Chetco River - Pollution

Pollution

The Oregon Department of Environmental Quality (DEQ) has monitored the Chetco River for eight different parameters that affect water quality: temperature, oxygen saturation, pH, nutrients, bacteria, chemical contaminants such as pesticides and metals, turbidity, and alkalinity. Streams that exceed the standard level are then placed on the DEQ 303d list in accordance with the Clean Water Act. The Chetco from Box Canyon Creek to its mouth exceeded the standard level for temperature and turbidity. The North Fork, South Fork, and other tributaries were also listed for temperature and turbidity. All tributaries of the Chetco usually exceed the 64 °F (18 °C) temperature standard. Water temperatures range from 62.6 °F (17.0 °C) at Bosley Creek to 76 °F (24 °C) at Willow Bar. High turbidity levels in the Chetco River watershed are usually caused by landslides, various forms of erosion, and plugged road culverts.

On the Oregon Water Quality Index (OWQI) used by DEQ, water quality scores can vary from 10 (worst) to 100 (ideal). The average for the Chetco River at RM 10.8 (RK 17.4) between 1998 and 2007 was 95 (excellent) in the summer and 90 in the fall, winter, and spring. These scores are comparable to the 1986 to 1995 results of 94 and 93. Despite the excellent ratings, the Chetco River actually ranks as the second most polluted stream in Curry County, after nearby Floras Creek, a tributary of the New River.