Delta Tunnel Planners Should Learn From Seattle s Expensive Goof

Just inside the expensively delayed Alaskan Way Viaduct Tunnel | Photo: WSDOT

Commentary: Engineers will converge in Los Angeles from November 6-9, during the election, for the Cutting Edge 2016: Advances in Tunneling Technology conference. California, it seems, is a hotspot for industrial tunneling these days.

International tunneling firms will wine-and-dine political leaders in hopes of landing extremely profitable contracts, like the proposed Delta tunnels, while Californians are fixated on the elections.

So before the conference begins, let's review some recent West Coast tunnel history.

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Seattle's Big Dig vs. the Delta Tunnels

The Alaskan Way Viaduct (Highway) replacement tunnel project in Seattle and the proposed Delta tunnels in California have some interesting parallels.

But one thing the two projects don't have in common is length. The Seattle Tunnel, a single tunnel, will eventually be just 1.7 miles long. The proposed twin Delta Tunnels would be 35 miles long, for a total of 70 tunnel miles.

The Alaskan Way Viaduct replacement tunnel will be a single, deep-bore tunnel that will contain two levels of traffic with a massive diameter of 57.5 feet.

The proposed Delta tunnels are pressurized water tunnels, each 44 feet in diameter with 6-foot-thick walls, which will require a boring diameter of 52 feet, making each Delta Tunnel similar in size to the Seattle Tunnel.

The seismically unsafe Alaskan Way Viaduct in Downtown Seattle, due to be replaced once the tunnel gets dug. | Photo: lakewentworth, some rights reserved

Political Opposition

Both the Seattle and Delta tunnel projects were born out of political controversy.Voters rejected the Seattle tunnel project in 2007. Rural and suburban legislators had no appetite to pay for a risky tunnel venture in Seattle. This opposition led to the creation of a public-private partnership. If the tunnel ran over budget, the bill read, extra costs would be borne by property owners in the Seattle area who benefit from the tunnel.

The 1.7-mile Alaskan Way replacement tunnel is beset by delays and cost overruns...

In 2011, Seattle voters did eventually grant authority to the Seattle City Council to proceed with the tunnel contracts; however, there have been years of regret and frustration for area residents due to cost overruns.

In 1982, California voters rejected the Peripheral Canal, a project that would have served the same basic function as the proposed Delta tunnels, taking water from the northern Delta and sending it via the State and Federal water projects to big agricultural interests in the San Joaquin Valley and Southland water users. Californians may never get a second vote on the Delta tunnels proposal. Tunnel supporters, including Governor Jerry Brown, have outright ignored the initiative vote on the Peripheral Canal.

Funding Issues

The original Seattle Tunnel Project was estimated to cost $4.25 billion, with $2.8 billion coming from the state and federal governments to cover tunnel boring, a new highway interchange, and an above ground park. (The Delta Tunnels would have a much higher cost, starting at $17 billion before interest, operation expenses, and cost overruns that are likely due to the challenges of constructing two water tunnels, side-by-side, in soft soil.)

The Washington State Department of Transportation awarded a $1.4 billion design-build contract to Seattle Tunnel Partners (STP), a joint venture between Tutor Perini, a California-based construction company and Dragados, a Spanish company. When the STP public-private partnership was formed, state taxpayers were only supposed to contribute the $1.4 billion for initial construction costs. Cost overruns and delays were to be paid by the private partners.

Project Delays

STP had an $80 million tunnel-boring machine nicknamed Bertha built especially for the Seattle tunnel project. Bertha began digging on July 30, 2013.

... and the Delta tunnels would be far more ambitious. Seattle map inset to scale, upper right. Maps: public domain.

In December 2013, Bertha hit a metal pipe and overheated. The machine could not move backwards for repairs because it had laid a concrete wall behind it. Bertha had to be dug out of the ground, taken apart, repaired, and reassembled. That process took two years. The 1.7-mile, four-lane tunnel was originally supposed to open to drivers by the end of 2015. The project's new proposed completion date is early 2019.

Responsibility for Bertha's two-year delay is now before the courts. The contractor claims the state did not warn them of the metal pipe. STP filed claims of more than $200 million. Who will pay the final costs may not be known for years. If STP wins this case, state taxpayers will pay these costs.

In July 2016, Washington taxpayers were told they will also be on the hook for another $223 million in costs to keep staff and engineers engaged until 2019. Gasoline taxes, tolls, fees, or perhaps more transportation-fund debt would pay for those costs.

Public-Private Partnerships

The Seattle Tunnel Project public-private partnership has required hundreds of millions of dollars of additional public investment due to Bertha's breakdowns.

The Delta tunnels project, with the creation of a Joint Powers Authority, is poised to experience many of the same financial problems related to construction challenges. With water districts that cannot afford the tunnels participating in the JPA, taxpayers and ratepayers (especially in Southern California) could end up paying settlements with contractors for overruns and delays, just like the taxpayers of Washington.

More on the Bay and Delta

When Salmon Speak: The Winnemem Wintu and the Winter-Run Chinook

State Finally Admits Its Rivers Flow Downhill From Mountains

New Sea Level Rise Study Calls Delta Tunnels Into Doubt

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