Smelt Working Group

The Smelt Working Group (SWG) consists of experts in delta smelt biology from the U.S. Fish and Wildlife Service, U.S. Bureau of Reclamation, U.S. Environmental Protection Agency, California Department of Water Resources, National Oceanic and Atmospheric Administration (NOAA) Fisheries Service and California Department of Fish and Wildlife.

The SWG evaluates up-to-date biological and technical issues regarding delta and longfin smelt and develops recommendations for consideration by the Service in its implementation of the Long-Term Operation of the Central Valley Project and State Water Project ("OCAP").

Enhanced Monitoring

Delta smelt data, Steve Martarano USFWS

Technician Brynn Pearles records data from
daily tows on the Delta in March 2017.
Credit: Steve Martarano, USFWS

Featured Story
April 18, 2017
Wanted: More smelt data. Enhanced Delta Smelt Monitoring Program helps fill the void

The Lodi Fish & Wildlife Office Delta Juvenile Fish Monitoring Program conducts daily Enhanced Delta Smelt Monitoring during critical parts of the year. This provided the Service, and state and federal water managers valuable near real-time information about the location of Delta smelt.

California WaterFix

AKA "Delta Tunnels." Visit our California WaterFix page.

Water Projects Briefing

On Jan. 23-24, 2014 our office gave a briefing (PDF) to media and congressional staff on the delta smelt biological opinion on Delta water projects.

Delta Smelt, Peter Johnson USFWS
Delta Smelt, Peter Johnson USFWS (More species photos)

Longfin Smelt, René Reyes, USBR
Longfin Smelt Juvenile, René Reyes, USBR

Smelt Working Group Meets to Help Delta Smelt Survive

Field Notes, February 28, 2012

It's a Monday morning in late January. A good three months behind schedule, the first significant rainfall of the 2011-12 water-year has hit the Sacramento/San Joaquin Bay-Delta region over the weekend. It's time for the Smelt Working Group to spring into action. Story


The Delta Smelt Risk Assessment Matrix is designed to protect delta smelt at Federal and State Delta export facilities. It consists of month by month criteria which, when exceeded will trigger a meeting of the Smelt Working Group. Read the full technical explanation (PDF).