Department of Water Resources Home
Cliff Feldheim, Chief
Environmental Planning and Information Branch
Suisun Marsh Program
3500 Industrial Blvd.
West Sacramento, CA 95691
(916) 376-9693
Mailing Address:
P.O. Box 942836
Sacramento, CA 94236-0001
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Suisun Marsh Program

Since the early 1970's, the California Legislature, the State Water Resources Control Board (SWRCB), US Bureau of Reclamation (USBR), California Department of Fish and Game, (DFG), Suisun Resource Conservation District (SRCD), California Department of Water Resources (DWR), and other agencies have focused on preserving the Suisun Marsh as a unique environmental resource  and ecologically important component of the San Francisco Bay Estuary (Estuary).

1970: 4-Agency Memorandum of Agreement

In 1970, a 4-Agency MOA was entered into between the DFG, DWR, USBR, and the US Fish and Wildlife Service (FWS).  The intent was to provide for studies necessary to obtain a thorough understanding of the requirements of fish and wildlife resources in the Estuary.  A study specifically related to the Suisun Marsh was identified to evaluate alternative means of providing substitute freshwater supplies that would enable habitat protection and enhancement for wintering and breeding waterfowl using the Suisun Marsh.

1974: The Nejedly-Bagley-Z'Berg Suisun Marsh Protection Act

In 1974, The California Legislature enacted the Suisun Marsh Preservation Act which protected the Marsh from urban development.  The Act required the San Francisco Bay Conservation and Development Commission (BCDC) to develop a plan for the Marsh and develop guidelines (i.e., restrictions) for development within Marsh boundaries.

1976: Suisun Marsh Protection Plan

This Suisun Marsh Protection Plan was developed by BCDC in 1976, and defines and limits development within primary and secondary management areas for the "future of the wildlife values of the area as threatened by potential residential, commercial, and industrial development".   The focus of the Plan is on maintaining habitat for waterfowl. 

1977: AB 1717, the Suisun Marsh Protection Act of 1977

AB 1717, adopted in 1977, calls for the implementation of the Suisun Marsh Protection Plan.  AB 1717 designates the BCDC as the State agency with regulatory jurisdiction of the Marsh and calls for the Suisun Resource Conservation District (SRCD) to have responsibility for water management in the Marsh.  The law focuses on actions for the preservation of waterfowl in the Suisun Marsh along with a diversity of wildlife through the:

  • Establishment and maintenance of adequate water quality;

  • Improvement of present water management practices;

  • Establishment of a water quality criteria that allows for the production of plants that serve as important food for waterfowl using the Suisun Marsh;

  • Provision for supplemental water supplies and facilities to maintain adequate water quality.
The Act states that land within the Suisun Marsh should be acquired for public use or resource management if it is suitable for restoration to tidal or managed marsh but that such restoration cannot be required as a condition of private development.

1978: SWRCB Water Rights Decision 1485

In 1978, the SWRCB adopted the Water Quality Control Plan for the Sacramento San Joaquin Delta and issued Water Rights Decision 1485. The Decision includes: channel water salinity standards from October to May and preserves the area as brackish tidal marsh. It also set water quality standards in the Suisun Marsh as a condition of export pumping by DWR and USBR.  These standards were based on the need to provide high quality food for breeding and wintering waterfowl in the Suisun Marsh.  The standards were based primarily on ecological studies conducted by Mall (1969) and Rollins (1973). These two studies examined: 1) the relative value of marsh plants as duck food; 2) the influence of soil salinity and other factors on distribution and growth of marsh plants; and 3) the relationships between channel water salinity and soil salinity.  It was concluded that improved management practices, improved drainage, water control facilities, and adequate water quality were needed to achieve desired soil salinity conditions to maintain high quality food for breeding and wintering waterfowl.

Development of the Initial Facilities

As a result of the need to provide better managed wetland (i.e. duck hunting club) management, and manage salinity levels in the Marsh, DWR and USBR constructed and continue to operate facilities in the Marsh that provide flood up and drainage for managed wetlands in the Marsh, and help manage salinity.

1979-80: Roaring River Distribution System

The Roaring River facility is located near the eastern end of Montezuma Slough and provides seasonal water management needs to approximately 5,000 acres of managed wetlands on Simmons, Hammond, Van Sickle, Wheeler, and Grizzly islands by providing lower salinity water from Montezuma Slough. It is designed to tidally pump water from Montezuma slough through a bank of eight 60-inch culverts equipped with fish screens that are maintained and operated by DWR.

1979-80: Morrow Island Distribution System (MIDS)

The Morrow Island Distribution System in the western marsh diverts water from Goodyear Slough to the eastern most area of Morrow Island.  The System allows wetland managers to use lower salinity water from Goodyear Slough then drain into Grizzly Bay.

1979-80: Goodyear Slough Outfall

This facility connects the south end of Goodyear Slough to Suisun Bay eliminating the original dead-end nature of the Slough.  The facility increases circulation while reducing salinity in Goodyear Slough.

white pelicans
Photo by Florence Low

1984: Plan of Protection for the Suisun Marsh

In 1984, DWR and the USBR developed and began implementing the Plan of Protection (POP) in accordance with D-1485. The POP implementation strategy was to construct large facilities and distribution systems to meet salinity standards (lower channel water salinity), in lieu of significant Central Valley Project/State Water Project storage releases estimated as high as 2 million acre-feet in dry/critical water years. The six-phase POP was the programmatic blue print (required by the SWRCB and embodied in the Suisun Marsh Preservation Agreement). Two of the six phases were completed including the Initial Facilities and the Suisun Marsh Salinity Control Gates.

1987: Suisun Marsh Preservation Agreement (SMPA)

The SMPA is a contractual agreement between DWR, USBR, DFG and SRCD which contains provision for DWR and USBR to mitigate the effects on Suisun Marsh channel water salinity from State Water Project and Central Valley Project operations and other upstream diversions. The SMPA requires DWR and USBR to meet salinity standards, sets a timeline for implementing the Plan of Protection, and delineates monitoring and mitigation requirements. The Suisun Marsh Monitoring Agreement and the Suisun Marsh Mitigation Agreement were also signed at this time. The Suisun Marsh Mitigation Agreement defined habitat requirements to mitigate effects of facilities and operations and the Suisun Marsh Monitoring Agreement defines requirements for monitoring salinity and outlines criteria for the conservation and monitoring of the Salt Marsh Harvest Mouse, and other native wildlife in the Marsh.

1988: Suisun Marsh Salinity Control Gates

Suisun Marsh Salinity Control Gates were completed and became operational in October of 1988. The first year of operation was used to test the gates, and official operation began in November 1989. Montezuma Slough, one of the largest slough, is open at both ends, and its flood tide current is longer and stronger than its ebb tide current, causing a net west-to-east flow which draws higher saline water eastward from Grizzly Bay.  The gates span Montezuma Slough near the Roaring River intake and are periodically operated from September to May.  The Gates block the salty flood tide from Grizzly Bay but allow passage of the freshwater ebb tide from the mouth of the Sacramento-San Joaquin Delta proving higher quality water to the nearby managed wetlands.

1991: Cygnus and Lower Joyce Facilities

Cygnus and Lower Joyce, original SMPA facilities, were completed in 1991 and allow for more rapid filling and draining of managed wetlands (i.e., duck hunting clubs). In addition, there are numerous small facilities that exist in the Suisun Marsh, which were installed or replaced under the DWR and USBR individual cost-share program.

1994: Bay-Delta Accord

On December 15, 1994, state and federal agencies, working with agricultural, environmental, and urban stakeholders, reached agreement on water quality standards and related provisions that would remain in effect for three years. This agreement, known as the Bay-Delta Accord, was based on a proposal developed by the stakeholders. Elements of the agreement include:

  • Springtime export limits expressed as a percentage of Delta inflow;

  • Regulation of the salinity gradient in the estuary so that a salt concentration of two parts per thousand (X2) is positioned where it may be more beneficial to aquatic life;

  • Specified springtime flows on the lower San Joaquin River to benefit Chinook salmon;

  • Intermittent closure of the Delta Cross Channel gates to reduce entrainment of fish into the Delta.
1995 - 1998: SWRCB Water Quality Control Plan

In 1994, wildlife and fishery agencies and urban water users expressed concerns about the appropriateness of western Suisun Marsh channel water salinity standards. The SWRCB, in the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary, May 1995, modified the Suisun Marsh salinity objectives. Modeling analysis by the Suisun Marsh Planning Program showed that Suisun Marsh standards would be met most of the time at all Suisun Marsh compliance stations. Some standard exceedances would be expected in the Western Marsh that participants to the SMPA agreed could be mitigated by more active water control by landowners.

1995: Suisun Ecological Workgroup

The 1995 Water Quality Control Plan recommended that the Department of Water Resources (DWR) convene a multi-agency ecological workgroup to evaluate the beneficial uses and water quality objectives in the Marsh. The SWRCB asked for specific measures to implement the narrative objectives in the 1995 WQCP.

1995: Amendment Three to the SMPA

The purpose of Amendment Three was to provide equivalent protection to Suisun Marsh managed wetlands as intended under the original SMPA, while recognizing the effects of increased Delta outflow and effective operation of the SMSCG. Amendment Three changed DWR/USBR's focus in the Marsh towards improving management capabilities of the landowners instead of the construction of large-scale facilities.

1998: Ecological Coordination Advisory Team

The Ecological Coordination Advisory Team was convened to ensure compliance with conditions, mitigation, and monitoring responsibilities specified in the Suisun Marsh Preservation Agreement. ECAT includes staff from the US Bureau of Reclamation, DFG Grizzly Island, DFG Central Valley Bay-Delta Branch, Suisun Resource Conservation District, and Department of Water Resources. The US Fish and Wildlife Service, NOAA Fisheries, and US Army Corps of Engineers staff have participated in and advisory role.

1999: SWRCB Water Rights Decision 1641

The SWRCB issued Decision 1641 in December 1999, which updated salinity standards for Suisun Marsh. Increased outflow and salinity requirements for the Bay-Delta provided indirect benefits to the Suisun Marsh. DWR proposed that the SWRCB adopt the Amendment Three actions for Suisun Marsh in this Decision. The SWRCB was unable to adopt Amendment Three actions because the Section 7 consultation with the USFWS had not concluded. However, the SWRCB did relieve USBR and DWR of its responsibility in meeting salinity objectives at the S-35 and S-97 water quality stations in the western Marsh.

coot shoveler teal
Photo by Florence Low

2000: CALFED Suisun Marsh Charter

The goal of the Suisun Marsh Charter is to develop a regional plan that balances implementation of the CALFED Program, SMPA, and other management and restoration programs within Suisun Marsh in a manner responsive to the concerns of stakeholders and based upon voluntary participation by private landowners.

2001: Suisun Marsh Charter Implementation Plan

The Suisun Marsh Charter was completed in 2001 and commenced development of an Implementation Plan. Charter participants collaborated on a joint presentation to the State of the Estuary Conference on the principles of the Charter Plan including coordinated water quality, endangered species, and waterfowl hunting heritage value protection in the Suisun Marsh.

2001: CALFED Grant Proposal

Suisun Marsh Property Acquisition and Habitat Restoration is a proposal to acquire a seasonally managed parcel in the Suisun Marsh that fit selected criteria, conduct pre-project monitoring, and restoration planning. In addition, it is a pilot project to implement findings of the CALFED Suisun Marsh Levee Investigation Team. This project was funded by CALFED for $536,750 with matching funds being provided by the SMPA funds.

2003: Habitat Management, Preservation, and Restoration Plan

The expansion of the Charter process to include additional federal and state agencies to develop a Suisun Marsh Plan that will balance the goals and objectives of the Bay-Delta Program, Suisun Marsh Preservation Agreement (SMPA), and other management and restoration programs within the Suisun Marsh in a manner that is responsive to the concerns of all stakeholders and is based upon voluntary participation by private landowners.

2014: Suisun Marsh Habitat Management, Preservation, and Restoration Plan EIR/EIS Record of Decision Signed (Suisun Marsh Plan).

The Suisun Marsh Plan provides the basic permitting framework for 5,000 to 7,000 acres of tidal restoration within the Suisun Marsh to benefit native fish.  Tidal restoration in the Marsh has a potentially negative significant impact on waterfowl.  The SMP mitigates that impact by providing for the enhancement of 40,000 to 50,000 acres of managed wetlands to benefit breeding and winter waterfowl in the Suisun Marsh. 

2014: Suisun Marsh Waterfowl & Managed Wetland Program

The Suisun Marsh is a unique estuarine system providing important habitat for a variety of waterfowl and other waterbirds.  Gaining a better understanding of that importance and finding ways to maintain and increase the value of the Suisun Marsh for waterfowl and other waterbirds into the future is the focus of a long-term research program... click here for more information

wetland sunrise
Photo By Cliff Feldheim