FIGURE 1: The Central Valley is a highly modified agricultural landscape. SOURCE: Big Think

A few years ago, I was delighted to see an geographer’s rendition of what a satellite image of California would have looked if such a thing existed in the 1800s (figure 1). Back then the southern San Joaquin Valley was swampy wetland surrounding Lake Tulare, the largest freshwater lake west of the Mississippi River.  In the late 1800s, canals and dams were created to divert water from the rivers that fed into the lake to go supporting agriculture and the metropolitan areas of California.  As the very shallow lake dried up, the lakebed was converted into was converted to agricultural land, mainly under cotton cultivation. 

Figure 2: The Tulare Watershed with dry lake beds that are refilling. Source: KVPR

California and much of the wast have had far more precipitation than expected on the heels of years of drought. The existing canals and reservoirs in the watershed are overflowing and the dry lake bed with fields is getting flooded again; water doesn’t care about what is there now, it just flows downhill. Enter the 2023 version of Tulare Lake flooding farmland, roads, railways, towns, and other expensive infrastructure.

While it won’t return to its historic levels with one year’s snowpack, it’s likely that 100,000 acres (150 sq. miles) of farmland will be under water for two years, possibly more. This is a relatively lightly populated region, but some cities like Corcoran, CA (22,000 people) are on the edge of the old lake bed and might need to be partially evacuated as levees have failed to stem the tide. 

Agricultural companies and local towns are both trying to protect their lands from flooding to protect their infrastructure, equipment, homes, and people.  At times, these goals are at odds with one another, and armed guards are protecting levees and hydrologic projects. Below are two videos that are good introductions to the topic of the reemergence of Lake Tulare.   

Questions to Ponder: How has agriculture and urbanization modified your state’s geography? What are the positive impacts of these modifications? What are potential negative consequences of these modifications?

TAGS: environmental modification, California, environment.

VIDEO#1: Limited geography, but a good 4 minute local news-type explanation.
Video #2: More in-depth (15 min.), with historical background on the hydrology of the region.
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