Dam Proposed for San Juan Creek on Caspers Park Land

Four south Orange County water districts, affiliated as the San Juan Basin Authority, are studying the possibility of building one or more dams in San Juan Canyon east of San Juan Capistrano to store runoff rainwater that, they say, now “is just wasted” by being allowed to flow into the ocean.

One of the proposed dams would be along San Juan Creek just east of Ortega Highway, where it passes through Ronald W. Caspers Wilderness Park. That has brought strong reactions from at least one conservation group, the Sea and Sage chapter of the National Audubon Society.

The dam at Caspers park, according to T.J. Meadows, general manager of the authority, could be as high as 60 feet and hold up to 30,000 acre-feet of water, much of which could be treated and used as drinking water. (An acre-foot is the amount of water needed to cover a one-acre area one foot deep and is equal to 325,900 gallons.)

The dam would also operate as a flood-control structure, he said.

Meadows said the studies “are just in the beginning stages” and are in conjunction with an application for a $41.6-million grant from the federal Bureau of Reclamation, which must be submitted before the end of May.

Virginia Chester, president of the Audubon chapter, said about the Caspers dam: “We are adamantly opposed to such usage in a public park. We certainly do not want to see any part of the park inundated, which could affect the habitat of plants and animals.”

She said she was in contact with another group, the Caspers Volunteer Naturalists, and would work with them against the dam proposal in whatever manner possible.

In addition to the Caspers site, which would be a mile south of San Juan Hot Springs, Meadows said smaller dams are being considered along the creek where it meets Verdugo Canyon, very near the park’s entrance, and at Gobernadora Canyon, about 3 miles toward San Juan Capistrano from the park.

Meadows said he doubted that the federal grant would cover more than the larger dam upstream, in which case the authority--made up of the water districts of Capistrano Valley, Capistrano Beach, Santa Margarita and Moulton-Niguel--”might do their own financing, probably of the smaller Verdugo dam, which would hold between 15,000 and 20,000 acre feet,” not for flood control but strictly for storage “to improve the groundwater level.”

“We do need more water in the south county, rather than bringing it in from 500 miles away,” he said, referring to the Metropolitan Water District bringing water from Northern California and the Colorado River.

Bill Knitz, general manager of the Santa Margarita Water District and chairman of the the San Juan Basin Authority, said the “whole project is just getting started.”

“We need environmental impact reports, which we hope to get started on in a few weeks, and we need to get our funding lined up, among many other matters,” he said.

“In the meantime, we hope we can get it all together and solve our water and flood-control problems. As it is, fresh water is just wasted in the ocean.”

San Juan Creek starts high in the Santa Ana Mountains, not far from the border of Riverside County. In the rainy season, it is fed by small tributaries, including those of Verdugo and Gobernadora canyons. In the southern part of San Juan Capistrano, it joins Trabuco Creek, then empties into the ocean at Doheny State Beach.