Often referred to as “green infrastructure,” much of the new technology could be a more accurate way of collecting rainwater from rooftops or sidewalks, and having it sift through porous concrete or grass fields into tanks for later use.
However, to make an impact, they said, it will require more government investment, technological advances, and overcoming political obstacles.
To learn more, The Washington Post spoke with Andrew Fisher, a professor of hydrogeology at the University of California, Santa Cruz, and David Feldman, director of the Water Institute at the University of California, Irvine.
The conversation has been edited for length and clarity.
What is rainwater technology?
Fisher: It’s kind of a two-piece. In general, stormwater management is, first and foremost, about mitigating risks, avoiding nuisance, avoiding flooding and avoiding damage. [that comes with storm rain].
But we know that storm water is also a potential resource. So another arm of rainwater management is figuring out what to do with some of that water. How can we curb it? How can we store it so we can use it later?
Why haven’t you already solved the droughts in California?
Fisher: When the climate changes, the stats change. Most of the rainwater infrastructure was built 20, 30 and 40 years ago, and much of it was built based on ancient data. So [drainage pipes] Which are built for 10 year events, 20 year events, and 30 year events are very small. Much of our infrastructure that was built decades ago is undersized.
Feldman: California plans to do a tremendous amount of work with rainwater harvesting and harvesting, but the actual implementation of these projects will take time. In many cases, it may take years.
Land must be acquired, things must be built, environmental assessment studies must be conducted, and perhaps most importantly, the public in the areas where this water is harvested must be brought on board.
How does rainwater technology adapt to solve droughts?
Feldman: Rainwater harvesting is a very old technology. You can go back to ancient Israel, for example, or other parts of the Middle East, where rainwater harvesting techniques were widely used.
So what is the new wrinkle? I would say this is the concept of green infrastructure – you don’t use a lot of concrete and build storage tanks and dams. Alternatively, you can come up with more appropriate and rational ways to use the natural environment such as gardens, wetlands, marshy areas or ponds for intermittent water storage.
But unless you’re really looking for it, it can be hard to tell the technology apart. You see parks that contain wetlands that kind of double as habitats for various forms of wildlife and are replenished by [and store] Is raining.
You’ll also notice that neighborhoods have increasingly impermeable surfaces. Impermeable surfaces are being replaced by grass, open fields and porous pavements to allow water to replenish, for example, aquifers. You also see on water storage tanks, those types of things.
Fisher: Twenty years ago, 30, 40 years ago, storm water was basically seen as a nuisance. But because of the drought, because of the increasing demand for groundwater, I can say that a big change is happening.
One of those areas is imaging what’s below the surface, better understanding where the water is, and where the storage space is. We need to use underground storage because you simply can’t store enough rainwater on the roof.
Will Stormwater Technology End California’s Droughts?
Fisher: I’d say no. Drought is highly variable. [And] California’s climate oscillates between very wet and very dry conditions. Collecting rainwater doesn’t change any of those things. But what rainwater technology can do is be part of the solution.
Feldman: Rainwater harvesting [is] piece of a complex puzzle. It will not solve all our problems, but it can solve a tangible part of our problems.
We may not want to use rainwater for drinking. However, this water can be treated with different degrees of reuse, at least in order, for example, to irrigate plants or irrigate landscaping.