Trancas Creek Bridge replacement project plagued with delays

There were some engineering miscalculations, but at least the construction site was ready for rain

Just like most big construction projects, the bridge replacement at Trancas Creek and Pacific Coast Highway has had its share of setbacks since breaking ground last March. 

The existing 96-year-old, 85-foot-wide, 90-foot-long concrete bridge, constructed in 1927, is being replaced with a new concrete bridge 105 feet wide by 240 feet long. It will have two 12-foot traffic lanes, bike lanes, separate pedestrian lanes and 10-foot shoulders on both sides. North- and southbound traffic will be separated by a 6-foot median. Completion was originally scheduled for summer 2024.

Just last week, concerns were raised at the Public Safety Commission meeting about whether the construction site was prepared for the deluge of rain that was predicted. 

Memories of the torrent that occurred in that creek in a 2018-19 downpour were still fresh.

Commissioner Josh Spiegel expressed concern that piles of bridge construction materials and equipment would end up washing into the ocean or damaging the existing bridge if another flood occurred.

Hans Laetz, who lives near the construction site and has been frequently reporting on it for KBUU News, said in a phone interview that the construction crews had indeed cleaned up the creek bed in advance of the current storms. 

“The California Department of Fish & Wildlife extended the permit until Jan. 31. They have finished protecting the abutment with a pile of rocks, and finished their concrete work in the creek bed. Everything is out of the creek bed, and it looks shipshape,” he said. ”One section of plastic orange fence broke off and is dangling, but it’s probably not going anywhere.”

The Trancas Bridge Replacement Project as of Jan. 6 is located near Trancas Country Market. According to the City of Malibu’s website, after the end of October, there will be minimal construction activity, as the project permit does not allow work in the creek area between Nov. 1 and May 1. The original project completion date of early 2024 could potentially be delayed to early 2025. Photo by Samantha Bravo/TMT.

“There’s a bunch of stuff in the flood plain, but it’s heavy girders that aren’t going anywhere. There are some wood forms there, but they plan to use them next week. Three sets of vertical pilings and the header are all done. A crossbeam that connects the pilings is done. The bridge and the abutment are holding,” Laetz continued. “They’re waiting until better weather to connect the rest of the pilings.”

He explained that when KBUU news reported in mid-October that there was a lot of material and equipment remaining in the creek bed for rainy season, “There was a big flurry of activity” to get everything out of the creek bed to comply with a permit.

When it comes to the possibility of flooding, Laetz pointed out that the level of sand on Zuma Beach near the bridge is three to four feet lower now than it was when the creek flooded in 2018. 

“The beach is still as wide, but it’s not as high,” therefore there’s less chance of overflow.  In addition, lower sand levels have exposed some of the nearby culverts that funnel water under PCH, and are doing a good job of draining the highway.

Prior to October, delays had been caused when “the state discovered a previously unknown communications cable under the old Trancas Bridge,” according to KBUU News. This resulted in some preliminary work involving fiber optic line relocation work by a contractor for Frontier Communications.

Another delay was caused by a major engineering design flaw. On Oct. 21, KBUU News reported that the support casings for the bridge weren’t deep enough. At 68 feet down, the crew still hadn’t hit solid rock. When Caltrans stress-tested the new piling casings, they failed. They then decided to sink the big pipes twice as deep — down to 136 feet.

KBUU learned this by talking to construction workers about why the deck obviously wasn’t going to be finished and ready for traffic by mid-November, as called for by the original timetable. 

The problem turned out to be, based on KBUU’s observations, that test borings were done east and west of the creek, but not in the creek. Sources close to the construction project confirmed that.

The state would only acknowledge that the Trancas Creek Project was severely behind schedule, and that Caltrans was asking Fish & Wildlife for an extension to work past the Nov. 15 blackout date, which they received.

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