The Bay Institute Releases 'Gone with the Flow' Primer on Freshwater Flows as California Legislators Consider Need for Major New Delta Flow Improvements

Aug 09, 2010, 16:52 ET from The Bay Institute

NOVATO, Calif., Aug. 9 /PRNewswire/ -- Today, as the California Senate considers major new recommendations to increase freshwater flows to the San Francisco Bay-Delta estuary, the Bay Institute released Gone with the Flow, a primer on how flows support a healthy ecosystem, and how the lack of flow is degrading that ecosystem to the point of collapse.  The primer is available for free at

"Flow is the most important driver of ecosystem health in the Bay-Delta system, and the science regarding the effects of flow on species and habitats is stronger and better documented than for most other factors," said Gary Bobker, program director for The Bay Institute. "The story of how flows shape the actual physical habitats and support the processes that underlie the survival, reproduction and migration of so many species from the higher elevation mountain streams to the Bay is a story that needs to be understood by the widest possible audience."

Gone with the Flow describes in plain language how runoff flowing from the mountain watersheds ringing California's Central Valley provided coldwater paradises for salmon returning to their native streams; turned lowland rivers and their floodplains into a rich source of food and shelter for young fish; mingled in the Delta's complex maze of marshes and sloughs; and created a vast expanse of brackish water habitat essential for estuarine creatures in the upper reaches of San Francisco Bay. The primer also explains how the lack of access to most upland streams now forces migratory fish to cope with undesirable, often lethal flow conditions; how runoff in lowland rivers has been shifted from spring to summer, or even almost completely cut off in the San Joaquin basin, with disastrous consequences for the environment; how reverse flows in Delta channels kill hundreds of millions of aquatic organisms each year; and how the Bay is now in a permanent ecological drought because of the diversion of half its freshwater inflow.

"There is no compelling evidence that anything other than restoring flows will save the Bay-Delta ecosystem," said The Bay Institute executive director and chief scientist Dr. Christina Swanson. "There are many alternative explanations put forward to explain the collapse of the Bay-Delta's fisheries and habitats, but none are as well-documented as the explanation that freshwater flow is the indispensable element in defining and maintaining the health of an estuary like the Bay-Delta."

Gone with the Flow describes some of these alternative factors, such as wetland loss, toxic runoff, predation, and ocean conditions, and explains why none of them takes the central place of flows in understanding the collapse of the Bay-Delta ecosystem. The primer also summarizes the flow restoration measures necessary to save the estuary and how the state's water supply needs can be fully met while restoring flows.

Dr. Swanson and Mr. Bobker will be testifying today at the invitation of the California Senate Select Committee on Delta Conveyance, Conservation, and Governance. The Committee is considering a major new report on Delta flow criteria adopted by the State Water Resources Control Board on August 3 in response to a mandate from the legislature in the Delta Reform Act of November 2009. The report recognizes that the Delta is getting far less water than is needed to protect its ecosystem, and recommends new flow criteria that would significantly improve conditions in the estuary, based in large part on analyses and recommendations developed by The Bay Institute.

About The Bay Institute

The Bay Institute is the leader in protecting, restoring and inspiring conservation of San Francisco Bay and its watershed — from the Sierra to the sea. For nearly 30 years, The Bay Institute has been developing and leading model scientific research, habitat restoration, education and advocacy programs to preserve California's most important natural resource. Learn more at

SOURCE The Bay Institute