Tunneling nearly complete for Inland Empire water project

In its two decades, the project has faced fire, flood, regulatory disputes, difficult geology, grouting problems, earthquake considerations, a switch of contractors and more. At one point it was $100 million over budget.

The boss at the Metropolitan Water District of Southern California jokes that the project suffered everything but a plague of locusts.

Still, the agency insisted it needed a higher-capacity system to bring water from Northern California to its massive reservoir, Diamond Valley Lake, outside Hemet.

A new project manager was brought in three years ago with a simple command: Failure is not an option.

And today, several years behind the original schedule, the $1.2-billion project will complete its last bit of tunneling: a four-mile stretch known as the Arrowhead West Tunnel in the San Bernardino Mountains.

Officials will cheer as an 820-ton, 450-foot tunnel boring machine punches through at Devil Canyon, near Cal State San Bernardino, where the California Aqueduct will eventually connect.

Then it's all downhill, literally. Set for completion in 2010, the 44-mile route includes 16 miles of tunneling in three sections and 28 miles of underground piping that will empty into an already built canal. From there, it will travel 10 miles to Diamond Valley. The idea is this: In the future, water will arrive from the California Aqueduct in fast bursts due to climate change and shifting snow patterns. The smooth, faucet-like flow will become more like blasts from a fire hose.

The current plumbing of the water district system is considered inadequate to capture the volume in such flows for storage. Enter the Inland Feeder, whose engineering is widely admired.

"We'll come up with something better" for a name, water district General Manager Jeff Kightlinger said Monday as he talked to reporters about the promise and the problems of the project.

"We knew it would be tricky," he said. "It was trickier that we thought."

The Arrowhead West Tunnel, between Waterman and Devil canyons, may have been the trickiest.

In 2003, the wildfires that swept through much of Southern California roared over the Waterman construction site, scorching everything in their path. Three months later, a fast-moving mudslide plugged the front of the tunnel with 16 feet of mud and water. Work stopped for months.