Salton Sea

The Salton Sea is a shallow, landlocked, and highly saline endorheic lake.

An endorheic lake is a body of water that has no outlet to the sea. This lake sits within Riverside and Imperial counties in Southern California. It is located on the San Andreas Fault inside the Salton Trough. This trough stretches toward the Gulf of California in Mexico.

A 2023 report measured its surface area at 318 square miles. The lake is a unique feature in a desert landscape.

To understand the lake, one must look at the history of the Colorado River. Over millions of years, the river's delta expanded and cut off the northern Gulf of California. The river has historically alternated between filling the basin and leaving it dry. When the river flowed into the basin, it created a freshwater lake. One such lake was Lake Cahuilla, also known as the Blake Sea. This ancient lake was six times larger than the modern Salton Sea.

Archaeological sites show Native Americans lived near these shores for thousands of years.

The modern Salton Sea formed due to a massive engineering accident in 1905.

In 1900, the California Development Company began digging irrigation canals. These canals were meant to bring Colorado River water to the Imperial Valley. In 1905, heavy rain and snowmelt caused the river to swell. This flood broke through a canal head-gate. The water diverted into the dry Salton Basin through the New and Alamo rivers. For two years, the river flowed into the basin until the breach was closed in 1907.

During the early 20th century, the lake remained full due to agricultural runoff. Farmers used large amounts of Colorado River water for irrigation. Much of this excess water flowed back into the lake. By the 1950s and 1960s, the area became a popular resort destination.

Communities grew with hotels, yacht clubs, and vacation homes. At its peak, more than 1.5 million people visited the area annually. The wetlands also became a vital stop on the Pacific Flyway for migratory birds.

However, the lake began to face a catastrophic decline in the late 20th century. Scientists warned in the 1970s that the lake would become inhospitable. The lake is fed by runoff from about 500,000 acres of farmland. This runoff contains salts, selenium, and fertilizers like nitrates. As the water evaporates in the desert heat, the salt concentration increases.

This high salinity caused massive die-offs of fish species. When the fish died, the bird populations that relied on them also declined.

In recent decades, the lake has faced new environmental challenges. After 1999, the lake began to shrink as farmers used water more efficiently. As the water recedes, it exposes the lake bed. The wind then carries clouds of toxic dust into nearby communities.

This dust contains salts and other materials from the dried bed. Local, state, and federal efforts to manage the dust have seen minimal success. The situation remains a serious concern for air quality in the region.

Efforts are currently underway to restore parts of this ecosystem. In 2017, the state developed the Salton Sea Management Program. The Torres Martinez Desert Cahuilla Indians partnered with the state to restore wetlands in 2018.

In 2021, construction began on the Species Conservation Habitat project. This project focuses on the delta of the New River. In 2025, water began flowing into the first complex of shallow ponds. These projects aim to manage dust and support wildlife in a changing environment.