It is easy to forget that California’s Tulare Lake, in the southern San Joaquin Valley, once competed with Lake Cahuilla (the “Salton Sea”) for the title of “largest lake west of the Mississippi”.
We drained it. We farm it. But as Erica Gies happily reminds us at every opportunity, water is a formidable adversary if we aren’t willing to make peace with it.
It is easy to forget that the Tulare Basin once held a very large lake, covering more than 1,000 square miles. The lake was very productive, with vast tule marshes teeming with fish and waterbirds that supported numerous Native American tribes. In very wet periods, it got deep enough (more than 40’ deep) to spill over into the San Joaquin River. In surface area, it was the largest water body west of the Mississippi, surpassing even the Great Salt Lake.
But in the 1900s, inflow to the basin was tamed by a combination of levees, dams, and canals, allowing farming throughout the region. Despite this, every few decades, nature recaptures a portion of the old lakebed when flows from the four rivers that drain into the basin—the Kings, Kaweah, Tule, and Kern—overwhelm the ability of landowners to move water around to avoid flooding their fields.
The last big cabin-crusher of a snowpack happened in 1983. That year, a young John Fleck got “trapped” in Chico, California, by the bodacious runoff (the scare quotes a reference to the fact that 23-year-old me being stuck in a party town with a delightful traveling companion and no particular need to be anywhere else was not a bad thing). In 1983, according to Mount’s PPIC post, 100,000 acres of Tulare’s former lakebed, now turned lucrative farmland, ended up under water.
There’s a good chance of something along those lines happening again this year – the water has to go somewhere! But Mount notes a fascinating “wrinkle”:
For the past decade, extensive groundwater withdrawal has lowered portions of the Tulare Basin, including areas both in and around the historic lake. This is likely to have two impacts. First, flooding may affect a potentially wider area that’s now lower and within reach of flood waters. Second, even though infrastructure that’s used to move water around in the Tulare Basin is critical to managing floodwaters, subsidence has altered the slope of many irrigation canals, reducing their capacity to move water. It’s not yet clear how this will impact flood management, but it could pose a challenge.