Out of sight, out of mind. That appears to be the philosophy of some water managers in California.
When surface water is plentiful, groundwater in most areas is seen mainly as a supplemental source of water for urban, industrial and agricultural users.
In reality, however, it is more than a supplement; groundwater supplies up to 16 million acre-feet of the state’s water, or up to 23 percent of the water used by people in California. That’s more than three times the amount of water supplied by the Colorado River.
During the past four years, drought has forced farmers in parts of California — the Tulare Lake Basin and the Central Coast especially — to rely almost exclusively on groundwater for their crops. As a result, some parts of California have seen underground water levels drop by more than 10 feet and some by more than 50 feet.
There are two ways to look at California’s groundwater. Either the glass is half empty, or it’s half full.
Those who see it as half empty believe the only way to stop the drop in groundwater levels is to stop farmers and others from irrigating their crops and stop cities and other users from withdrawing water.
Those who see it as half full see the opportunity to work with farmers and others to allow them to irrigate their crops and provide water to other users — and use their land to replenish the aquifers below. According to Thomas Harter, a professor at the University of California, the drawdown of groundwater has created 20 million to 40 million acre-feet of storage space underground. If these aquifers are recharged during the wet winters, they can serve as “banks” to supply water during dry periods.
This is an opportunity. By recharging the aquifers of the Central Valley and other regions that have been drawn down during the four-year drought, California’s water managers can store water enough to avoid future shortages.
This sounds amazing, and it is.
In addition to building more surface water storage in the form of dams, California can take excess winter runoff and use it to recharge aquifers. The result could be up to 40 million acre-feet of water ready for use in times of drought at a fraction of the cost of dams.
The concept of aquifer recharge is not new. Some Central Valley farms are doing it right now, as are water managers in such far-flung locations as Idaho and Oregon.
In Helm, Calif., farmer Don Cameron is using excess winter runoff in the Kings River to flood his land to recharge the aquifer below, replacing the groundwater he used last summer.
The result is a win for him and other water users in the area. His soil and orchards get a dose of much-needed moisture, and the aquifer below is replenished, with water available when drought returns — an inevitability in much of California.
Water is not an issue in the West; it is the issue. Every groundwater basin — there are 515 in California alone — needs to be managed in a way that keeps farmers, industry and cities well-supplied. The way to do that is to make sure water is well-used, but also to make sure excess runoff during the wet winters is stored either in reservoirs or in aquifers.
That will assure California of a solid economic future and assure Californians that their glass will always be full.
Right now, that seems like a dream, but in the future, with cooperation and creative management, it can become a reality.