Streamflow and Water Pollution—the Shasta River

October, 2015


Streamflow and Water Pollution—the Shasta River

The answer to pollution is dilution. This famous saying expresses a fundamental truth: a stream’s water quality and flow are intertwined and cannot be separated. 

Let’s consider the Shasta River as an example. The North Coast Regional Water Quality Board (North Coast Board) designated the Shasta River as “impaired” with respect to water temperature and dissolved oxygen in the early 1990s. Eventually—and only after a lawsuit by environmental groups—the North Coast Board conducted a study to identify the sources of impairment and an implementation plan to clean-up the pollution and restore those beneficial uses, including ESA-listed Coho and at-risk Chinook Salmon, as required by the federal Clean Water Act and the state Porter Cologne Act,  The Shasta TMDL (Total Daily Maximum Load) and Implementation Plan was adopted in 2006.

The study found that the temperature of Shasta River water could be reduced low enough to support salmon and other beneficial uses if Shasta River flows were increased by 45 cubic feet per second. The Shasta TMDL Implementation Plan calls for that flow increase to be achieved by those who divert water from the River and its tributaries employing “water management practices and activities that result in increased dedicated cold water instream flowing the Shasta River and its tributaries.” 

The plan calls for those diverting water from the river and its tributaries to report to the Regional Water Board on “documenting dedicated cold water instream flow in the Shasta River in relation to the 45 cfs goal or alternative flow regime that achieves the same temperature reductions from May 15 to October 15.”

The report was due in 2002, but there is no evidence that it has ever been filed.
The deadline for achieving the required 45 cfs increase in river flows through voluntary means was also 2002. If the flow increase was not achieved, the Implementation Plan states that the Water Board:

“May recommend that the State Water Board consider seeking modifications to the decree, conducting proceedings under the public trust doctrine, and/or conducting proceedings under the waste and unreasonable use provisions of the California Constitution and the California Water Code.”

Needless to say, the “required” 45 cfs increase in Shasta River flows has not been achieved. Nor has  the Water Board recommended modification of the Shasta River water right adjudication decree. The Board’s Executive Officer has not even informed the North Coast Board that Shasta River flows, and the beneficial uses those flows support, remain impaired.
As this report was written, Shasta River flows were a pitiful 24 cfs. No doubt those who divert water from the River would blame the drought. However, measurements of Shasta River flows over time by the US Geological Survey near the River’s mouth indicates that the flows have been very similar year after year since the USGS first began measuring the flows in 2007. This is because the Shasta River flows derive mostly from large volcanic springs rather than snowmelt. Volcanic springs are little affected by short term changes in precipitation or snow pack.


All our hikes are open to the public. Contact hike leaders for more information:

Saturday, October 24—North Group Sierra Club Lacks Creek/Pine Ridge Prairies Hike. Explore this nearby Bureau of Land Management area off Highway 299, on new and old trails created by BLM, Humboldt Trails Council, and Redwood Coast Mountain Bike Association. See a mix of oak savannas, old-growth conifers, and regenerating hardwood-covered slopes. Bring lunch and water.Dress for a fall day at 3,600 feet elevation. Medium difficulty, five miles, less than 1,000 ft. elevation change. Carpools: Meet 9 a.m. Ray’s Market in Valley West, trailhead 10 a.m. Leader Ned,, 707-825-3652. Heavy rain cancels.
Saturday, November 14—North Group Sierra Club Humboldt Redwoods State Park Avenue of the Giants Hike. Two separate trails, about a mile apart, take us to a view of the Eel River from High Rock (an actual rock along the river), and to a grove of stately redwoods about 1,000 feet above. Fall colors. Band-tailed Pigeons? Bring lunch and water. Medium difficulty, 5 miles, 1,000 ft. elevation change. Carpools: Meet 9 a.m. at Herrick Avenue Park & Ride in Eureka. Leader Ned,, 707-825-3652. 

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