FACT SHEET: The Bay-Delta Water Quality Control Plan
The San Francisco Bay-Delta was once one of the most dynamic ecosystems on Earth but is now facing ecological collapse.
• The Bay-Delta is the largest estuary on the West Coast of the Americas, blending freshwater from California’s Central Valley rivers with salt water to create a biologically rich ecosystem that hosts more than 500 species of fish and wildlife. It is a major stopover for birds on the Pacific Flyway, and serves as a migration corridor for salmon and other migratory fish.
• Naturally, half of the rain and snow that falls on California would drain out through the Bay-Delta to the ocean.
• The Bay-Delta is facing ecological collapse, largely due to the lack of freshwater inflow. In an average year, half of the water from the Central Valley is diverted for human uses. The salinity balance of the Bay-Delta has been altered to such a degree that it has impacted everything from plankton at the base of the food web all the way up to orcas that eat salmon in the Pacific Ocean.
• Problems caused by low flows extend up into river ecosystems. Low flows (1) make it hard for anadromous fish—such as salmon—to migrate from freshwater where they are born to the ocean, and then back again to spawn; (2) allow our Sierra streams to get too warm for native fish to be healthy; (3) don’t allow floodplains (critical habitat for baby fish) to get inundated; and (4) fail to dilute pollutants, such as agricultural pesticides and fertilizers.
• By altering our freshwater ecosystems so dramatically, humans have created conditions that favor non-native species that evolved in slow-moving, warm water—such as bass that feed on baby salmon—over native species.
• Salmon has received much of the attention, but the larger concern is over the decline of salmon-based ecosystems. Salmon transport millions of pounds of nutrients from the ocean to upland habitats where they feed more than 100 other species and fertilize soils for forests and meadows.
• Salmon also supports people and jobs. While there is still a commercial fishing industry in the Bay Area, it is on the brink of disappearing. The salmon population was so low in 2008 and 2009 that the fishing seasons had to be canceled. Related economic sectors, such as seafood markets and restaurants, also were heavily impacted.
The State is trying to restore the Bay-Delta ecosystem, but water agencies are fighting them.
• The State Water Resources Control Board oversees the Bay-Delta Water Quality Control Plan. It was first adopted in 1978, and updated in 1995, but it hasn’t been updated since—for more than a quarter-century.
• On December 12, 2018, the State Water Board deliberated on Phase 1 of the Bay-Delta Plan, which focuses on the San Joaquin River and its three major tributaries: the Tuolumne, Stanislaus, and Merced rivers.
• The adopted Phase 1 would require 40% of the unimpaired flow to remain in those rivers between February and June (critical months for baby fish), but has yet to be implemented.
• Despite the fact that humans would still be able to divert three out of every five gallons of water, a number of water agencies sued to block the plan, and it has been stalled ever since.
• Shockingly, the San Francisco Public Utilities Commission (SFPUC), which manages the Hetch Hetchy Reservoir in Yosemite National Park, and the Bay Area Water Supply and Conservation Agency (BAWSCA), which represents Hetch Hetchy water customers in San Mateo, Santa Clara and Alameda Counties, joined in suing the state. They are not representing the environmental values of their constituents.
• The water agencies have proposed an alternative to the Bay-Delta Plan, called a Voluntary Agreement, which would leave very little additional water in our rivers, and would fail to restore the Bay-Delta ecosystem. A peer review commissioned by the National Marine Fisheries Service found major flaws in the science behind the Voluntary Agreement.
• The Tuolumne River, where the SFPUC and BAWSCA get most of their water from Hetch Hetchy, is in the worst shape of all of California’s Central Valley rivers. Historically, the River hosted well over 100,000 salmon, but in 2020,
barely 1,000 returned to spawn. The Tuolumne desperately needs more water— in an average year only 21% of the unimpaired flow is currently left in the river between February and June.
The Bay Area will not run out of water, but we could easily run out of salmon and the species that depend on them.
• The SFPUC and BAWSCA have used scare tactics to trick community leaders into supporting their position. They have inflated demand projections and potential economic impacts, and are using a manufactured “design drought,” which combines the two worst droughts from the last century, to make the Bay-Delta Plan look extreme.
• In reality, the SFPUC could manage a repeat of the worst drought on record (1987-1992—six years), with the Bay-Delta Plan flows in place, without requiring any rationing or developing any new water supplies, such as recycled water. Through rationing and bringing alternative water supplies online, the SFPUC could manage an even more severe drought.
• Consider these facts: (1) The SFPUC has a lot of reservoir storage–enough to last six years; (2) in an average year, the SFPUC is entitled to three times as much water as it uses, so storage fills quickly; (3) at the height of the recent drought (2015), the SFPUC still had enough water in storage to last three years; (4) by the summer of 2016, the SFPUC had enough water in storage to last five years; and (5) by the summer of 2017, all of the SFPUC’s reservoirs were full, and they had to “dump” 10 years’ worth of water because they had no place to store it. The river ecosystem experienced one incredibly good year at the expense of five terrible years (2012-2016) when the river received an average of just 12% of its unimpaired flow.
• In an absolute worst-case scenario, the SFPUC could purchase water from an agricultural irrigation district in the San Joaquin Valley at full market value—and it would still be half the price we are used to paying for water.
Get involved.
Visit Our Revive The Tuolumne Page or email Peter Drekmeier at peter@tuolumne.org
Prepared by the Tuolumne River Trust