Hydrogeology of the Kern River

Hydrogeology of the Kern River

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In the old days, before Bakersfield became a major city, the Kern River flowed south through now-vanished swamps that covered much of the area that the city occupies today. From these swamps, the river continued southward to Arvin, and finally flowed into Buena Vista Lake, which back then covered thousands of acres. The lake overflowed regularly and sent volumes of water down the San Joaquin River, but canals have removed much of the river's might and no overflow has left the lake now for many decades.
The river in the 1850s flowed in a south-trending channel on the east side of the valley, but a flood in 1862 cut a southwesterly channel several miles to the west, pretty much along the route of the the modern Old River Road. Another flood around 1869 removed snags and debris, and moved the channel to its present course. In the meantime, the Bakersfield swamps were drained and filled in, enabling settlers to move into the area that is covered today by downtown Bakersfield.
Floods plagued Bakersfield for many years, as snow melt regularly swelled the Kern River to a raging torrent. This continued until the 1950s when the Isabella Dam and Reservoir were constructed to help regulate the river flow. In fact, the dam saved Bakersfield from flooding in 1966 when some 598,400 gallons of water per second rushed down the Kern River Canyon, nearly bringing the level of Lake Isabella up to the spillway.
Today, the river encounters its first diversion into a canal when the river first exits out of the Kern River Canyon. It then encounters another diversion when it reaches the east side of Bakersfield near Hart Park. Water agencies measure the river flow at a point just west of the park, and the flow here determines the size of water allocations that are allowed to flow down canals to farms throughout the valley.
The first two of seven diversion weirs in town - the Bearsdley and the Rocky Point weirs - are visible from the Panorama Bluffs in northeast Bakersfield. Canal water from there flows north and south to irrigate farm fields. In total, the river is diverted into seven canals that run through town before what remains of the water finally flows into the remnants of Buena Vista Lake, which these days is but a shadow of its former self.
The river provides up to 700,000 acre-feet of water each year, which represents the same volume as 700,000 football fields covered by a water depth of one foot. Kern County also receives amn addiitonal 400,000 acre-feet annually from the Central Valley Project, which is represented by the Friant-Kern Canal, and another 1 million acre-feet from the California Aqueduct. However, water supplies from these aqueducts are cut in half during some years when droughts precent an adequate amount of rain from the mountains to replenish the streams.
Interestingly, even though Bakersfield has an extensive water-charged, underground aquifer, about 80 percent of the drinking water used in town is supplied from wells. In fact, less than 20% of the water need for the city actually comes from the river, as most of the river water is used to irrigate thirsty farm fields.
There were many shade trees along the Kern River up until the 1940s and 1950s, but diversion of the river water into canals for farm irrigation dried up the river banks and killed off most of these trees in the the years that followed. Regrettably, the policy for many years was to meet the irrigation needs first, allocating to the river bed only what water was left over. This meant that in drought years the river dried up. However, as homes and businesses have grown up along the river banks, a community desire has developed to keep water in the river bed year round, both for recreation and to recharge the water table. Thus, water policy today is changing, and the needs of the river increasingly are being put before those of agriculture. This has led to considerable controversy, and many compromises will need to be made in the future to satisfy the needs of both farmers and homeowners.