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Total Maximum Daily Load (TMDL) Program

The Total Maximum Daily Load (TMDL) program, established under Section 303(d) of the Clean Water Act, focuses on identifying and restoring polluted rivers, streams, lakes and other surface water bodies. TMDLs are prepared for waters identified as impaired on the 303(d) list in the Integrated Report.

Information about TMDLs and water quality monitoring are organized by large watershed. The watersheds are shown in the map to the right. Watershed names are linked to pages with further information. Ohio typically focuses on  watersheds in preparing TMDLs.

What is a watershed?

A watershed is the area of land that drains into a lake or stream. Watersheds can be small - like the area that drains into the creek behind your house. Or, watersheds can be large - consider all the land, streams and rivers that drain into the Ohio River or Lake Erie.

Multi-Watershed TMDLs

Click on the watershed labels to be taken to their respective pages.

Ottawa River (Toledo area)

What's New

Ohio's TMDL Process

A TMDL is a written, quantitative assessment of water quality problems in a water body and contributing sources of pollution. It specifies the amount a pollutant needs to be reduced to meet water quality standards (WQS), allocates pollutant load reductions, and provides the basis for taking actions needed to restore a water body. Read more about Ohio EPA's TMDL process.

Ohio developed a 12-step project-management-based TMDL process to accomplish TMDLs. The process builds on existing monitoring, modeling, permitting and grant programs in an attempt to establish a cycle of continuous improvement of the water quality in Ohio's watersheds.  The process, which seeks public involvement in problem-solving and decision-making, contains four broad, overlapping phases:

  • Assess waterbody health: biological, chemical, habitat
  • Develop a restoration target and a viable scenario
  • Implement the solution: inside/outside Ohio EPA
  • Validate to monitor progress: delist or relist.

To gain the perspective of interests outside Ohio EPA, an external advisory group of about 80 people met for over a year to discuss options and recommend how Ohio should approach TMDLs. Their recommendations to the director of Ohio EPA in June 2000 addressed the listing process, how TMDLs should be developed and implemented, and how Ohio should deal with special problems such as mercury and air deposition.

Additional information about TMDLs is available on the U.S. EPA TMDL website.


The individual watershed pages on the website contain information on TMDL implementation projects that have been funded through Ohio EPA's Nonpoint Source Pollution grants program.  The listed projects are not all inclusive.  For more information regarding projects funded through these grant programs, see the following links:

TMDL Project Contacts 

Kokosing River, Licking River, Paint Creek, Big Darby Creek, Big Walnut Creek, Bokes Creek, Deer Creek, Mill Creek, Olentangy River, Scioto River, Walnut Creek  
Zawiski, Bill
Ashtabula River, Chagrin River, Euclid Creek, Lake Erie tributaries, Beaver Creek, Black River, Rocky River, Cuyahoga River, Grand River, Mahoning River, Nimishillen Creek, Tuscarawas River, Killbuck Creek, Sandy Creek, Sugar Creek, Conneaut Creek, Pymatuning,  Yankee and Little Yankee creeks, Little Beaver Creek  (330) 963-1134
Barnswell, Kristopher  (NWDO) Huron River, Old Woman Creek, Vermilion River, Auglaize River, Blanchard River, Maumee River, Lake Erie tributaries, Ottawa River, Powell  Creek, St. Joseph River, St. Marys River, Swan Creek, Tiffin River, Mohican River, Portage River, Toussaint River, Sandusky River and tributaries, Beaver Creek, Mississinewa River, Wabash River  (419) 373-3023
Jackson, Joshua              (SWDO) Fourmile Creek, Great Miami River, Indian Creek, Mad River, Stillwater River, Twin Creek, East Fork Little Miami River, Little Miami River, Mill Creek,  Whitewater River, White Oak Creek (937) 285-6029
Taulbee, Rachel            (SEDO) Hocking River, Monday Creek, Sunday Creek, Conotton Creek, Moxahala Creek, Muskingum River, Salt Creek, Stillwater Creek, Wakatomika Creek, Walhonding River tributaries, Wills Creek, Captina Creek, McMahon Creek, Cross, Shore and Wheeling creeks, Duck Creek, Leading Creek, Ohio River tributaries, Ohio Brush Creek, Pine, Ice and Little Scioto creeks, Raccoon Creek, Symmes Creek, Scioto Brush Creek  (740) 380-5433