Total Maximum Daily Load (TMDL) Program 

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

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 waterbodies.  TMDLs are prepared for waters identified as impaired on the 303(d) list in the Integrated Report.

A TMDL is a written, quantitative assessment of water quality problems in a waterbody 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 waterbody.

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.

Map of TMDL project progress as of May 2013.

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.

Ottawa River (Toledo area)