Double tunnel vision

The famed tunnels on Kanan Dume Road, including the ones known as T3, above, are getting new liners.

It just might be the biggest production to hit the tunnels of Kanan Dume Road since 1,000 extras turned out for the 1998 action flick “Deep Impact.”

Two sets of tunnels on the famed, twisting road through the canyons above Malibu are about to get a multimillion dollar makeover.

The Board of Supervisors this week approved plans to install steel liners in the tunnels at an estimated construction cost of between $7 million and $9.5 million. When related services such as planning, testing, consulting and surveying are included, the project’s total cost is expected to be about $11.1 million, the Department of Public Works said in a letter to supervisors.

The reinforcement is needed to deal with decades-old gunite lining and steel ribbing that are beginning to show their age.

“We did some inspections and found that some of the existing liner was coming down,” said Lance Grindle, assistant head of Public Works’ Design Division. “I don’t think anybody got hit, but the potential was there.” Another problem: water seeps into the tunnels in rainy weather. A new drainage system will be installed as part of the project.

The interior of the tunnels will be reinforced with new steel liners.

Kanan Dume Road was dedicated in 1968, and at least two of its tunnels were in service by the following year. But completing the entire stretch from the Ventura Freeway to the Pacific Coast Highway was a long-running project. A 1965 Road Department memo said the highway (then known as Dume Canyon) was half-finished and would take six more years of inmate labor from the county’s now-defunct Detention Camps to complete the final six miles. (The same memo noted that the county got 70% of the right of way “gratis.” The rest of the land was valued at around $140,000.)

The work crews were followed by Hollywood crews, attracted by the look of tunnels set into craggy stone on a dramatic stretch of quintessential California roadway running from Agoura Hills to Malibu.

Over the years, perhaps you’ve caught the tunnels’ work in Chrysler or Mitsubishi commercials, or in movies like “Charlie’s Angels: Full Throttle.”

But their biggest star turn came in the final scenes of “Deep Impact,” in which they doubled as an Ark-like cave for residents of Planet Earth hunkering down in hopes of surviving a massive comet strike.

The two-day shoot included not just 1,000 human extras but also “lions, jaguars, hyenas, alligators, pythons, kangaroos, ostrich, buffalo, camels, elephants, zebras, cattle, chickens [and] birds,” according to the Film Scouts website.

Location scouts seeking to book the tunnels for upcoming appearances will need to work fast (as well as overcome a lot of county restrictions on vehicle size and weight.) The liner replacement work on the Kanan Dume tunnels known as T2 and T3 is expected to begin in September and conclude in August, 2013. After that, a separate project will target another pair of Kanan Dume tunnels, known as T1, as well as a single-barreled tunnel on Malibu Canyon Road.

For the Kanan Dume tunnels, work will take place on one side at a time, while the other side will temporarily be used for two-way traffic. Plans for handling traffic on Malibu Canyon during the eventual tunnel work there are still being developed to ensure that emergency vehicles will be able to get through and to determine whether some or all the work could take place at night.

The county had initially asked for bids on the tunnel work last year. But the original solicitation had to be amended several times, and when the bids came in, each of the four lowest bids had “some level of discrepancy, clerical error, omission, vagueness or mistake,” the Public Works letter said.

The new bids will be opened on April 10.

The tunnels' appearance was transformed for a starring role in the 1998 film "Deep Impact."

Posted 3/14/12