Water Quality Monitoring


In February 2009, the Regional Board approved the Coalition’s first comprehensive Management Plan, which details the Regional Plan of Action to address multiple exceedances of water quality parameters at a given site within a three-year period. Within the Coalition’s ten subwatersheds, sitespecific management plans for registered pesticides and toxicity receive the highest priority for implementation with legacy pesticides and trace metals a medium priority and salinity (including conductivity and TDS), dissolved oxygen, pathogens, and pH a low priority, since these parameters have the highest number of potential non-agricultural sources and causes

Colusa Glenn Subwatershed Monitoring Sites:

Colusa Basin Drain above Knights Landing (COLDR)

This site is near the outfall gates of the Colusa Basin Drain before its confluence with the Sacramento River. This site is downstream of all of the other monitoring sites within the basin. The upstream acreage consists of almonds, tomatoes, wetlands, pasture, corn, and walnuts. Monitoring at this site is coordinated with the California Rice Commission.

Freshwater Creek at Gibson Road (FRSHC)

The Freshwater Creek drainage includes approximately 83,000 total acres. Irrigated acreage (excluding rice acreage) is approximately 19,000 acres. Predominant crops in the drainage are rice, tomatoes, idle acreage, squash, grain, pasture, and safflower.

Stony Creek on Hwy 45 near Rd 24 (STYHY)

This site characterizes water from the contributing area downstream of Black Butte Reservoir just north of the town of Orland and includes approximately 20,000 acres of irrigated lands. The major irrigated crops in the Lower Stony Creek drainage are pasture, almonds, prunes, and wheat.

Walker Creek near 99W and CR33 (WLKCH)

The Walker Creek drainage is located east of Wilson Creek in Glenn County, and the Walker Creek monitoring site is located 1.3 miles north of the Town of Willows. The Walker Creek drainage includes approximately 27,000 total irrigated acres. Predominant crops in this drainage are almonds, rice, corn, and alfalfa. This is a representative site for this subwatershed.