TMDL Status


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Colorado 303(d) Lists

Colorado 303(d) Lists

Identification of Water Quality Limited Waters

State water quality standards are the "yardstick" by which the State assesses the status of the water body or stream segment. The State compares recent information regarding the physical, chemical and biological condition of a stream segment with the associated water quality standards for that stream segment. Where Technology-based effluent limits in discharge permits alone are not stringent enough to assure that water quality standards are met, these stream segments are designated "Water Quality Limited" and added to the 303(d) List. This list is produced every two years. The 303(d) list includes the identification of the specific component (such as nitrate, copper, sediment or habitat) that further identifies the specific water quality problem for that segment. TMDLs are required for all components listed for each stream segment on the 303(d) List.

Priority Ranking and Targeting

Once the total list is developed, the State prioritizes the list of stream segments using a ranking process. The ranking considers such issues as: the risk to human health and aquatic life; vulnerability or fragility of a particular water body as an aquatic habitat; and immediate need for waste load allocation for permits or other programmatic needs.

1998 Section 303 (d) List

Notice of Suspension of Year 2000 303(d) List Development Process

Year 2002 303(d) Listing Methodology as revised August 12, 2002

Water Quality Limited Segments Still Requiring TMDLs – Colorado’s 2002 303(d) List and Monitoring and Evaluation List

Colorado 2003 Section 303(d) List Supplement (Approved March 11, 2003)

Section 303(d) Listing Methodology for 2004

March 17, 2004 Final 303(d)/Monitoring and Evaluation Lists (Regs. #93 & #94)