California has had so much rain over the past few weeks that it has flooded farmlands and torrented normally dry streams and ditches into the ocean. However, much of the state is still suffering from severe drought.
The massive runoff of rainwater during droughts begs the question — why can’t we collect and store rainwater when we need it for the long, dry springs and summers?
As a hydrogeologist at the University of California, Santa Cruz, I am interested in what we can do to collect large-scale runoff from storms like this. There are two main methods of water storage. One is to store water behind a dam, and the other is to put water in the ground.
Why isn’t California getting more runoff now?
When California hits the atmospheric river-like storms of December 2022 and January 2023, water managers across the state will likely shake their heads and ask why they can’t keep the water any longer. I ask if Reality is a complex issue.
California has large dams and reservoirs that can hold large amounts of water, but they tend to be in the mountains. And when it’s nearing capacity, it needs to release water in preparation for the next storm. Much of that water ends up in the ocean, unless there is another reservoir downstream.
Video captures flooding from record rainfall on the last weekend of 2022.
One reason rainwater runoff is not automatically collected for large-scale use in more populated areas is that the initial runoff from roads is often contaminated. Flooding can also cause septic systems to overflow. Therefore, the water must be treated.
The water taken does not have to be drinking water and can be used on the golf course. But then you would need a place to store the water, and since it can’t be in the same pipe as your drinking water, you’d need a way to distribute it using a separate pipe and pump.
