Interagency Ecological Program (IEP)


Our research vessel, Sentinel, sails on the San Joaquin River near the Antioch bridge. DWR/2016

The Interagency Ecological Program (IEP) is a consortium of State and federal agencies that has been conducting cooperative ecological investigations since the 1970s. They provide and integrate relevant and timely ecological information for management of the Bay-Delta ecosystem and the water that flows through it. IEP believes the highest quality science contributes to achieving a reliable and sustainable water supply and a healthy Bay-Delta ecosystem.


IEP relies upon multidisciplinary teams of agency, academic, nongovernmental organizations, and other scientists to conduct collaborative and scientifically sound monitoring, research, modeling, and synthesis efforts for various aspects of the aquatic ecosystem. IEP also holds an annual workshop, publishes a quarterly newsletter and science highlights, and conducts technical and programmatic reviews of the program and its elements.


For more information about how IEP has evolved and is guided, the following documents are available on request:

  • IEP Guiding Principles 
  • IEP Strategic Plan 
  • IEP Governance Framework
  • IEP 2019 Annual Work Plan
  • IEP 2019 Data Management Plans
  • IEP Science Strategy 2020
  • IEP Science Strategy 2020 Executive Summary
  • IEP Lead Scientist
  • A Historical Perspective of the Interagency Ecological Program


IEP’s science is accomplished through collaborative and scientifically sound monitoring, research, and synthesis efforts for various aspects of the aquatic ecosystem in the San Francisco Estuary. Its Science Strategy integrates science needs and management challenges, and serves as a subject-matter guide for focused scientific studies. The IEP Annual Work Plan is a summary of the work member agencies plan to conduct as part of its consortium within the Bay-Delta ecosystem.  Additional collaborative science opportunities are available through IEP project work teams, which are a public forum for scientific coordination, collaboration, discussion, and review of specific topic areas of importance to the IEP and the greater scientific community.


Synthesis is the integration of multiple lines of evidence and information into a single, cohesive story on a topic. With vast amounts of data collected every day in the Bay-Delta and extensive research all published separately, IEP emphasizes the need for synthesis efforts to provide information that is useful for management. IEP synthesis teams analyze diverse datasets from monitoring and research to provide complete and cohesive information relevant to specific management questions. Scientists from many IEP agencies work collaboratively to provide timely information for Bay-Delta management through current and previous synthesis projects. Synthesis products include technical reports, peer-reviewed publications, science highlights, and conference presentations.  The Guiding Framework for IEP Synthesis explains in detail the goals and processes for planning and conducting synthesis work within IEP.


IEP seeks to collaboratively produce and communicate the highest quality science needed for achieving a reliable and sustainable water supply for the people of California and a healthy Bay‐Delta ecosystem. IEP reaches out to the broader community through the IEP Annual Workshop, recruitment, stakeholder outreach and engagement, and regular online announcements about IEP efforts. IEP uses independent programmatic reviews (IEP Science Advisory Group) as an indicator of programmatic success and to ensure long-term relevancy and viability of the program. In support of these objectives, the planned Delta Research Station would provide improved and additional facilities for IEP and continued engagement with other agency and stakeholder programs.

IEP consists of nine member agencies: three State departments and six federal. IEP also has several key partners. You can view the latest 2016 Memorandum of Understanding (MOU) for information about these relationships. The 1970 MOU was amended in 1985, 1990, 1992, 2000, 2010, 2012, 2014, and 2016.

Member Agencies


The IEP Stakeholder Group consists of IEP agency representatives and stakeholders who participate outside the Science Management and Coordinators Teams but use information and data developed by IEP for the management and regulation of water quality and biological resources of the San Francisco Estuary.        

The Stakeholder Group meets quarterly to hear about current IEP monitoring and research activities and to discuss priorities for future monitoring, research, and other issues of interest or concern to stakeholders. Stakeholder meetings also provide an opportunity for exchanging information and improving collaboration within the Delta science community.

IEP completed a Stakeholder Engagement Plan (PDF) in 2013, followed by an expanded Communication and Engagement Plan (PDF) in 2015. The purpose of these plans is to guide IEP internal and external communications and efforts to involve stakeholders as valued partners. The Communication and Engagement Plan clearly defines the IEP’s approach to stakeholder engagement and the avenues and timing by which communication will be accomplished among the IEP agencies as well as externally.

IEP stakeholders are interested entities who may affect, be affected by, or perceive themselves to be affected by, a decision, activity or outcome of IEP. As such, IEP’s stakeholders generally include:

  • Projects and programs of agencies not otherwise represented at IEP Agency management or coordination meetings
  • Other local, State, and federal agencies who are not members of IEP
  • Nongovernmental organizations
  • Water contractors
  • Academia, researchers, and scientists
  • Business owners, land owners, farmers, recreational and commercial fisheries, and ranchers
  • Members of the public

Much of IEP's science cooperation, collaboration, and coordination takes place in teams. The IEP Stakeholder Group and IEP project work teams (PWTs) are open to the public. PWTs focus on specific research and monitoring topics of interest. They are formed to:

  • Organize new studies
  • Review study plans and proposals
  • Write scientific papers and reports
  • Promote collaboration among different groups working on a topic of interest

New PWTs are proposed to the IEP Science Management Team and approved by the IEP Coordinators Team. PWTs are terminated when there is no longer a sufficient need or interest in the topic. View the Organization Structure (PDF), Organization Chart (PDF), and IEP Project Work Team Proposal Template (PDF) for more information.

Project Work Teams 

IEP conducts technical and programmatic reviews of the overall program and individual program elements to ensure continued relevance, scientific integrity and suitability, and compliance with legal requirements. These reviews are conducted by IEP staff with help from local and external experts. The IEP Science Advisory Group (SAG) is a standing panel of external experts that was established in the 1990s. IEP regularly calls on the SAG to review IEP elements and provide advice on scientific issues. In 2008, the CALFED Independent Science Board conducted an additional independent review of the IEP.

Newsletter and Subscriptions

The IEP Newsletter is a quarterly electronic publication that provides IEP program and science highlights as well as in-depth articles on important scientific topics for resource managers, scientists, and the public. Articles in the IEP newsletter are intended for rapid communication and do not undergo external peer review; all primary research results should be interpreted with caution. If you'd like to submit an article for publication, review our Guide to Authors (PDF).

To subscribe to the IEP newsletter, email your name, agency, and email address to

Archived Newsletters

IEP Status & Trends Report

Contact Information

Select the button below for Division of Environmental Services and IEP contact details.

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Technical Documents