Can We Ensure the Future of Water?
By Scott Fields
Published Oct 1, 2013 8:00 AM
Maintaining a clean, sustainable water supply is fast becoming the defining challenge of 21st-Century Southern California. Facing the interlocking realities of an expanding population and predicted droughts created by climate change, the region is center stage in a global effort to find solutions.
Water is Los Angeles’ most precious resource and one of its most pressing challenges. In all likelihood, tomorrow’s weather report will be dry — very, very dry.
“We’re looking at historical and prehistorical records of drought that go back more than 10,000 years,” explains Glen MacDonald, UC Presidential Chair and UCLA Distinguished Professor of Geography and director of the university’s Institute of the Environment and Sustainability (IoES). “It’s not a rosy picture.”
In the 12th century, for example, the planet experienced pronounced hemispherical warming due to decreased volcanic activity and increased solar activity. During this period, California and the Colorado Basin suffered a drought of more than 50 years. In the coming years, climate change could bring back those bad old days.
“The more warming, the more likelihood of severe and extended drought,” MacDonald says, pointing to climate models suggesting that by the mid-to-late 21st century, the abnormally low rainfall levels in the Southland over the past few years may very well be the “new normal.” On top of that is a greater probability of 8-to-14-year droughts, such as the prolonged dry spell currently afflicting the American Southwest.
And that’s just a sip of what’s to come, say the experts. How do we ensure that the water we do have is drinkable? Can we create a sustainable water supply? From desalination to reuse to conservation, the challenges are varied and the answers not always clear.
Moreover, like so many other things, what happens in Southern California doesn’t stay in Southern California. Responses to the region’s water issues are being exported to dry lands from Africa and the Middle East to Pakistan, India, Australia and South America.
At the front of these efforts are dozens of UCLA faculty in science, engineering, law, public policy and social science, and Bruin alumni at environmental NGOs in Southern California. At the center of the idea flow is the UCLA Water Resources Group, founded in 2010 as part of the IoES.
Don't Let the Water Run
The water catchment area for Southern California, one of the largest in the world, extends out to Wyoming, Colorado and Utah, all areas prone to aridity. With other communities along the way vying for a portion of this water, and with environmental restrictions in place to preserve endangered ecosystems, there’s little hope of garnering more water for an expanding population from the usual supply-side sources.
The solution, then, must come from within the region’s boundaries. But those boundaries leak a lot.
“We must make better use of the water that falls on our city,” says IoES scientist Richard Ambrose Ph.D. ’82, a UCLA professor of environmental health sciences. “Right now we’re sending it out to the ocean as fast as we can, instead of taking advantage of it.”
It doesn’t help that so much of the urban area is covered with concrete — as are its gutters and storm drains — making it impossible for storm water to sink into the soil, or flow into wetlands where it can recharge the groundwater levels.
The installation of bioswales — essentially ditches planted with vegetation that absorb rainwater — is one solution. “When it’s dry around here, so many pollutants from vehicles settle on the concrete surfaces, and so much of that ends up going into the storm drains and out to sea,” Ambrose says. “Bioswales can be of great benefit.”
Restoring wetlands is another solution. The executive director of the National Estuary Program’s Santa Monica Bay Restoration Commission (SMBRC), Shelley Luce D.Env. ’03, is working with government, businesses and scientists from UCLA to restore Ballona Creek and Wetlands.
Luce also runs a project that has planted rain gardens and installed rain barrels at 900 homes in Los Angeles and nearby Culver City. In this project, rainwater either collects in the barrels to be used for irrigation, or else sinks into the ground where it is naturally filtered by the soil and returns to the groundwater or streams like Ballona Creek.
“The local groundwater agency has funded us to do the mathematical modeling necessary to figure out the best locations in the city to get green-street projects like these going,” says Luce. “We’re not only helping families save water, we’ve changed their perception of what the water cycle is all about. We’ve created hundreds of new conservation activists.”
Use Less, Reuse More
Expanding conservation and reuse practices reduces the tremendous energy necessary to bring water to Southern California from the Colorado River and Sacramento Delta, currently estimated to be about 20 percent of the state’s total energy costs. Wasted water in residential landscape is one culprit. At least 40 percent, and perhaps as much as 60 percent, of Southern California’s residential water is used for this purpose. But smarter planting and more efficient irrigation systems can greatly decrease dependence on imported water.
IoES Adjunct Professor Stephanie Pincetl Ph.D. ’85, director of the California Center for Sustainable Communities, is taking on a water infrastructure mapping project funded by a National Science Foundation grant. “It’s the first map of all the water entities in Southern California — the city water districts, the groundwater-management districts, the pumpers, the sanitation districts,” Pincetl explains. “There’s no transparency in the system now. This will make it much easier to measure the impact of changing conditions when it comes to the climate and other factors.”
Water-reuse projects at UCLA, in fact, have been ongoing for 20 years. IoES Professor Michael Stenstrom of the Department of Civil and Environmental Engineering recalls a Lake Arrowhead study conducted during a drought in the early ’90s. The study demonstrated the ability to take domestic wastewater and treat it to the point where it was cleaner than the lake water the population was drinking. But because the drought ended, the study’s recommended procedures were never adopted for permanent use.
Other reuse programs have had better luck, however. First implemented in 1975, a water-treatment plant completed in 2008 in Orange County is recycling 70 million gallons per day by pumping it down into a groundwater basin. A second plant in El Segundo is recycling 15 million gallons per day, and other small recycling projects are active in the West Basin Water District, a 185-square-mile area that includes El Segundo, Culver City, Inglewood and the South Bay. UCLA scientists and researchers serve on the advisory boards of many of these projects.
Stenstrom and UCLA desalination pioneer Yoram Cohen, professor of chemical and biomolecular engineering, are working on a low-cost residential reuse system in West L.A., where grey (waste) water is treated before reuse for home irrigation.