September 2, 2008
Water Project Expects Disaster
By Andrew Edwards
A costly 44-mile pipeline project designed to help carry water from Northern to Southern California will probably break one day.That's not a surprise. The Inland Feeder Project, recently given a share of the spotlight when a technological beast called a tunnel- boring machine breached the surface in Devil Canyon near Cal State San Bernardino, is a major endeavor.
But the project, still a work in progress, isn't invulnerable to the San Andreas Fault. No engineer nor scientist has yet figured out how to stop plate tectonics.
Instead those charged with building big projects like Inland Feeder have to figure out how to deal with natural disasters. John V. Bednarski is an engineering manager for Metropolitan Water District, the agency building Inland Feeder, and he has no illusions that the "Big One" will leave the project unscathed.
"The earth could actually move and shear the pipe as much as six feet," Bednarski said.
That means Bednarski and the MWD had to plan on what's going to happen when seismic forces give Inland Feeder a beating.
MWD officials say the pipeline is designed to allow spilled waters to flow into existing flood-control channels. That's important north of Highland, where the pipeline emerges from a tunnel below the San Bernardino Mountains at what the MWD calls the "City Creek Portal."
During an earthquake on the San Andreas, the pipeline could rupture near City Creek. Bednarski said the project is designed so spilled water flows through City Creek toward the Santa Ana River.
The City Creek bed courses through Highland, and the waterway was inundated with floodwater during the 2003 storms that followed the Old Fire.
MWD officials say the amount of water that would flow through City Creek after an earthquake would not equal the amount of water that would surge through the waterway during a major storm.
"We're not talking about a major amount of water that would discharge into the creek," said Jay Arabashi, an assistant program manager in MWD's engineering section.
Inland Feeder is a 44-mile, $1.2 billion project intended to carry State Water Project supplies from the Lake Silverwood area to Diamond Valley Lake near Hemet.
Near San Bernardino, two tunnels were dug through the San Bernardino Mountains along the project's path. A 5.8-mile tunnel called Arrowhead East, dug from Strawberry Canyon to the City Creek area, was completed in May. That's the tunnel that crosses San Andreas near City Creek.
Digging of the 3.8-mile Arrowhead West tunnel finished Aug. 20 to much fanfare. That tunnel crosses the San Andreas and Arrowhead Springs faults near its western end in the Devil Canyon area.
MWD spokesman Tim Skrove said flood-control washes near Cal State San Bernardino are expected to take care of spilled waters if the pipeline fails in that section.
"It's all headed to the Santa Ana River eventually," Skrove said.
Bednarski said there's less concern for major damage where the tunnelled stretches of Inland Feeder cross fault lines.
"It's probably safer inside the mountain," he said. "There's actually less chance of movement."
But the faults did create problems during the digging. In Arrowhead West, the tunneling machine sunk in weak rocks inside the fault zones. Mining crews had to build concrete and steel pads ahead of the digger's path to prevent the machine from falling off course.
Skrove said that whenever the dreaded San Andreas earthquake happens, MWD has machines in La Verne that make steel plates for repairs. That way, MWD won't have to try to bring in supplies on damaged transportation networks.
Skrove didn't want to guess how long it could take to repair Inland Feeder after a big earthquake because that's not the only water-supply system that could be torn to pieces.
"We could have hundreds of miles of pipes that are damaged," he said.
Earthquakes aren't the only problem for Inland Feeder. San Bernardino and MWD officials have not reached an agreement on how to solve the problems posed by the water supplier's plans to roll trucks weighing nearly 95 tons when carrying pipeline segments through San Bernardino.
City Attorney James F. Penman said the City Council is set to have a closed-door discussion on the issue today. He said the talks can be held out of the public eye because of the possibility of litigation.
(c) 2008 Inland Valley Daily Bulletin. Provided by ProQuest LLC. All rights Reserved.