The Illinois River is a multi jurisdictional tributary of the Arkansas River, approximately 100 miles (160) km) long, between the States of Arkansas and Oklahoma. The Illinois River begins in the Ozark Mountains in the northwest corner of Arkansas (Washington County) and flows west into northeast Oklahoma. Once the Illinois River enters Oklahoma, it then flows southwest and south through the mountains of eastern Oklahoma into Tenkiller Ferry Lake. The Illinois River in Oklahoma is currently on the 303(d) list for total phosphorus, while tributaries to the Illinois River (e.g. Osage Creek, Muddy Fork, and Spring Creek) in Arkansas are also on the 303(d) list for total phosphorus.
Current Phase – Watershed and Lake Calibration/Validation Modeling
The calibration/validation modeling is currently being conducted for both Illinois River and Lake Tenkiller. The purpose of the calibration/validation modeling is to ensure a scientifically sound modeling system is developed to represent the entire Illinois River Watershed. Calibration modeling will be performed using data obtained from the time period of 2001 to 2009, whereas data obtained from the 1992 to 2000 period of record will be used for validation modeling. Calibration and validation of the Illinois River Watershed models will be achieved by considering qualitative and quantitative measures, involving both graphical comparisons and statistical tests.
NEW: Notice of Informational Meeting:
Cherokee Nation will be hosting an informational meeting on November 14, 2013, at 6 pm. At the meeting, EPA will update the public on the Illinois River Watershed Modeling and TMDLs development project. The meeting will be held in the Cherokee Casino, located at 2416 Hwy 412 in Watts, Oklahoma 74964. The meeting will include presentations on the Illinois River Watershed Modeling effort to date and a question and answer session. For additional information, contact Diane Smith at 214-665-2145 or Smith.Diane@epa.gov.
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Technical Workgroup Meeting/Conference Calls
January 17, 2013 Conference Call
November 8,2012 Springdale, AR Technical Meeting
Core Group Meeting/Conference Calls
October 3, 2012 Conference call
August 24, 2012 Conference call
November 14, 2013 Meeting
November 8, 2012 Meeting
April 26, 2012 Meeting
May 19, 2011 Meeting
January 6, 2011 Meeting
September 14, 2010 Meeting
February 4, 2010 Meeting
November 20, 2009 Meeting - Project Kickoff Meeting