Notebook

How California Can Make the Most of Its Rainfalls

Now that rain is finally falling, is California doing all it can to capture and conserve that water? Projects are underway to utilize stormwater better, with several areas of Southern California already leading by example.

Water Deeply | January 23rd, 2017

The deluge that hit California this month may have eased some people’s concerns about the drought. But it also raised a new question: Is the state doing enough to capture all that excess stormwater for later use?

According to Annalisa Kihara, chief planner at the State Water Board’s Strategy to Optimize Resource Management of Storm Water unit (STORMS), the strategies for capturing and conserving rainwater are abundant, and numerous projects are underway. But changing the public’s and urban planners’ negative perception of stormwater – and budgeting for the sizable infrastructure improvements needed to meet ambitious water capture goals – remains a challenge.

“We designed our infrastructure in California to take that stormwater and send it out to the ocean as fast as possible, treating it as a hazard or waste,” said Kihara. Now STORMS, other state agencies and some cities are working to change that narrative. “It previously got folded into the sewer fee, so your taxpayer money is taking that stormwater and routing it away. [But] the drought has made us look at what sources of water we can depend on other than Sierra snowpack, and along with desalination and recycled water, what about stormwater? We want the public to look at it from a different perspective: less as waste, and more as a resource.”

Some farmers in the Central Valley are ahead of the game, already turning to innovative techniques for stormwater management, such as letting their fields flood over in winter to replenish underground aquifers rather than diverting or draining the runoff. But for municipalities, changing urban habits isn’t as simple or direct.

The State Water Resources Control Board received $200 million for the Storm Water Grant Program from Prop. 1, the Water Quality, Supply and Infrastructure Improvement Act of 2014. STORMS produced a report last year laying out a 10-year vision and implementation strategy for stormwater capture. The plan focuses on 23 projects, nine of which are already underway, including developing watershed management guidelines and tools, eliminating barriers to stormwater capture and creating stormwater data systems. Now, after widespread flooding this month, cities may be feeling more impetus to speed up the programs.

So what does improved urban stormwater infrastructure look like? For starters, it means more low-impact development, using less asphalt and concrete that routes water away, and more ground space and porous materials – such as pervious concrete, asphalt and pavers – that slows runoff and allows it to sink into the ground. Use of cisterns and rain barrels is a practical, cheap way for homeowners to capture and store rainwater; another technique is to disconnect the downspout drain from the roof so rainwater doesn’t go directly into the drain but can filter out across a lawn or yard. In the realm of landscaping, bioretention basins are a great way to create depressions in the ground that let more water infiltrate down.

Early Progress in Southern California

Early leadership in stormwater capture is coming mostly from Southern California, due to the region’s near-total reliance on water imports from the north and out of state. Santa Monica, for example, now requires stormwater permits for all new construction. The Elmer Avenue project, near Hollywood Burbank Airport, tackled the area’s chronic flooding problem by creating an advanced stormwater capture system, which not only employs catch basins and bioswales but also uses underground vaults to recharge the aquifer. Santa Barbara has installed pervious pavers in parking lots to increase its underground water supply.

Perhaps most impressive is the work being done in Orange County, where not only is stormwater being collected in infiltration ponds – large-scale lakes (unlined at the bottom) that allow water to permeate beneath – but also wastewater is being treated and recycled into the groundwater system. The Orange County Water District, working in partnership with the U.S.Army Corps of Engineers, has reportedly captured more than 20,000 acre-feet (24.7 million cubic meters) of stormwater since Dec. 15. In particular, the Santa Margarita Water District has created basins designed to divert runoff in residential areas using inflatable dams, which send large amounts of water into the county’s basins before pumping it up to reservoirs.

Last summer, the Los Angeles Department of Water and Power released its Stormwater Capture Master Plan, focusing on three large rainfall collection projects in the San Fernando Valley aimed at recharging the underground aquifer. “These storms are providing a lot more opportunity for stormwater capture than we’ve seen in the last five years,” said Deven Upadhyay, head of Waste Resource Management at the Metropolitan Water District of Southern California. Metropolitan today offers residents $35 rebates on rain barrels and $250 or more on cisterns; in the year and a half since the incentive program started, it has processed 44,000 applications. “It’s a lot, it’s more than we thought we would get,” Upadhyay added, and “the people who install those barrels now are seeing the benefits.”

Not only that, 70 percent of people who bought rain barrels have reported that they followed up with other landscaping changes to address water capture and conservation elsewhere on their properties, which “suggests it’s having a positive impact on the way people are thinking about water use in general.” Metropolitan offers classes, both online and off, to teach people about different groundcover options for stormwater capture, from mulch to bioswales.

Seeking a Broader Shift

Efforts like these will help drive STORMS’ goals, but in many cases cities need more guidance and help as they begin to shift their priorities toward better stormwater capture. “We had a lot of rain recently, and a lot of municipalities are now going to be looking at flooding areas where they want to address these issues, and collaborate with stormwater resource groups to create multibenefit projects,” said Kihara.

Stormwater capture efforts have been hampered by Prop. 218, known as the “Right to Vote on Taxes Act,” passed in 1996, which limited local governments’ ability to tax property owners but exempted water, sewer and garbage rates, which can be raised without taxpayer consent. This means when a city needs to raise fees to expand its wastewater treatment system, it can. But making infrastructure investments for better stormwater capture doesn’t fall within those exemptions. As a result, cities have a hard time raising fees from taxpayers directly, who see the expenditure as just one more tax.

Despite the barriers, stormwater capture is here to stay as California seeks to broaden its solutions in preparing for a drier future. Even if more robust capture and storage strategies were already in place, some water would inevitably be lost due to the severely heavy rains experienced of late. “I don’t want to create the picture that the amount of rain of the last couple of weeks is the norm,” said Kihara. “Even if Sonoma or Sacramento County were designed for stormwater capture and use, the amount we just received would surpass that.”