New earthquake-resistant pipeline is a major upgrade for Alameda.
East Bay Municipal Utility District (EBMUD) has successfully completed the installation of a new earthquake-resistant pipeline–the Inner Harbor Crossing—below the Oakland Estuary floor to serve the City of Alameda. The new pipeline is a major infrastructure upgrade. Measuring approximately 3,000 feet in length and 32 inches in diameter, it replaces a cast iron pipeline dating back to the 1940s in an area that is susceptible to liquefaction during an earthquake.
EBMUD invested nearly a decade of work and partnerships to bring the project to fruition. Initial plans to replace the four water transmission lines that serve the City of Alameda with three new transmission lines were completed in 2014. An environmental impact report for the full project was completed in 2016, and the first crossing between Alice Street in Oakland to Webster Street in Alameda was prioritized using innovative horizontal directional drilling to drill a borehole beneath the Oakland Estuary floor near the Posey Tube. In 2022, EBMUD awarded a $25 million contract to Cratus Inc. to complete the project.
Construction crews used 63 sections of high-density polyethylene water transmission pipe fused together to construct the Inner Harbor Crossing. The material of the new pipe significantly increases flexibility and durability, improving system reliability during an earthquake. A bore hole was drilled 160 feet beneath the estuary, and the pipeline was installed over the April 7-8 weekend, stretching more than a half-mile along Mitchell Avenue in Alameda before it was pulled through the bore hole north of Estuary Park in Oakland.
“The pull of the new pipe under the estuary was a remarkable feat of engineering and construction,” said EBMUD Board Director Doug Linney. “This work will benefit the 76,000 residents of Alameda for decades to come with a more resilient and reliable water distribution pipeline. We are extremely grateful and proud of this effort, the crews who performed it, and our customers for their patience and support.”
The new pipeline is just one part of EBMUD’s efforts to upgrade and maintain its infrastructure. The organization is investing over $2.8 billion in the next five years to rehabilitate water treatment plants, pumping plants, reservoirs, pipelines, wastewater facilities, and sewer interceptors. Aging water and wastewater infrastructure across the EBMUD service area, some of it more than 100 years old, needs continued maintenance and replacement, the utility noted.
The District will install two miles of 24-inch steel pipeline to connect the new Inner Harbor Crossing to the district system in both Oakland and Alameda. Once the new transmission line is in service, district officials will determine whether the old cast-iron pipeline can be used as a recycled water line. Work on the second Alameda transmission replacement at Bay Farm Island will start in about five years, to be followed by a final crossing parallel to Park Street.
As EBMUD innovates to improve infrastructure and services, the utility must also confront rising costs due to supply chain disruptions and inflationary pressures on equipment, chemicals, energy, and labor. EBMUD is recognized as a responsible financial steward and is the only California water utility to receive Moody’s Investors Service’s highest Aaa water bond rating.