Aquatic Life Policy 10-1

Direct measurement and characterization of the health and well-being of the aquatic community in surface water are critical to determining how effectively Colorado is achieving the ultimate goals of the Colorado Water Quality Control Act (“CWQCA”) and the Federal Clean Water Act (“CWA”), which are to restore, maintain, protect, and improve the quality of our water resources. To this end, one of the specific policy goals of the CWQCA is the “protection and propagation of wildlife and aquatic life”. Policy 10-1 is the Colorado Water Quality Control Commission’s methodology for determining whether the aquatic life use is attained in rivers and streams.

From 2016 to 2017, the Water Quality Control Division worked with stakeholders to improve Policy 10-1, and the Water Quality Control Commission adopted the proposal in August 2017. The current iteration of Policy 10-1 expires on December 31, 2025.

The following proposals will be the focus of the Policy 10-1 stakeholder engagement process as possible enhancements:

  • Reference and stressed site lists were revised – re-evaluate metric performance and determine if MMIs should be revised
  • Possibly modify biological thresholds
  • Investigate site classifications or Biotypes – potentially split Biotype 1 into East and West
  • EDAS usability - port EDAS to a more contemporary Microsoft Office Access version

Stakeholders will review past updates and analyze the division's anticipated technical work with Tetra Tech.

The division invites water quality professionals and the general public to join the division's continued efforts to improve Policy 10-1. Participation in the larger stakeholder workgroup is open to all interested parties. Participation in the narrowed Technical Advisory Committee (TAC) is open to scientific and water quality professionals, spanning local, state, federal, non-governmental organizations, and academia, who are experienced in the field of benthic macroinvertebrates and development of Colorado’s bioassessment tools.