Water Pipeline Plan Sparks Concern : Projects: Opponents fear huge proposal in south Orange County will harm canyon lifestyles. Others call it vital.

The $625-million underground pipeline would be Orange County’s largest ever, tall enough to hang a basketball hoop at NBA regulation height and still have three feet to spare and wide enough to deliver 260 million gallons of water a day.

Its main section would be called the Cleveland Tunnel, an eight-mile project 2,200 feet beneath Bedford Peak in the Santa Ana Mountains and the Cleveland National Forest. Eighteen miles in all, the pipeline would link the western tip of the Colorado River Aqueduct--Lake Mathews in Riverside County--with two other underground pipes near Irvine. The imported water would satisfy the demands of future developers and a south Orange County population expected to grow by 100,000 in 20 years.

If approved by the board of the huge Metropolitan Water District of Southern California--an agency known for monumental water projects--the pipeline would be paid for by water users in its 5,200-square-mile service area from Ventura to San Diego County.

Backers say the project not only is vital for growth, but would serve as an alternate source of imported water in an emergency, particularly an earthquake, which could damage water lines and interrupt service. South Orange County is almost totally dependent on imported water.

“I think it’s critical, I’m a major proponent of it,” said Peer Swan, president of the board of directors of the Irvine Ranch Water District, the county’s largest district. “Right now, all the water coming into this area comes from one water plant. If we had an earthquake that affected that plant, then South County is out of water.”

But residents of the rural Modjeska, Williams and Silverado canyons in the foothills of the Santa Ana Mountains, who live near the tunnel exit, worry about what the project might do to their semirural lifestyles.

Although construction probably wouldn’t start for several years, talk of the tunnel has reached a fever pitch among residents of Orange County’s canyons in recent weeks as a deadline loomed this week for comments that will help shape the project’s environmental impact report.

A 24-hour-a-day construction project virtually in their back yards that could last four years might destroy the quiet ambience of the narrow, rustic canyons, some residents said in a letter to MWD officials.

“We don’t have any chance of stopping this. There’s no way in the world,” said Toni Doscher, a postal worker who has lived in Silverado Canyon for four years.

“(But) we would like it to be the least disruptive to the animals and the trees. This is the only place left in Orange County where you can still see a puma . . . where your grandkids can come up and see a creek with frogs in it. . . . We are doing our best to keep it that way,” said Doscher, who belongs to the Intercanyon League, an organization of about 900 residents from the three canyons.

The plan calls for 200,000 acre-feet of water a year to flow by gravity through the pipeline from Lake Mathews, a reservoir near Corona built in the 1930s that stores Colorado River water.

The water would then flow into a connection just north of the El Toro Marine Corps Air Station that would tie into two other major feeder pipelines: the Allen-McColloch line and the South County pipeline.

The Cleveland Tunnel would enter the 136,000-acre national forest through Bedford Canyon in Riverside County and emerge just north of Williams Canyon in Orange County, the smallest of the local canyons and home to only 11 families.

The pipeline is among $7 billion in capital improvement projects on the books over the next decade for MWD, the Los Angeles-based water agency that has built 130 miles of tunnels to distribute water throughout Southern California and whose board chairman is John V. (Jack) Foley of San Juan Capistrano, manager of the Moulton Niguel Water District in Laguna Niguel.

“I want to keep showing an effort for this project,” Foley said. “South County really benefits from it. This project also allows us to bring water in at high (pressure) that allows us to fill all the reservoirs and shut down the pump stations,” which saves energy costs.

Although the project hasn’t been approved yet, preliminary work is under way and MWD is already acquiring land for the pipeline’s right of way, including a citrus grove near Lake Mathews where a treatment plant will be built to make the lake’s water safe for drinking.

Perhaps the engineering hallmark of the project will be tunneling through the mostly hard rock under the forest. Geologist John Waggoner of Yorba Linda, the project’s consultant, said work crews will start on both sides of the mountains and meet in the center, much like the tunnel project that connects England and France via the English Channel.

Instead of the traditional method of drilling and using explosives, the excavating and laser surveying methods of modern times make it “pretty easy to meet in the middle,” Waggoner said. The large drills of today have more than 40 cutters, weigh more than 200 tons and operate on about 1,000 horsepower generated by electricity, he said.

But modern technology does little to ease canyon residents’ concerns over constant truck traffic in Silverado Canyon and on Santiago Canyon Road, which is the main highway to the canyons.

Residents are also fearful about how increased noise would affect the local elementary school and wildlife and the possible contamination of their underground water by the constant drilling.

A representative of the U.S. Forest Service, which oversees Cleveland National Forest, said its natural springs and underground waters are vital to the wildlife and will have to be closely monitored by MWD officials.

Adam Kear, MWD’s project manager, said district officials have met with the canyon residents in recent months.

“These are understandable concerns. We will continue to look for ways to further mitigate these problems . . . and we are counting on the canyon folks to help us come up with solutions,” Kear said.

Kear said “construction activity will be completely hidden from any homes” and that MWD is studying possibly rerouting the pipeline away from the canyon areas, which the canyon residents strongly support.

“The community wants to work with (MWD), but we sure don’t want to be mowed over by them,” said Judy Myers, a substitute teacher and 29-year resident of Silverado Canyon. She questioned who really benefits from the new water line and whether it would encourage further growth in South County.

“They say they need it for those people who are already there, but just like roads, once they get the water they can bring more people in,” Myers said.

MWD officials, who have held two public meetings in South Orange County this fall, will review all the comments and package them into a final environmental document to be presented to the MWD board of directors early next year.

If the board approves the project, permits would have to be sought from myriad government agencies, including the U.S. Forest Service and the state Water Resources Quality Board, Kear said.

Water Tunnel

A proposed $625-million, 18-mile pipeline that would deliver water from Lake Mathews in Riverside County to another underground pipe near Irvine involves drilling a huge tunnel through the Santa Ana Mountains and the Cleveland National Forest in Orange County.

Bringing Water to Orange County

Water from the California Aqueduct is pumped to the Diemer Filtration Plant in Yorba Linda, treated, and then distributed through four main pipelines to customers in Orange County. The proposed pipeline would connect to the Allen-McColloch pipeline near the El Toro Marine Corps Air Station.

Tunneling Machine

Tunnel-boring machine extends cutting face into mountain, chews up rock and removes debris by conveyor belt. A tunnel-boring machine begins at each end of mountain and digs toward center.

Tunnel machine extends digging surface

START (1-mile tunnel):

Lake Mathews (1,380 ft.)

8-mile tunnel:

Bedford Canyon (1,280 ft.)

Bedford Peak (3,691 ft.)

2-mile tunnel:

Santiago Canyon (1,160 ft.)

END:

El Toro Air Station (600 ft. elevation)

Source: Metropolitan Water District of Southern California