The Illinois River, a designated Oklahoma Scenic River
Following are select data from the 2024 Arkansas River Compact Commission showing the Illinois River watershed water quality reports of Oklahoma and Arkansas.
Take away message from the 2024 report: Oklahoma's phosphorus limit of 0.037 mg/l total phosphorus is exceeded at the state line and at Tahlequah. The Illinois River and Lake Tenkiller are impaired by phosphorus and are not meeting Oklahoma's water quality goals.
Oklahoma's limit for phosphorus for the Illinois River is exceeded by 99-percent at Watts, Oklahoma and by 92-percent at Tahlequah, Oklahoma.
Impairments of Water Quality of the Illinois River and to Lake Tenkiller
Phosphorus Levels at Watts, Oklahoma
Phosphorus Levels at Tahlequah, Oklahoma