Tulare Lake was once a massive body of water in California’s Central Valley, historically the largest freshwater lake by surface area west of the Mississippi River. Fed primarily by snowmelt runoff from the Sierra Nevada mountains, the lake’s basin was a closed, or endorheic, system that naturally collected water from four major rivers. At its peak, the lake could cover over 700 square miles, creating a uniquely rich ecosystem that sustained the Indigenous Yokuts people for thousands of years. The lake’s existence depended on the volume of winter snowpack and subsequent spring melt, which remained largely constant until the mid-19th century.
The Historic Timeline of Desiccation
The permanent disappearance of Tulare Lake was a progressive process that spanned over five decades. The lake’s decline began during the 1860s, coinciding with the influx of settlers following the California Gold Rush. These new arrivals quickly recognized the agricultural potential of the surrounding arid lands, which initiated the first significant diversions of water from the lake’s feeder rivers.
Before this period, the lake’s level fluctuated wildly, but it frequently overflowed its northern boundary into the San Joaquin River watershed. However, no overflow events were recorded after 1878 due to upstream water usage. The continuous and increasing diversion of the rivers for irrigation caused a rapid shrinkage, particularly during periods of drought.
The first recorded instance of the lake completely drying up occurred around 1890. Other accounts place the first full desiccation closer to 1899, with only residual wetlands remaining. This initial drying event was followed by periodic returns during high-water years in the early 1900s, but by the early 20th century, the lake had ceased to be a permanent fixture on the map.
The Mechanisms of Disappearance
Tulare Lake’s disappearance was caused by human intervention that altered the natural flow of its water sources. The lake was primarily fed by the Kings, Kaweah, Tule, and Kern rivers, which carried snowmelt from the Sierra Nevada. Settlers began diverting these rivers by building extensive networks of canals and ditches to irrigate the fertile surrounding plains.
This water redirection was driven by the rapid expansion of industrial agriculture in the San Joaquin Valley. Crops like cotton, alfalfa, tomatoes, and vast dairy operations demanded massive volumes of water for irrigation. By 1900, the Kings River alone was irrigating more land than all but two other rivers globally, demonstrating the scale of the water extraction.
The permanent control of the lake’s inflow was solidified through the construction of major dams and reservoirs on its tributary rivers in the mid-20th century. Dams such as Pine Flat on the Kings River, Terminus on the Kaweah, and Success on the Tule River were designed to capture and regulate the Sierra snowmelt, preventing the high-volume runoff that historically replenished the lake. These engineering projects effectively disconnected the lakebed from its natural sources of replenishment, converting the basin into one of the nation’s most productive agricultural regions.
Recurrence and Modern Status
Despite its historical desiccation, Tulare Lake is now considered an ephemeral lake, reappearing during exceptionally wet years. The lakebed is the lowest point in the southern Central Valley, and when dams on the feeder rivers reach capacity, excess floodwater naturally flows back into the depression. Notable re-emergences occurred in 1969, 1983, 1997, and most recently in 2023, following record-breaking snowpacks in the Sierra Nevada.
The current land use of the former lakebed is dominated by intensive agriculture, including cotton, nuts, and dairy farms. When the lake reforms, it causes billions of dollars in crop damage, displaces livestock, and floods local communities.
The region also faces environmental challenges, including severe land subsidence caused by decades of excessive groundwater pumping by farms. This overpumping has lowered the elevation of parts of the basin, ironically making the area more susceptible to flooding when the lake returns. The presence of the lake, even temporarily, also raises questions about water rights and the cultural significance of the ancestral lake to the Tachi Yokut tribe.