Rainfall Windfall

Two weeks of record downpours wrought death and loss, yet represented a lost opportunity: If not for Southern California’s careless approach to its water problems, the rains could have put a much bigger dent in the region’s years-long drought.

Although the rainfall will help replenish the state’s reservoirs and aquifers, it was a dramatic demonstration of why planners need to capture more of the billions of gallons of water that flow each year through a thirsty Los Angeles into the ocean.

Yes, billions of gallons. With so much of the city paved and built over, officials estimate that a half inch of rainfall within a 24-hour period can put 3 billion gallons into just the channels draining to Ballona Creek. Because the average Department of Water and Power customer consumes 150 gallons a day, that much water could go a long way. Instead, most ends up funneled into drains, rivers and creeks.

This month’s rains were so heavy that even the most ambitious storm management plan might not have prevented the devastation. But if more rainwater were naturally filtered and stored in local aquifers or cisterns, come July residents could be sprinkling their lawns with a clean conscience. Currently, half of the city’s water supply goes to landscaping.

A 120,000-gallon cistern, basically a giant concrete tank, was recently buried at the Open Charter School near LAX. Before, the asphalt parking lot and playground often flooded. Crews removed much of the asphalt and installed lawns and swales. They then landscaped or graveled areas designed to trap and filter rainwater as it trickles into the cistern. The school now has two grassy fields, new trees and its own underground water supply for landscaping and firefighting.

In Sun Valley, city and county officials are working together to re-engineer the area’s 2,700-acre watershed. One part of the project involves installing filtering devices at Sun Valley Park to collect rainwater and recharge local aquifers. When it is completed, residents should get relief from perennial flooding, as well as a new jogging path, trees and lighted athletic fields.

Andy Lipkis, the founder of TreePeople and longtime advocate for smarter water management, dreams of installing 10,000 cisterns and other devices to capture water countywide. His goal, shared in concept by a growing number of water agency managers, is to cut the amount of water the region imports by half. Currently the city of Los Angeles imports 85% of its water.

This doesn’t require any gee-whiz technology. The tough part will be getting more public officials to cooperate across agency lines and treat rainfall not just as a problem to be solved by laying bigger drain pipes but as an opportunity to restock local supplies. That thinking is already much in evidence -- in Sun Valley and elsewhere -- but this month’s deluge should spark redoubled efforts.