Bioassessment and Biocriteria Program Status for Oregon: Streams and Wadeable Rivers
State Program Contact
Oregon Department of Environmental Quality Exit
Water Quality Standards
The link to Oregon's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
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They vary by basin and include:
Salmon and Steelhead Migration Corridors
Salmon and Steelhead Spawning through Fry Emergence
Shad and Sturgeon Spawning and Rearing
Redband or Lahontan Cutthroat Trout
Cool Water Species (No Salmonid Use)
Redband and Hybrid Trout
Borax Lake Chub
Bull Trout Spawning and Juvenile Rearing
Core Cold Water Habitat
Salmon and Trout Rearing and Migration
__X__ Narrative, with quantitative implementation procedures or translators
_____ No criteria
Waters of the State must be of sufficient quality to support aquatic species without detrimental changes in the resident biological communities.
Use of biocriteria or bioassessment not included in antidegradation policy.
What biological assemblages are used in the bioassessment program?
Benthic macroinvertebrates, fish, and amphibians
Are bioassessments used to support 303(d) listings?
Yes. Listing methodology: Methodology for Oregon’s 2018 Water Quality Report and List of Water Quality Limited Waters (PDF) (109 pp, 3 MB)
How are assemblages used to make impairment decisions?
Only macroinvertebrate data is used to make impairment decisions.
Other uses of biocriteria or bioassessment within the water quality program:
TMDL development and assessment, non-point source assessments, BMP evaluation, 305(b) surface water condition assessments, and restoration goals
Technical Support Information and Documents:
The paper below describes the approach the Oregon DEQ Watershed Assessment Section uses to select reference condition sites. The purpose of selecting reference condition sites is to establish an objective and systematic method for finding water bodies minimally disturbed by human activities.
Technical reference material:
An Approach for Biological Criteria and Watershed Assessment
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:
PREDATOR: Development and use of RIVPACS-type macroinvertebrate models to assess the biotic condition of wadeable Oregon streams (November 2005 models)
Stressor identification/causal analysis approach: