Cover Reservoirs as a Precaution? Many Neighbors Just Can’t See It

Times Staff Writer

In the Los Angeles value system, a water view ranks high, up there with a sleek, fast car and Laker season tickets. The beach people watch the water from the shore, with close-up vistas of breaking waves. The canyon people see it from the mountains, where the most prized panoramas include a patch of distant ocean blue.

And while the reservoir people may have a less spectacular view, it affords them no less pleasure. From Elysian Park in the east to Pacific Palisades in the west, they jog and bicycle around, and gaze from windows and decks upon, their ersatz lakes.

No matter that most of the reservoirs are lined with concrete and regular in shape. No matter that intake valves and maintenance trucks are an integral part of the scene. The mere suggestion of nature in the city is enough.

But at reservoirs around Los Angeles, the waterfront life may be coming to an end.


The city Department of Water and Power is reviewing 10 of 15 open reservoirs as candidates for metal roofs or floating rubber covers to minimize exposure to potential health hazards.

Over the last decade, 45 open reservoirs around the state have been covered or replaced by holding tanks. But 70 remain uncovered, and Los Angeles has more than any other water district in California.

The city’s recent efforts to change that have unleashed a sharp debate echoing similar controversies around California and in scattered locations across the country.

In the hills above Newport Beach, plans to put a cover on the San Joaquin Reservoir, Orange County’s largest, has drawn opposition from some nearby residents. Waters experts claim that the reservoir is open to the elements, subjecting it to contamination from bird droppings, insect larvae and algae-associated bacteria.


In the past, midge fly larvae have shown up in coastal area tap water, and four years ago, officials had to remove nearly a million African clawed frogs from the San Joaquin Reservoir.

Homeowners who live nearby have been divided on covering the reservoir. Those who live in homes that cost up to $400,000 claim that the water is fine and resist covering it.

In July, the Metropolitan Water District of Southern California was authorized to spend $380,000 to perform preliminary engineering and environmental studies to find ways to improve the quality of the reservoir’s water. Discussions by homeowners, however, have not led to any specific proposals as alternatives to covering the reservoir.

The controversy among homeowners who live near San Joaquin Reservoir and water officials is typical of the debate with other reservoirs in Southern California.

On one side are water treatment experts, who speak of trash and animal waste and carcinogens that could be shut out from the water supply if reservoirs are covered. They say the water in those reservoirs meets federal health standards now, but some of those standards are expected to change in the next three years.

On the other side are those who depend on reservoirs for visual pleasure as well as for drinking water. They question the necessity for drastic measures that would alter the character of their neighborhoods.

“There’s no problem now. They’re perceiving that in the future, there might be,” said Stephen Bost, who lives near the Santa Ynez Reservoir in Pacific Palisades. “I’m not buying that there’s not another method. . . . I don’t want to drink bad water and get cancer at the expense of a view. But damn it, if it’s not needed, why do it?”

Already, the Los Angeles Water and Power Department has placed a tan, corrugated aluminum roof on DeSoto Reservoir in Chatsworth. By next week, a black rubber cover, so strong a person could walk on it, will float on top of Eagle Rock Reservoir. DeSoto, however, is bordered by a freeway, and Eagle Rock can be seen only from the road to a nearby dump.


Now, in its first tentative steps to cover the visible reservoirs, the DWP is running into stiff opposition.

A group dedicated to preserving Elysian Park took the city to court to ensure environmental studies of a plan to spend $3 million to cover a reservoir there, which is bordered by a jogging path. In June, the city announced it would prepare a preliminary environmental impact report.

“They’ve got to have some responsiveness to being in a park,” said Sallie Neubauer, president of Save Elysian Park Committee. “They can’t just thumb their noses at the people.”

The reservoirs under consideration range in size from 3.2 to 14.6 acres.

Individual filtration plants will probably be built at each of the large reservoirs. But that poses its own problems: The plants cost $20 million to $30 million each, and four to six acres of land to accommodate the plants must be found.

For more than 10 years, the state Health Services Department urged local utilities not to store potable water in open reservoirs once it has been treated. The state recommended covering distribution reservoirs in a 1974 letter to the DWP. The city was slow to respond.

“Mainly, it was cost, a decision of not spending money to cover them,” said Henry Venegas, the water system’s assistant engineer of design.

Became Target


But Los Angeles became a target for the state after the $146-million Sylmar filtration plant was completed in late 1986.

After the water is filtered, it is distributed to the reservoirs, just a pipeline away from consumers’ faucets.

“That’s why the push is on now,” said Tim Gannon, an official with the state health department’s public water supply branch. “Because you have this treated water, beautiful water. The quality now is great. It’s a shame to have it sitting out in those open reservoirs.”

The risks, he said, are varied:

- Sea gulls that forage in landfills and drop their pickings in coastal reservoirs.

- Beavers, like the ones that called a Nevada reservoir home, leading to an outbreak of severe diarrhea among water customers.

- The African clawed frogs that were banished from San Joaquin Reservoir in 1984.

Even though chlorine is added to water as it is carried to taps, the disinfectant does not provide as thorough a cleansing as the Sylmar plant does.

“Is that enough (contamination) to hurt us or not?” said Bruce Elms, standards engineer for a trade group, the Denver-based American Water Works Assn. “We’re getting to where we say, ‘We don’t know. But prudence says if it’s there, get it out.’ ”

Another concern is trihalomethanes (THMs), a class of compounds that includes chloroform. Studies during the 1970s showed that rats and mice develop liver and kidney cancer from exposure to THMs. Algae combined with chlorine forms THMs.

In 1979, the Environmental Protection Agency concluded that drinking supplies should not contain more than 100 parts of THMs for every billion parts of water.

Meet Test

The Los Angeles reservoirs easily meet that test. Venegas said they contain THMs in the 30- to 35-p.p.b. range.

But the EPA plans to revise its THM standard by January, 1991.

Getting rid of the chlorine is not a good idea, Clark said, because the chemical stops cholera, typhoid and parasites. A roof or cover, however, would cut off sunlight, Venegas said, which would prevent algae from blooming, thus reducing the THM level.

Elsewhere, these aims have been accomplished while nearby residents were mollified.

In the Oakland-Berkeley area, for example, the East Bay Municipal Water District put landscaping and reflecting pools on top of sturdy roofs at three of six covered reservoirs. In Orange County the Metropolitan Water District of Southern California is considering storing drinking water balloons beneath the surface of San Joaquin Reservoir. Venegas would like to avoid such costly measures.