatic life use impairment include habitat alterations, nutrients and sedimentation. Probable sources include channelization, agricultural land uses and point sources. About 72% of the sites failed to meet bacteria water quality standards. Probable sources of bacteria include failing septic systems and agricultural land uses.
TMDLs were calculated for total phosphorus, habitat, sediment, total dissolved solids and E. coli bacteria. Recommendations include new effluent limits for total phosphorus and total dissolved solids, reducing overland flow and nutrient inputs, improving riparian vegetation and stabilizing stream banks, identifying and fixing failing home sewage treatment systems and using proper land application of manure and biosolids.
The TMDL Report
Many of the documents referenced in the TMDL report can be found on the Forms and Publications page.
Supplemental Information
The following documents provide background information on the Great Miami River (upper) watershed. Ohio EPA is not requesting comments on these documents.
- Fact sheet [PDF 497K]
- Biological and Water Quality Study of the Upper Great Miami River and Selected Tributaries, 2008. Auglaize, Mercer, Logan, Shelby, Champaign, and Darke Counties.
For more information contact:
Beth Risley
Ohio Environmental Protection Agency
Division of Surface Water
P.O. Box 1049
Columbus, Ohio 43216
beth.risley@epa.state.oh.us