With a loud roar and a cascade of dirt, a 250-ton mechanical mole punched through the earth's surface recently, leaving in its wake a large-diameter tunnel, 8 miles long, to serve as a critical water line for Southern California.

The breakthrough completes the 220-foot-long tunnel boring machine's year-and-a-half journey through the rocks and dirt up to 800 feet beneath the Badlands mountain range in Riverside and San Bernardino Counties, as part of Metropolitan Water District's Inland Feeder project.

Phillip J. Pace, chairman of MWD's board of directors, says with this event, "Metropolitan breaks through not just to the other side of the mountain, but to the future. This is an important milestone for our Inland Feeder project, a vital link in securing a more reliable, higher-quality water supply for Southern Californians, while helping to protect the environment in Northern California."

The Badlands tunnel is the longest of three tunnels needed for the nearly 44-mile-long Inland Feeder, a high-capacity, gravity-fed water delivery system stretching from the foothills of the San Bernardino Mountains to the Colorado River Aqueduct in the Riverside County community of San Jacinto.

When completed in 2007, the Inland Feeder will offer Metropolitan the flexibility to deliver water from the San Francisco Bay/Sacramento-San Joaquin Delta in Northern California during strategic times - primarily during the winter when water is abundant and when it will minimize impacts to its ecosystem.

The feeder also will improve the quality of Southern California's water supply by allowing more uniform blending of water from the state project with Colorado River supplies, which have a higher mineral content.

"Southern California is facing increasingly limited periods of time when water can be drawn from the Bay/Delta and delivered to our region," Pace says. "So when water is available we must be prepared to move large volumes of water during a relatively short time, and then store them for use during dry periods and emergencies."

First envisioned nearly 15 years ago, the Inland Feeder will deliver water to be stored in surface reservoirs, such as MWD's Diamond Valley Lake near Hemet in southwest Riverside County, and ground water basins for later use.

The project will help lessen the impact on the delicate ecosystem of the Bay/Delta estuary by enabling Metropolitan to take water during high flows. Studies show that during high-flow periods, significant amounts of fresh water flow into the ocean through the San Francisco Bay.

With the completion of the Badlands dig, the Inland Feeder project stands nearly 70 percent complete. The two additional tunnels - each about five miles long - to be burrowed beneath the San Bernardino National Forest have been put out to bid, with construction expected to begin in early 2003.