From the air, scientists map ‘fast paths’ for recharging California’s groundwater
As they walk along a narrow highway in northern California, two scientists point out a huge red sign on the pavement. It is a map of California’s aquifer system.
It is a map of California’s underground water system. It says that the aquifer system is a very fast-charging system — one that would recharge the groundwater at the rate of about 1,000 gallons per day over the course of a year.
But as the scientists show me on that narrow, two-lane highway, only about 0.8 of 1.0 percent of the aquifer system is rechargeable. The vast majority of the underground aquifer is a very, very slow-charging system that can only recharge the groundwater about once every 30 years.
That map is just one example of how California’s groundwater system is so much more complex than previously thought. This is one of the most important stories in California’s groundwater recharge debate.
The map may look like a simple one, but it’s actually very, very complex — and it’s a story that experts say should be looked at very, very closely.
“This is a really important story,” said Andrew Carrol, a water resources policy expert with the Center for Biological Diversity.
Carrol said he’s concerned about the consequences of making decisions on how much water the state needs to use.
Some of these decisions are technical and can be made by experts, like the ones who created the map in the first place. But there are also a lot of political and legal decisions that get made by state and federal officials who don’t have the expertise needed to make those kinds of decisions.
And when it comes to the politics and law, Carrol says it’s even worse.
“You’ve got a state government that has made some incredibly unwise decisions about the water, and now they’re getting to make some even more unwise decisions about the water,” he said.
The groundwater system in California is far from perfect, and much remains unknown about what the future holds. That’s why the debate over the state’s groundwater needs is so complex.
What does California need?
Over the past several decades, the state has been experiencing droughts in many of its major water basins.
One of those basins is the Imperial Valley, in which farmers grow tens of thousands of acres of