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Bioassessment and Biocriteria Program Status for Oklahoma: Streams and Wadeable Rivers

State Program Contact

Oklahoma Water Resources Board Exit

Water Quality Standards

WQS Information
The link to Oklahoma's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
The state of Oklahoma provided information and links to sections of their administrative code on designated aquatic life use, biological criteria, antidegradation as well as technical support documents and information on its bioassessment and biocriteria programs. These are included for your convenience and may or may not reflect the most recently EPA approved WQS. The following links exit the site Exit

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Designated Aquatic Life Uses
Aquatic life uses are protected under the Fish and Wildlife Propagation beneficial use, which has four subcategories. Beneficial use designations are based on multiple thresholds including, fishery (warm vs cold water), habitat, chemistry, and benthic community.
  • Habitat Limited Aquatic Community
  • Warm Water Aquatic Community
  • Cool Water Aquatic Community
  • Trout Fishery (seasonal)

Biological Criteria
__X__ Narrative, with quantitative implementation procedures or translators
_____ Numeric
_____ No criteria

785:45-5-12. Fish and wildlife propagation
(f) Criteria used in protection of fish and wildlife propagation (5) Biological Criteria

  1. Aquatic life in all waterbodies with the beneficial use designation of Fish and Wildlife Propagation (excluding waters designated "Trout, put-and-take") shall not exhibit degraded conditions as indicated by one or both of the following:
    1. comparative regional reference data from a station of reasonably similar watershed size or flow, habitat type and Fish and Wildlife beneficial use subcategory designation or
    2. by comparison with historical data from the waterbody being evaluated.
  2. Compliance with the biological criteria to protect Fish and Wildlife Propagation set forth in this paragraph shall be based upon measures including, but not limited to, diversity, similarity, community structure, species tolerance, trophic structure, dominant species, indices of biotic integrity (IBI's), indices of well being (IWB's), or other measures.

Antidegradation Policy
Biocriteria plays an integral role Oklahoma’s antidegradation policy. The antidegradation requirements under Oklahoma Water Resources Board 785:45-3-2 requires criteria related to fish and wildlife propagation uses for Outstanding Resource Waters (Oklahoma’s Tier 3 waterbodies) and High Quality Waters (Oklahoma’s Tier 2 waterbodies) to be higher than Tier 1 (i.e. beneficial use baseline).

Outstanding Resource Waters are described as having “exceptional recreational and/or ecological significance” (785:45-3-2(a)).

High Quality Waters are described as: “those waters of the state whose historic water quality and physical habitat provide conditions suitable for the support of sensitive and intolerant climax communities of aquatic organisms whether or not that waterbody currently contains such a community, support high levels of recreational opportunity, and are designated "HQW" waters in Appendix A of this Chapter. These waters will generally have higher quality habitat, a more diverse and more intolerant biotic community and, as a result, may provide more ecological refuges and recreational opportunities than other waters in the same ecoregion with similar chemistry and physical conditions.” (785:45-3-2(b)).

Biological Assessment

What biological assemblages are used in the bioassessment program?
Benthic macroinvertebrates and fish

Are bioassessments used to support 303(d) listings?
Yes. Listing methodologies: Oklahoma’s Use Support Assessment Protocols at 785:46-15-5(i) (PDF) (50 pp, 529 K); Continuing Planning Process 2012 Version (PDF) (203 pp, 5 MB)

How are assemblages used to make impairment decisions?
Fish and benthic macroinvertebrate assemblages are independently applied in accordance with procedures outlined in the Continuous Planning Process (CPP) Document.

Other uses of biocriteria or bioassessment within the water quality program:
Refining ALU, non-point source assessments, BMP evaluation, 305(b) surface water condition assessments, and restoration goals.

Technical Support Information and Documents:

Reference condition:
For part of the bioassessment methodology, the reference data are based upon Oklahoma Conservation Commission’s review, evaluation, and determination of High Quality sites. 

Technical reference material:
Analysis of Oklahoma Conservation Commission Physicochemical and Biological Data Toward Determination of High Quality Sites (PDF)(86 pp, 1 MB)
Stream Assessment to Fill Data Gaps for Southwestern Oklahoma: Phase II
Stream Assessment to Fill Data Gaps for Eastern Oklahoma - Supplemental

Development of biocriteria involves the collection and interpretation of biological data –e.g. benthic macroinvertebrates, fish, and periphyton. During this process entities typically use biological metrics (usually aggregated into a multimetric index) and/or multivariate analysis to assess whether a waterbody is meeting its designated aquatic life use(s). The reference materials included below include standard operation procedures used in data collection, compilation, technical approaches used to develop biocriteria as well as its implementation procedures.

Technical reference material:
Implementation of Oklahoma's Water Quality Standards (PDF) (49 pp, 407 K) (46-15-5(i) & Appendix C)
Continuing Planning Process 2012 Version (PDF) (203 pp, 5 MB)
Oklahoma Water Resources Board: SOP’s for Monitoring and Assessment
Oklahoma Conservation Commission: SOP’s for Water Quality Monitoring and Measurement Activities (PDF) (244 pp, 5 MB)

Stressor identification/causal analysis approach: 
Use of statistical survey monitoring data and employed analytical methodology such as relative and attributable risk.

Technical reference material:

For more information on Oklahoma Water Resources Board Reports:
Oklahoma Water Resources Board Technical Reports

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