Salton Sea

Salton Sea
The Salton Sea is one of the most important places for birds in North America and is in danger of disappearing. If it does, we will lose a vital part of the Pacific Flyway and face a toxic dust bowl that will threaten public health for more than a million Californians.

Audubon California has an opportunity to help solve some of the immense challenges of the Salton Sea by providing:

  • Comprehensive bird data collection
  • Detailed habitat mapping
  • Public education
  • Policy advocacy

Birds of the Salton Sea

The Salton Sea covers 350 square miles across Riverside and Imperial counties. As part of the Colorado River Delta, the sea filled and dried for thousands of years prior to its current incarnation, which came into existence as the result of a massive flood of the Colorado River in 1905.

More than 400 species of birds make regular use of the Salton Sea, and it has been designated an Audubon Important Bird Area of Global Significance:

  • Vital for waterfowl on the Pacific Flyway, hosting 50% of the Pacific Flyway population of Ruddy Duck and other species including Cinnamon Teal and Northern Shoveler.
  • Largest interior wintering population of Western Grebes and 90% of the overwintering population of Eared Grebes.
  • Home to 40% of the global population of the Federally Endangered Yuma Ridgway’s Rail.
  • Primary wintering area in the interior U.S. for California Brown Pelican and the American White Pelican.
  • Provides vital habitat for shorebirds, including the interior population of Snowy Plovers, Black-necked Stilts, Least Sandpipers, Western Sandpipers, and American Avocets.
  • Hosts up 25% of the breeding Caspian Terns in North America, which may be important given attempts to reduce the Caspian Tern population in Washington.

Click here to explore the Important Bird Area site profile. eBird observations can also be viewed here.

As the Salton Sea dries, salinity and selenium increase, depleting food resources and posing health risks to birds. There have been several major die-offs of birds there, with major recent events including 150,000 Eared Grebes in 1992, 9,000 White Pelicans in 1996, and more than 11,000 waterbirds in 1998. BirdLife International has named the Salton Sea an “IBA in Danger,” a designation reserved for habitat areas at severe risk.

salton sea crop
Crisis looming

The sea as we know it may soon be gone. For years, irrigation run-off water in the Imperial Valley fed the sea. But in 2003, a deal was struck to divert more than 400,000 acre-feet of water that once flowed to the Salton Sea to San Diego and Coachella for urban uses. In 2018, water provided to the Salton Sea as mitigation for the 2003 deal will be shut off, meaning the sea will shrink even further..

In the next 15 years, the Salton Sea will lose 40% of the water currently flowing into it. It will drop by twenty feet and expose 100 square miles of dust-generating lake bottom. The region’s strong winds will create contaminated dust clouds, worsening the already poor air quality in the region. Salinity in the lake will triple, eliminating its fishery and most invertebrates that provide value to birds.

Although the State of California in 2003 agreed to provide for habitat restoration and dust mitigation, the state has yet to follow through on these promises, and the situation at Salton Sea continues to worsen as the 2018 deadline looms with no solution.

The human population of the air basin around the lake is now at about 650,000, and it will be double that in 15 years. This population is mostly Latino and low-income, and currently suffers high rates of asthma and other chronic health conditions tied to dust.

Audubon’s role

  • Comprehensive bird data collection. Because the Salton Sea is rapidly changing, older bird surveys and data are out-of-date, and yet there aren’t any comprehensive initiatives to update this information. Using its citizen science network of chapters and volunteers, Audubon will fill this gap.
  • Detailed mapping. Any comprehensive plan to restore the Salton Sea will require comprehensive GIS mapping of its conservation values for birds and habitat. Working with Audubon, ESRI will build on the work it has already done in this area.
  • Public education. Using the power of its network, Audubon will work with environmental and public health NGOs in the region to raise awareness about the issues at the Salton Sea.
  • Policy advocacy. With its partners in the State Legislature, Audubon will build on its history of policy successes in Sacramento by helping craft a legislative solution to encourage the State of California keep its promise to the people of Riverside and Imperial counties, while also preserving a vital place for birds of the Pacific Flyway.

Graphic shows satellite tagged Caspian Terns from many locations along Pacific Flyway all arriving at the Salton Sea

Burrowing Owls in Imperial Valley

Just south of the Salton Sea lies the Imperial Valley, home to about 70% of the state's breeding Burrowing Owls, or about 4,000 breeding pairs. The population of this small bird has been in sharp decline over the last 50 years. No one factor has been implicated in its decline, but the cumulative impacts of human activities have certainly contributed. Farming and renewable energy development both pose risks to this bird's habitat in the Imperial Valley.

Audubon California, with the support of the Imperial Valley Community Foundation, has created a publicly available, interactive map that consolidates Burrowing Owl survey data from the past decade in Imperial Valley. The map includes supporting layers such as renewable energy projects, crop types, irrigation canals and drains, and more. We encourage you to explore the map and learn more about this region, so critical to Burrowing Owls in California.

Maps such as these have allowed researchers to learn about Burrowing Owls in the Imperial Valley. This information can be used to help prioritize future conservation areas, and to identify information gaps and areas not yet surveyed. Here are a few fun facts, revealed by scientists studying survey data collected by the Imperial Irrigation District (IID):

  • Burrowing Owl abundance is best predicted (from among many environmental variables) by the number of available burrows and the presence of alfalfa. Alfalfa happens to be the one of the most common crops in the Imperial Valley.
  • Burrowing Owls nest almost exclusively within or along irrigation drains, canals, and ditches, particularly earthen drains.

A larger version of the map is available here. A 2015 report by Audubon California, available here, details the methodology, documents data sources, identifies potential conservation lands, and proposes lands that may be particularly suitable for alternative land uses like renewable energy projects. 

If you have Burrowing Owl survey data for the Imperial Valley that you'd like to share, please email

Note: GIS users who wish to access the underlying data may do so by following the steps below:

  1. Open the Layer List (the 2nd button on the left side panel).
  2. Find the layer of interest and select the drop-down arrow to the right of its name.
  3. Select "Show Item Details" from the drop-down menu. This will open a new page that includes metadata for the layer of interest, and any related layers.
  4. On this new page, you can click the Open button, which brings up a drop-down menu. In this menu, select "Open in ArcGIS for Desktop". This downloads a file that you can open in ArcMap.
  5. In ArcMap, you are still accessing the online layer. If you'd like to save your own copy, you can right click on the layer in the Table of Contents and select Data > Export.

Click here for downloadable fact sheet

Copyright  2015 National Audubon Society, Inc