Header link June 22, 2020

LinkedIn

  • Read more
Header link September 15, 2014

Cart

  • Read more
Header link November 3, 2015

Donate Now

  • Read more
Header link May 15, 2014

Twitter

  • Read more
Header link May 15, 2014

Facebook

  • Read more
Instagram
Header link May 15, 2014

Instagram

  • Read more
Header link May 15, 2014

Contact Us

  • Read more
More options
Water Education Foundation
Home

Water Education Foundation

Everything about California water that matters
  • Water Academy
    • Agriculture
      • Agricultural Conservation
      • Agricultural Drainage
    • Background Information
      • Legislation — California and Federal
      • Regulations — California and Federal
      • Water History
      • Water Rights
    • Bay-Delta
      • Bay Delta
      • Bay Delta Conservation Plan
      • Delta Issues
      • Delta Smelt
      • Sacramento San Joaquin Delta
      • San Francisco Bay
      • Suisun Marsh
    • Dams, Reservoirs and Water Projects
      • California Aqueduct
      • Central Valley Project
      • Folsom Dam
      • Friant Dam
      • Hetch Hetchy
      • Hoover Dam
      • Infrastructure
      • Lake Mead
      • Lake Powell
      • Oroville Dam
      • San Luis Dam
      • Shasta Dam
      • State Water Project
    • Environmental Issues
      • Anadromous Fish Restoration
      • Ecosystem
      • Endangered Species Act
      • Invasive species
      • Lake Tahoe
      • Mono Lake
      • Public Trust Doctrine
      • Salmon
      • San Joaquin River Restoration
      • Watershed
      • Wetlands
    • Leaders and Experts
    • Regions
      • Central Coast
      • Central Valley
      • Mexico
      • Nevada
      • North Coast
      • Pyramid Lake
      • Sacramento Valley
      • Salton Sea
      • San Joaquin Valley
      • Sierra Nevada
      • Southern California
      • Tulare Lake Basin
    • Rivers
      • Carson River
      • Colorado River
      • Klamath River
      • New River
      • North Coast Rivers
      • Russian River
      • Sacramento River
      • Truckee River
      • San Joaquin River
    • Water Issues
      • Climate Change
      • Coronavirus
      • Drought
      • Earthquakes
      • Energy and Water
      • Floods
      • Fracking
      • Growth
      • Hydropower
      • Levees
      • Tribal Water Issues
      • Water Conservation
    • Water Quality
      • Drinking Water
      • Nitrate contamination
      • Pollution
      • Stormwater
      • Wastewater
      • Water Quality
    • Water Supply and Management
      • Acre Foot
      • Aquifers
      • California Water Plan
      • Conjunctive Use
      • Desalination
      • Grey water
      • Groundwater
      • Integrated Regional Water Management
      • Recreation
      • Surface Water
      • Water Marketing and Banking
      • Water Rates
      • Water Recycling
      • Water Supply
      • Water Transfers
  • Tours & Events
    • Water Tours
      • 2024 Tour Sponsors
    • Events
    • Event Calendar
    • Past Tours & Events
      • Anne J. Schneider Fund Lecture Series
  • Specialized Programs
    • Water Leaders
      • Cohort Rosters
      • Yearly Class Reports
      • Your Alumni Network
      • Alumni Profiles
    • Project WET
      • Workshops
      • Special Workshops & Events
      • Supplementary Materials
      • California Content Standard Correlations
      • Facilitator's Trainings
      • Foundation School Programs
        • Elementary Programs
        • Secondary Programs
      • Water Kids
      • California Project WET Gazette
      • Gazette Archives
    • Colorado River Project
    • GRA Scholastic Fund Program
  • Maps & Guides
    • Maps & Posters
    • Layperson's Guides
    • Map & Guide Bundles
    • Books
    • Colorado River Materials
    • California Runoff Rundown
    • Other Publications
    • Water Awareness Materials
    • Downloadable Publications
    • Videos and DVDs
      • Video Clips
    • School Age Publications
    • Stickers
    • Free Programs and Publications
  • Newsroom
    • Western Water News
    • Aquafornia
      • About Aquafornia
    • Information Desk
    • Western Water Magazine Archive
      • Full Print Edition
      • Print Edition Excerpts
    • River Report Archive
  • Aquapedia
    • Alphabetical List of Subjects
      • A
      • B
      • C
      • D
      • E
      • F
      • G
      • H
      • I
      • J
      • K
      • L
      • M
      • N
      • O
      • P
      • Q
      • R
      • S
      • T
      • U
      • V
      • W
      • X
      • Y
      • Z
    • Historical Water People
    • Where Does My Water Come From?
      • Northern California
      • Sacramento
      • North Bay
      • South Bay
      • Central Valley
      • Los Angeles
      • Inland Empire
      • San Diego
      • All California Water Sources
    • Timelines
    • Videos
    • Image Gallery
    • Water Directory
      • Federal Agencies
      • State Agencies in California
      • Environmental Organizations
      • Other California Organizations
      • State and Federal Legislative Committees
      • Water Associations and Groups
      • Western States Water Agencies and Districts
    • Online Resources
    • Useful Acronyms
    • About Aquapedia
  • About
    • About Us
      • Board of Directors
      • Staff Biographies
      • Job Openings
    • Announcements
    • Support Our Mission
      • Become a Member
      • Donate in Honor/Memory
      • Planned Giving
    • Contact Us
Aquapedia background February 11, 2014 Sacramento-San Joaquin Delta Map Layperson's Guide to the Delta

Suisun Marsh

Suisun MarshSuisun Marsh is where fresh water from the Sacramento-San Joaquin Delta mixes with salt water from San Francisco Bay. The 116,000-acre marsh is the largest contiguous brackish-water wetland in California and perhaps the entire western coast of North America, providing food and habitat for thousands of migratory birds on the Pacific Flyway and many species of plants, fish and wildlife.

Biodiversity

It is a complex of tidal wetlands, diked seasonal wetlands, sloughs and upland grassland that comprises more than 10 percent of the remaining wetlands in California.

The marsh is a center of significant biodiversity because of its continued protection and management as a wetland ecosystem. The state and private duck clubs manage most of the marsh, primarily for hunting and wildlife conservation.

The diversity is reflected in the wide array of plants and animals, especially native species, like the endangered salt marsh harvest mouse. Some species, such as the Suisun song sparrow and Suisun thistle are largely endemic to the marsh, as detailed in the book, Suisun Marsh, Ecological History and Possible Futures.

Salinity Control

Suisun MarshState Water Project and Central Valley Project exports from the south Delta reduce the Delta outflow to the ocean, which increases salinity. In the 1980s, project managers installed several salinity control gates in Suisun Marsh to protect wildlife habitat. 

These gates are opened when water flowing out of the Delta is fresh (generally in the winter) and are closed when the saltwater creeps back up the Bay in the summer.

Challenges

Since at least 2015, scientific fish surveys of the Delta and Suisun Marsh have shown an ongoing, sweeping population crash of native species.

Declines of some species, particularly Delta smelt, have triggered requirements under the U.S. Endangered Species Act to curtail pumping rates at the federal and state export facilities in the south Delta. Operators of the pumps must also restore 8,000 acres of tidal wetlands. 

Efforts to meet the restoration target, including a former duck club hunting grounds on the eastern edge of Grizzly Bay in Suisun Marsh that supports chinook salmon, longfin smelt and, historically, Delta smelt. Dikes and berms were removed to allow full daily tidal exchanges to resume. Completed in 2019, the 420-acre Tule Red Tidal Restoration Project is managed by the state Department of Fish and Wildlife with funding from the Department of Water Resources, operator of the state’s Delta pumping plant.

Updated May 2024

  • Print-friendly

Referring Pages

Share this page

  • Share on Facebook
  • Share on Twitter
  • Share on LinkedIn
  • Sent to a friend.
Print-friendly

Related Links

Aquapedia background February 11, 2014 Sacramento-San Joaquin Delta Map Layperson's Guide to the Delta
Delta Map for the Sacramento-San Joaquin Delta
Maps & Posters March 5, 2021 Layperson's Guide to the Delta Sacramento-San Joaquin Delta Education Bundle

Sacramento-San Joaquin Delta Map
Published March 2021

This beautifully illustrated 24×36-inch poster, suitable for framing and display in any office or classroom, highlights the Sacramento-San Joaquin River Delta, its place as a center of farming, its importance as an ecological resource and its vital role in California’s water supply system. 

The text, photos and graphics explain issues related to land subsidence, levees and flooding, urbanization, farming, fish and wildlife protection. An inset map illustrates the tidal action that increases the salinity of the Delta’s waterways. 

  • Read more
Publication April 17, 2014 Sacramento-San Joaquin Delta Map

Layperson’s Guide to the Delta
Updated 2020

The 24-page Layperson’s Guide to the Delta explores the competing uses and demands on California’s Sacramento-San Joaquin Delta. Included in the guide are sections on the history of the Delta, its role in the state’s water system, and its many complex issues with sections on water quality, levees, salinity and agricultural drainage, fish and wildlife, and water distribution.

  • Read more
Back
This item appears in:
  • Topic: Suisun Marsh
  • S
Footer pod May 20, 2014

Water Education Foundation

Copyright © 2025 Water Education Foundation. All rights reserved.

The Water Education Foundation is a nonprofit, tax-exempt, 501(c)3 organization, federal tax ID #942419885.

Privacy Policy

Donor Privacy Policy

  • Read more
Footer pod May 20, 2014

Contact Information

2151 River Plaza Drive, Suite 205
Sacramento CA 95833

Telephone (916) 444-6240

Contact Us via email

  • Read more

Quicklinks

Footer quicklink May 20, 2014

Contact Us

  • Read more
Footer quicklink May 20, 2014

Donate Today

  • Read more
Footer quicklink May 20, 2014

Tours

  • Read more
Footer quicklink May 20, 2014

Newsletter Signup

  • Read more
Footer quicklink May 20, 2014

Foundation News

  • Read more
Footer quicklink May 20, 2014

Calendar

  • Read more

Log in

  • Create new account
  • Request new password

Commands

  • Support portal
  • Log in