History of the Interagency Ecological Program

The Interagency Ecological Program (IEP) was formed over 50 years ago with the goal of providing sound scientific information to water managers, the public, and the scientific community in the San Francisco Estuary. Over the years, IEP has had to adapt to a wide array of social, political, and environmental changes. With the Estuary continuing to be a hub of water movement, IEP will continue to strive to provide the most reliable data and sound science to inform the management of our unique ecosystem.

Historical Perspective of the IEP

In 2012, with the IEP approaching  its 50 year mark, Perry Herrgesell drafted a report describing the historical development of the IEP, its strengths, and weaknesses.

A Historical Perspective of the Interagency Ecological Program (2012) (PDF)
by Perry Herrgesell

IEP 1970-2020

IEP Timeline


Original "Memorandum of Understanding between Departments of Water Resources and Fish and Game Regarding Objectives and Scope of Delta Water Project Fish and Wildlife Study" signed, which developed the "Interagency Ecological Study Program (IESP)".


Memorandum of Agreement (MOA) signed by the State of California Department of Water Resources (DWR), the California Department of Fish and Game (DFG), the United States Bureau of Reclamation (USBR), and the United State Bureau of Sport Fisheries and Wildlife (USBSFW) (now known as the U.S. Fish and Wildlife Service).
The MOA was to "... provide for the performance of studies necessary to obtain a thorough understanding of the requirements of fish and wildlife resources.


An amendment to the 1970 memo was signed by the four existing signatory parties (DWR, DFG, USBR, USFWS) and included two new agencies - the State Water Resources Control Board (SWRCB) and the United States Geological Survey (USGS).

The amendment was to implement Hydrodynamic, Physical and Chemical studies, utilize funds and resources in an efficient manner, define Coordinators, and define the work that each agency would do.


An amendment to the 1970 memo was signed by the existing six agencies (DWR, DFG, SWRCB, USBR, USFWS, USGS) and included one new agency -the United States Army Corps of Engineers (USACE).

The amendment extended the terms of the MOU to 09/30/2000, broadened the objective while specifically noting the State and Federal Projects.


An amendment to the 1970 memo was approved to add the United States Environmental Protection Agency as a signatory party. This made 8 signatory parties to the MOU.


An MOU was signed between the Aquatic Habitat Institute (now known as the San Francisco Estuary Institute) and the IESP to maximize information sharing and coordination through the implementation of the Regional Monitoring Strategy.


The amendment to the 1970 memo titled "2000 MOU" abbreviated the name of the IESP to "IEP", extended the terms of the agreement to 09/30/2010 and added recognition of California protected species (CA take) and Quality Assurance/Quality Control measures.

This amendment was signed by nine agencies - CA DWR, CA DFG, SWRCB, USBR, USFWS, USGS, USEPA, USACE, and the National Marine Fisheries (NMFS).


An amendment to the agreement extended the term to 09/30/2012 and added language "or until terminated as provided herein."

2012, 2014

Amendments to the MOU to extend the term dates to 09/30/2014 and 05/31/2016, respectively.


An amendment to the MOU (PDF) extended the term language to read as "shall remain in effect until terminated" and added terms for termination.