Freshwater Flows and the San Francisco Bay-Delta Estuary
San Francisco Bay and Delta–where fresh and salt water meet and mix–form the largest estuary on the west coast of North America. The mixing of salt water from the Pacific Ocean and fresh water from the Sacramento and San Joaquin Rivers creates brackish water habitat unique to estuaries. It’s this mixture of waters that for centuries sustained legendary salmon runs, shellfish beds, tremendous shorebird migrations, eelgrass meadows, and other natural riches.
The vitality of the San Francisco Bay-Delta Estuary depends on a healthy and dynamic balance between ocean water and fresh water. Over the past several decades, however, larger and larger quantities of fresh water have been diverted for human use from the Sacramento-San Joaquin River watershed, which drains into the Estuary. As a result, this balance has been lost, with devastating impacts to the ecosystem and to certain segments of the economy. Increasing and improving the timing of freshwater flows through the Bay-Delta is essential to restoring the health of the San Francisco Bay-Delta Estuary.