May 26, 2023 - Tulare Lake Reappears

May 24, 2023 June 6, 2022

A record-breaking snowpack accumulation in the Sierra Nevada in the winter of 2022-2023 along with unusually heavy spring precipitation has brought Tulare Lake back to life. On May 24, 2023, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a false-color image of Lake Tulare filled with an abundance of water.

In this type of image, water appears deep blue, open land looks tan, vegetation is green, and cloud can be white or tinted light blue, while snow appears bright electric blue. The deep blue Tulare Lake is the largest lake in the image, filling the lowest point of the San Joaquin Valley Basin. Several rivers and other lakes are visible, including Kern Lake (south of Tulare). All are filled by the recent rains as well as the “big melt” frees water from snowpack. Meanwhile, the mountain peaks remain covered with snow. A cloud bank covers the lower left (southwest) portion of the image.

To truly appreciate the change brought about by the big melt, click the dates to reveal a second Terra MODIS image of the same area acquired on June 6, 2022. Here Tulare Lake is essentially non-existent, and the lakebed is covered by agricultural fields. Kern Lake is visible, but very small compared to the May 2023 image.

Tulare Lake was once the largest freshwater lake west of the Mississippi River, covering about 1,800 square miles of the Valley floor and stretching about 60 miles from north to south. In the 1870s, Tulare Lake was a productive fishery as well as providing as many as 300 dozen terrapins (a type of turtle) to market each year. Even at that time, the lake waters rose and fell seasonally— sometimes leaving barely any water in the heat of summer— and strong winds could move the shorelines several miles over just a few hours.

Since the 1920s, the rivers that fed the lake have been dammed and diverted for agriculture and other uses. The lakebed has since been covered with farms that produce a variety of crops and livestock. Since that time, cities have sprung up on the edges of the historic lakebed, including Corcoran, the largest city in the vicinity. The revival of Tulare Lake has brought floodwaters into Corcoran, and they began to arrive as early as March. The town responded by shoring up its levees, which had protected the town from previous wet years but may not be tall enough by the time this year’s big melt delivers all the snowpack into Tulare Lake.

According to the California Department of Water Resources (DWR), as of May 25 the statewide snowpack was 310 percent of average for this date, among the largest ever recorded. The snowpack in the Southern Sierras was an even more impressive 407 percent of average for this date. The size and distribution of this year’s snowpack is posing severe flood risk to some areas of the state, according to DWR, especially in the San Joaquin Valley.

Image Facts
Satellite: Terra
Date Acquired: 5/24/2023
Resolutions: 1km ( B), 500m (356.6 KB), 250m (200.7 KB)
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC