Ever since February, over the protests of The Bay Institute, the state of California has cut back on ecologically vital freshwater flows into the Sacramento-San Joaquin Delta and San Francisco Bay. These flows are critical to the survival of estuarine and migratory fish species that are at high risk of extinction, as well as for commercial and recreational fisheries for species such as starry flounder and fall-run Chinook salmon. Part of the state’s rationale for weakening these flow requirements was to save water in upstream reservoirs operated by the federal Bureau of Reclamation to maintain coldwater spawning habitat for salmon.
Last year, Reclamation argued for and implemented the same strategy of trading required fresh water flows downstream for improved habitat conditions upstream; but that strategy failed with disastrous consequences for salmon and other imperiled native fish species.
After monitoring dam operations, The Bay Institute and the Natural Resources Defense Council warned the State Water Resources Control Board in May that too much water was being released and delivered to irrigaion districts with senior water rights to maintain adequate coldwater storage. The Board subsequently ordered Reclamation to correct the situation.
But over the past two months, releases from Shasta Reservoir have remained higher than necessary for temperature control with potentially disastrous results for imperiled winter- and spring-run Chinook salmon and the commercially valuable fall Chinook salmon run. Reclamation’s modeling is notorious for underestimating temperature impacts and overestimating the amount of water available for delivery to large irrigators, rendering their assurances about protecting salmon habitat below federal dams meaningless. As a result, it is increasingly likely that Chinook salmon eggs, juveniles, and adults will be exposed to lethal temperatures in the narrowly constricted area of spawning habitat that remains below Shasta Dam. This would be the third bad year in a row for Chinook salmon on the Sacramento River; Reclamation’s mismanagement of water temperatures last year resulted in loss of 95% of the 2014 year class of winter-run Chinook salmon – and the outcome for fall-run may have been even worse.
Meanwhile, during the same period, Reclamation continued to deliver water to senior water rights irrigators on the Stanislaus River. This reduced the amount of coldwater storage in the New Melones Reservoir available to maintain spawning habitat for the declining fall run of San Joaquin River Chinook salmon. Now Reclamation has petitioned the State Water Board to weaken the water quality standards for dissolved oxygen (D.O.) on the river, from 7 milligrams per liter to 5 mg/L – well below the threshold needed to avoid severe distress or mortality for fish. In our protest, The Bay Institute has warned that relaxing the D.O. standard would likely ensure the destruction of the 2015 year class of the fall-run on the Stanislaus, as well as creating a barrier to adult fall-run salmon attempting to migrate up the lower San Joaquin River to spawn on the Stanislaus and other tributaries.
WHAT YOU CAN DO: It’s outrageous that the U.S. Bureau of Reclamation has managed to provide the worst possible outcome for our priceless and endangered salmon runs and other fish species of concern for two years in a row.
- Protect fall- and spring-run San Joaquin River Chinook salmon by denying Reclamation’s petition to weaken the dissolved oxygen standard on the Stanislaus River;
- Protect winter, spring, and fall runs of Chinook salmon on the Sacramento River by requiring Shasta Reservoir operations that maximize the benefits of the limited cold water that remains;
- Aggressively assert its authority to ensure that Reclamation and other water agencies cannot continue to sacrifice the estuary’s unique fish populations.
This article was previously published by The Bay Institute From the Sierra to the Sea: http://thebayinstitute.org/robbing-peter-and-paul