Too Much Water Under the Bridge

In 1938, with no other choice, the U.S. Army Corps of Engineers began channeling the Los Angeles River to prevent flooding. This ultimately resulted in the 51-mile-long, mostly concrete-lined storm sewer that exists today. Although the river controlled flooding during this winter’s near record-breaking rainfall, it failed the region in three critical ways.

It wastefully flushed billions of gallons of water down its channel and into the ocean in an arid region that imports most of its water. It is a scar across the face of the city. And, most seriously, with increasing population and expanding development that paves over more land, the river probably will not be able to convey major storm waters in coming years unless its capacity is increased and/or the storm water is dealt with otherwise.

The time has come to approach the river differently.

First, we must capture more storm water before it reaches the Los Angeles River. That means addressing the river’s watershed -- the entire geographic area that drains into the river -- and its ability to collect and absorb storm water. Unfortunately, much of the river’s watershed has been paved over.

So we must find creative ways to capture storm water in the watershed and recharge the groundwater. Our heavily developed metropolitan area doesn’t have adequate open space to allow for construction of regional storm water detention basins, which are used by some other cities, such as Houston. The key is, therefore, to make every square foot of existing open space more porous. We can also harvest rainwater from rooftops and design new buildings with green (landscaped) roofs that will absorb water. We also should continue to plant trees throughout the watershed to slow, intercept and absorb storm water.

Another approach is to remove paving or replace impervious paving with porous materials to increase storm water infiltration areas. A recently completed project at a Westchester elementary school, for example, replaced asphalt with landscape, planted hundreds of trees and shrubs, and added a 110,000-gallon cistern to store rainwater for irrigation.

We must also revitalize the Los Angeles River itself. In February, the Los Angeles Bureau of Engineering issued a “master plan request for proposals” to do just that. What can that accomplish? Its cohesive framework would protect the river’s flood-control capabilities, create opportunities for adding vegetation and possibly for establishing fish and wildlife habitat, and provide a place for people to enjoy where vibrant, new development could occur with time.

An essential component of the planning process will be strong public involvement through community workshops. Angelenos, in cooperation with governmental agencies, should participate in the planning, design and ongoing maintenance of the river improvements.

Los Angeles is still a young city. With the proposed revitalization of the Los Angeles River, we have the opportunity to transform the city for a better future. Such opportunities come along, at most, once in a generation. In the 1850s, New York City purchased the land to create Central Park when many naysayers said it was a waste of money. In the 1990s, on the heels of a natural disaster, San Francisco rebuilt its Embarcadero waterline, creating one of the world’s great promenades and jump-starting development along its long-derelict edge.

Giving Los Angeles the river it wants -- and deserves -- is this generation’s great opportunity and its great challenge.

Nancy L. Fleming is a principal in an international planning, urban design and landscape architectural firm.