Principal Watersheds



These are water quality monitoring sites that the Central District Office field staff have been monitoring for many years as part of the National Ambient Water Quality Monitoring Network (NAWQM).


Location Name

Storet I.D.

Olentangy River at Worthington


Mill Creek at Marysville downstream of McArthur Park


Licking River at Stadden’s Bridge Road


Mohican River at Greer, state Route 514


Kokosing River at Tilden Avenue


Hocking River downstream of Lancaster at Wilson’s Road


Scioto River at Florence Chapel Road


Big Darby Creek at Darbyville, state Route 316


Paint Creek near Greenfield, state Route 753




National Pollutant Discharge Elimination System Tools

A National Pollutant Discharge Elimination System (NPDES) permit is required to discharge to waters of the State of Ohio. There are two types of NPDES permits: individual permits for a specific facility; or general permits that are issued to a class of facilities.

Individual NPDES Permits                       

General NPDES Permits

Available General Permits

The NOI and the following listed permits are those most likely to be used in the Central District Office. For a complete list of available general permits, please go to the Division of Surface Water (DSW) website.

For non-storm water permits, go to: Non-Storm Water Permits List 

For storm water permits, go to: Storm Water Permits

Other General NPDES Permits


Permit-to-Install Tools

A permit-to-install (PTI) is required for installation of disposal systems such as sanitary sewers, wastewater treatment works and commercial on-lot disposal systems with a flow of greater than 1,000 gallons per day.

Non-refundable fees include a $100 application fee plus a plan review fee of $100 plus 0.65 percent of the project cost (max $15,100). 

On-site Treatment Systems – A soil survey is required to complete the technical review for these systems. A soil survey may be obtained by contacting a soil scientist. For more information go to:

A permit to discharge storm water is required if you engage in land disturbing activity of greater than 1 acre, or if you are an industry identified by certain Standard Industrial Code (SIC) number, or if you are a municipality or other government entity operating a municipal separate storm sewer system (MS4).

Under any circumstance, you are required to prepare and follow a Storm Water Pollution Prevention Plan (SWP3).


Total Maximum Daily Load Reports (TMDLs) are a report that identifies loading reductions of pollutants necessary to achieve chemical water quality standards (WQS). The TMDL reports will also identify surrogate measures that may be used to assess the likelihood that impaired waters will be restored to a level of biological performance that will achieve WQS.

This page is focused on TMDL activity in Central District Office. For more information on the statewide TMDL program, go here:

For more information on Water Quality Standards, go here:

Completed TMDL Projects:

 TMDL Projects in Progress:

  • Walnut Creek   
  • Kokosing River    
  • Paint Creek 
  • Hocking River

Rural Drainage Advisory Committee Links: