Stream Classification for TMDL Assessment Using a Dimensionless, Reference Reach Approach

Bruce Wilson, Professor
John Nieber, Professor
James Perry, Professor and Head, Fisheries and Wildlife
Bruce Vondracek, Professor, Fisheries and Wildlife
Joe Magner, Minnesota Pollution Control Agency
Greg Johnson, Minnesota Pollution Control Agency

Funding Source

U.S. Environmental Protection Agency – STAR Grant

Objective

The overall goal of the proposed project is to develop a simple classification system that is useful in TMDL assessment. Research objectives are to:

• Investigate the relationship between indicators of stream health and localized stream characteristics,
• Develop and evaluate dimensionless curves using reference reach values as a tool for stream classification and TMDL assessment, and
• Propose and test a stream classification system using the prediction intervals of the dimensionless curves.

Need or Impact

The classification system will be used by states to prioritize efforts related to TMDL programs. The approach is well suited for considerations of changes in land use and other watershed practices.

Project Status

Measured data from Minnesota streams collected by various government and non-government agencies and research institutions have been obtained for the research study. Considerable additional data have been collected on localized stream characteristics in the Redwood River and Snake River Basins. Regional regression relationships were obtained for three areas within Minnesota using indicators of stream health of dissolved oxygen, total suspended solids, and fish IBI. The suitability of obtaining a dimensionless representation will be obtained by defining the best reference reach for each of these areas.