The Big Darby Creek Watershed TMDL
Background
The Big Darby Creek Total Maximum Daily Load (TMDL) report was approved by U.S. EPA on March 31, 2006. The report is the twenty-second Ohio TMDL project approved by U.S. EPA under Section 303(d) of the Clean Water Act. 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 Big Darby Creek watershed is located in central Ohio, draining agricultural areas and suburbs to the northwest and west of Columbus. The basin is primarily in Logan, Union, Champaign, Clark, Madison, Franklin, and Pickaway counties. Major streams included in the TMDL report are Big Darby Creek, Little Darby Creek, Hellbranch Run, and Flat Branch.
A comprehensive survey of the Big Darby Creek watershed was conducted by Ohio EPA in 2001-2002. The biological and water quality study was published in 2004 and is available under Supplemental Information below. The primary causes of impairment include nutrient enrichment, siltation, organic enrichment, pathogens, low dissolved oxygen, and habitat alterations. Pollution sources in the watershed include row crop agriculture and pastures, home sewage treatment systems, development, urban runoff, channelization, riparian removal, land application of manure, and sewage disposal.
TMDLs are established for phosphorus, sediment, fecal coliform bacteria, dissolved oxygen, ammonia, floodplain capacity, bedload, and habitat. Some of the recommended solutions to address the impairments include storm water controls, point source controls, manure management, and habitat improvements.
Since the TMDL was approved, Ohio EPA has developed an alternative general permit specifically for the Big Darby Creek for storm water associated with construction activity.
The TMDL Report
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 following documents provide background information on the Big Darby Creek watershed.
For more information contact:
Erin Sherer
Ohio EPA
Central District Office
50 West Town Street, Suite 700
P.O. Box 1049
Columbus, Ohio 43216-1049
e-mail: erin.sherer@epa.state.oh.us
telephone: (614) 728-3839