Total Maximum Daily Load (TMDL)
DEQ manages the Total Maximum Daily Load (TMDL) program for the State of Oklahoma. A TMDL is the process of establishing the sources of impairment in a given waterbody, whether from point sources (discharges) or non-point sources (runoff), determining the amount of reduction necessary to meet water quality standards in that waterbody, and allocating the loads to the various contributors of pollution. A margin of safety is also included in the TMDL calculation process.
Water quality modeling is the linkage between the sources of pollution and the instream water quality of a given waterbody. A model is a representation of the water-quality processes that occur in a given waterbody. Water quality modeling can be resource-intensive. Different levels of complexity may be used depending on the level of confidence required in a given situation.
Wister Lake Draft TMDL Report and Public Notice
Please submit comments in writing to: Soojung Lim, Water Quality Division, Oklahoma Department of Environmental Quality, PO Box 1677, Oklahoma City, OK 73101-1677
or by email at Water.Comments@deq.ok.gov
Public Notice for the Wister Lake TMDL – Comment period closes January 6, 2025
Wister Lake TMDL Modeling Report
Wister Lake Draft TMDL 208 Fact Sheet
Washita River Basin Bacteria and Turbidity TMDL Public Notice
The 2024 Bacteria and Turbidity Draft TMDL for the Washita River Basin is open for Public Comment through 4:30 pm on Friday, November 22, 2024.
Please submit comments in writing to: Soojung Lim, Water Quality Division, Oklahoma Department of Environmental Quality, PO Box 1677, Oklahoma City, OK 73101-1677
or by email at Water.Comments@deq.ok.gov
Washita River Basin Bacteria and Turbidity TMDL Public Notice – Comment Period ends Friday, November 22, 2024.
208 Factsheet for the Washita River Basin TMDLs
Draft Washita River Basin Bacteria and Turbidity TMDL Report
Revised Lower Red River- Little River Basin Study Area TMDL Public Notice
The Revised Lower Red River – Little River Basin Study Area Draft TMDL for Bacteria and Turbidity is open for Public Comment through 4:30 pm on Monday, October 28, 2024.
Please submit comments in writing to: Soojung Lim, Water Quality Division, Oklahoma Department of Environmental Quality, PO Box 1677, Oklahoma City, OK 73101-1677
or by email at Water.Comments@deq.ok.gov
Idabel Wasteload Allocation and Revised TMDL Public Notice – Comment Period ends Monday, October 28, 2024.
Idabel Public Works Authority Draft Wasteload Allocation Report
Draft Revised Lower Red River – Little River Basin Study Area Draft TMDL for Bacteria and Turbidity
Lake Oologah TMDL Report
Public Notice for the Lake Oologah Draft TMDL
Lake Oologah Draft TMDL Report
Appendix A – Data Acquisition and Assessment
Appendix B – Watershed Model Calibration and Validation Report
Appendix C – EFDC Hydrodynamic and Water Quality Model
Appendix D – Oklahoma Antidegradation Policy
Appendix E – Water Withdrawals in Verdigris River Basin
Appendix F – Sanitary Sewer Overflow Bypass Events
Appendix I – Ambient Monitoring Data at Watershed and Lake Stations
Appendix J – Stormwater Permitting and BMPs
Fort Gibson Lake TMDL Report
Public Notice for the Fort Gibson Lake Draft TMDL
Fort Gibson Lake TMDL – EPA Approval Letter
Fort Gibson Lake Draft TMDL Report
Appendix A – HSPF Watershed Model
Appendix C – Antidegradation Policy
Appendix D – Ambient Monitoring Data
Appendix E – Stormwater Permitting and BMPs
Appendix F – SSO Bypass Events
Appendix I – Distributions for Maximum Daily Loads
Fort Gibson Lake 208 Factsheet
Contact Watershed Planning
An interactive map of Oklahoma’s waterbodies is available at http://gis.deq.ok.gov/maps/.