EPA Finishes Models of Illinois River Watershed

The U.S. EPA has completed the Illinois River Watershed Basin and Lake Tenkiller models and released them to the partnering agencies for use. EPA partnered with Arkansas, Oklahoma and the Cherokee Nation to develop science-based water quality models. Partner agencies can now use the models to evaluate options as they continue to reduce phosphorus loadings from sources in northeast Oklahoma and northwest Arkansas.

“These tools are great examples of how cooperative federalism works by helping partnering agencies achieve their long-term goals,” said EPA Regional Administrator Anne Idsal. “Over the years we have made great progress by working with states, tribes and local agencies in improving conditions throughout the watershed and we look forward to continuing this effort.”

The models simulate conditions within the Illinois River Watershed and in Lake Tenkiller. These models can be used to evaluate options and their ability to improve water quality. EPA completed calibration as well as a sensitivity and uncertainty evaluation for the watershed and lake models. Within a few weeks, the EPA will convene the partnering agencies to share information about both models and discuss next steps.

Both states have committed to sharing the models and information with stakeholders within the impacted areas and will encourage feedback and involvement within their jurisdictions. Partner agencies will continue to collaborate during the coming months.

Since 2003, Arkansas and Oklahoma have been working cooperatively to protect and improve water quality in the designated scenic rivers and to avoid costly, protracted litigation and administrative proceedings. In February 2013, Arkansas and Oklahoma extended and augmented the original Statement of Joint Principles and Action to make additional commitments to further scientific understanding and continue to improve water quality through 2016. Today’s release of the two models is expected to help partnering agencies continue this progress.

Nutrient pollution is one of America’s most widespread, costly and challenging environmental problems, and is caused by excess nitrogen and phosphorus in the air and water. Phosphorus levels in the Illinois River can be caused by various types of city and industrial discharges as well as nonpoint source runoff. The downstream impacts to Lake Tenkiller may include ‘algal blooms’ and low dissolved oxygen concentrations in the lake.

Source: EPA News Release