Surface Water Quality Standards

The Surface Water Quality Standards team works to develop adequate and appropriate standards to protect Wyoming’s surface waters, which include:

  • Rivers

  • Streams

  • Lakes

  • Reservoirs

  • Wetlands

Program Responsibilities 

We combine scientific data with public input on the use of surface waters to develop criteria to to protect and restore Wyoming’s surface waters for current and future generations.

Our current Surface Water Standards were updated on Sept. 24, 2013, and are available as state rules, Chapter 1. Implementation policies for antidegradation, mixing zones and dilution allowances, turbidity, and use attainability analyses also became effective September 24, 2014.

Surface Water Designated Uses

Surface water designated uses are assigned to Wyoming’s surface waters through a hierarchical classification system. To determine the class and designated uses that apply to particular surface waters in Wyoming, use the Wyoming Surface Water Classification List. Changes to classifications and designated uses are made through a formal process and are based on a scientific assessment called a use attainability analysis (UAA). Changes to classifications and designated uses for Wyoming surface waters can be viewed here.


Since approximately 2009, DEQ has been working with the public to develop a Categorical Use Attainability Analysis for Recreation to identify low flow channels in the state where swimming or similar water contact activities (i.e, primary contact recreation) are not attainable or existing uses. Waters not used for swimming or similar water contact activities are designated for secondary contact recreation. On September 1, 2016, the Water Quality Division Administrator made a final determination regarding the recreation designated uses changes. The designations will be submitted to the Environmental Protection Agency pursuant to the federal Clean Water Act. Recreation designations can be determined using the Recreation Designated Uses Web Map.