Perris Valley Pipeline Turns South

Sept. 28, 2010

Population growth, new housing and industrial construction, plus drought conditions all played a part in conceiving and planning this crucial $multimillion infrastructure project.

Population growth, new housing and industrial construction, plus drought conditions all played a part in conceiving and planning this crucial $multimillion infrastructure project.

Project Fast Facts:

The Metropolitan Water District of Southern California, Western Municipal Water District and Eastern Municipal Water District are developing a $110-million water project jointly. When completed, the pipeline will increase the treated water delivery capacity in Eastern and Western's service areas by some 150 million gallons per day.

The entire Perris Valley Pipeline will consist of 6.5 miles of 96-inch pipeline from Metropolitan's Henry J. Mills Water Treatment Plant, east along Alessandro Boulevard and then south paralleling the 215 Freeway. EMWD is constructing a separate 4-foot-diameter, 2.5-mile-long water pipeline that will connect its service area to the Perris Valley Pipeline at Cactus Avenue. An additional 3.1 miles of pipelines ranging in diameter between 36-inch and 60-inch are under construction along Oleander Street, which will connect to the Perris Valley Pipeline south reach at Western Way.


Early Phase Nearly Completed

MWD's Perris Valley Pipeline North Reach segment is a 2.7-mile placement of 96-inch- and 109-inch-diameter water pipelines, part of an ongoing water delivery system upgrade involving the separate Southern California water districts.

Multiple Construction Challenges

Wes Brodeur — project manager with W.A. Rasic Construction (WAR), the contractor on the North Reach — has said work along this route was burdened, "... with unstable ground in certain areas; deep excavation ...traffic control is a big issue as Alessandro Boulevard is a major artery to and from I-215 to Riverside and Orange/L.A. Counties; high ground water table; hard rock formations requiring rock drilling and excavation."

The 9,000 linear feet of pipeline along Alessandro Boulevard, tying into the Mills Plant piping, used conventional excavation with a series of steel shoring cages. Trench shields were custom made 12-inch-thick steel cages 50 feet by 10 feet by 8 feet wide. Excavation depths along Alessandro Boulevard averaged 20 to 26 feet, according to Brodeur.

Work on the North Reach started in September 2007. The pipeline is scheduled to be functional in early 2009. A crew of up to 70 employees worked 10-hour days, including every other Saturday, to keep on the work on schedule. Final touches will include street improvements, retaining walls, etc.


Rasic constructed a 100-foot tunnel at a 30-foot depth where the Mills Plant tied into the Alessandro East connection to avoid overhead high power lines, and buried utility lines that would have cut power to entire neighborhoods and thousands of people if interrupted during construction.

Two other tunnels were built about 9,000 feet to the east. One is 450 feet in length, the other is 500 feet.

At the east connection, a 50-foot-deep tunnel access portal was constructed. One tunnel goes east under a flood control channel and railroad tracks. The other goes northwest under Alessandro Boulevard, tying into the excavation there. Brodeur said this portal required blasting and off-hauling of some 5,000 cubic yards of rock that was then broken down as class II base.

Turning To The South

Perris Valley Pipeline's next phase — The South Reach — began in September 2008 and should be completed in early 2010, according to Tom Campbell, MWD project manager:

"The Pipe is welded steel with Type B dielectric coating. The majority of pipe will be field lined, though some will have shop lining. Nominal diameter is 96-inch. Pipe is being supplied by Northwest Pipe Company under a separate contract," Campbell said.

Some 20,313 linear feet will be laid in the South Reach, although a little over 1,000 linear feet has so far been placed, at various depths, with a 10-foot minimum, he added. There will also be a tunnel bored beneath I-215 freeway. Tunneling has not yet started. The pipe installation contractor is Oscar Renda Contracting, Inc., of Roanoke, TX.

EMWD's Work In Progress

Eastern Municipal Water District's connection work is well under way, according to Betty Gibbel, public affairs officer for EMWD.

"We are currently laying the transmission pipes on Oleander Street, south of March Air Reserve Base. We are anticipating a completion date of November 2009.

"Our contractor is Trautwein Construction of Riverside. We pre-purchased EMWD's pipe competitively for this portion work at $4.6 million. The contract with Trautwein is for $6.5 million."

A separate contract will be competitively bid for construction of EMWD's Western Way Pump Station. EMWD will also be constructing a temporary gravity bypass to deliver water from the MWD line — about 50 cubic feet per second (CFS). When the booster station is completed in two years, EMWD will draw 145 CFS.