The Stillwater River Watershed TMDL
Background
The Stillwater River flows 67 miles from its headwaters in Indiana and northern Darke County to a confluence with the Great Miami River in Dayton. Major tributaries include Greenville Creek, Ludlow Creek, Painter Creek, Swamp Creek and North Fork Stillwater River. The watershed covers approximately 673 square miles (about 32 square miles in Indiana) and is drained by 280 miles of streams. Many of those stream miles have been physically modified to maintain drainage for row crop agriculture. Historically, almost one-third of the watershed may have been wetlands, but tile drainage and stream channelization have reduced this to one-half of one percent. Agriculture composes over 80 percent of the landuse, and Darke County has the second highest concentration of animal feeding operations (AFOs) in Ohio.
The TMDL Report
Ohio EPA has completed two TMDL reports based on monitoring completed in 1999.
- 2004 report
- 2009 report
- USEPA approved on September 8, 2009
- Recalculates the phosphorus loads at a more refined scale
- 2009 TMDL Report [PDF 5,248K]
Many of the documents referenced in the TMDL report can be found under Forms and Publications on the Ohio EPA Division of Surface Water Web page.
Supplemental Information
The two maps below illustrate the differences in the results of the 2004 and 2009 TMDLs. In the two maps, "needed percent reduction" is the percent decrease in the amount of the existing total phosphorus load needed to meet water quality goals. A greater needed percent reduction means that the stream is further from the goal. Refer to Table 4.10 in the 2009 TMDL report for more detail.
Needed Percent Reduction in Total Phosphorus Load for Meeting Water Quality Goals
For more information contact:
Dale White
Ohio Environmental Protection Agency
Division of Surface Water
P.O. Box 1049
Columbus, Ohio 43216-1049
dale.white@epa.state.oh.us