Save the Illinois River, Inc.
24369 E 757 Rd.
Tahlequah, OK 74464-1949
(918) 284-9440

2020 CY Water Quality Monitoring Report Illinois River Basin

Water Quality Monitoring Report for the Illinois River Basin CY 2020 Presented to the Arkansas-Oklahoma Compact Commission, September 2021

Oklahoma delivered its Illinois River Water Quality Report to the Arkansas-Oklahoma Arkansas River Compact Commission on September 23, 2021.


Oklahoma's phosphorus limit of 0.037 mg/L, adopted in 2020, continues to be exceeded at the state border with Arkansas at Watts, Oklahoma and downstream at Tahlequah, Oklahoma.

Oklahoma is not enforcing the 0.037 mg/L phosphorus limit for state scenic rivers and, instead, is attempting to reach an agreement with Arkansas on voluntary phosphorus control measures including best management practices (BMPs).

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The Illinois River watershed in Arkansas and Oklahoma