Wyoming Finalizes Its First Stream Mitigation Procedure

The United States Army Corps of Engineers Omaha District Wyoming Regulatory Office has approved the first Wyoming Stream Mitigation Procedure (WSMP) for the state.

The WSMP establishes a method for calculating compensatory mitigation debits and credits that will provide predictability and consistency. Such a procedure is necessary for allowing the development of mitigation banks in the state. The practice of using compensatory mitigation to minimize unavoidable losses of aquatic resources is an important component of the U.S. Army Corps of Engineers (Corps) Clean Water Act Section 404 Regulatory Program.

According to the WSMP document, Wyoming’s procedure was adapted from similar methodologies used in other Corps Districts that have been in effect for several years, and is based on the Montana Stream Mitigation Procedure originally drafted a decade ago, but updated this year as well.

The idea of mitigation banking has been around for 30 years, and has steadily gained ground as a preferred method of protecting aquatic resources. In 2008, the EPA and the Corps issued revised regulations governing compensatory mitigation. The 2008 Compensatory Mitigation Rule (22 CFR Parts 325 and 332) established equivalent and effective standards for all three compensatory mitigation mechanisms: mitigation banks, in-lieu fee mitigation, and permittee-responsible mitigation. Since mitigation banking is the most reliable form of compensatory mitigation, these regulations establish a hierarchy for the use of banks when appropriate credits are available.

Mitigation bank credits may be purchased by a permittee from a mitigation bank where aquatic resources (e.g., wetlands, streams, riparian areas) are restored, established, enhanced, and/or preserved in advance of impacts.

The WSMP represents an important step forward for Wyoming’s aquatic resources.