Collapsed California bridge earned 'A' rating just last year

Brett Kelman, Colin Atagi, Jesse Marx, Sammy Roth | The (Palm Springs, Calif.) Desert Sun

Show Caption Hide Caption Collapsed California bridge given an A rating last year A remote bridge in Desert Center, California that collapsed during heavy rain was given an A rating just last year. The 48-year-old bridge also had one of the highest possible flood safety ratings; it should have withstood even the heaviest rainfall.

A 48-year-old bridge that collapsed Sunday in a rain-swollen California desert earned an "A" rating just last year, federal records show.

Inspectors gave the eastbound portion of the Tex Wash Bridge a "sufficiency rating" of 91.5 out of 100, according to the Federal Highway Administration. The bridge also had one of the highest possible flood safety ratings, which means it should have withstood even the heaviest rainfall.

And then, on Sunday, more than 5 inches of rain fell in the open desert east of the Coachella Valley. Rushing water flooded into the wash beneath the bridge and ate away at the dirt around the foundations. Eventually, one end of the eastbound lanes cracked free of the highway and tumbled to the desert floor, cutting the primary route between Arizona and Southern California.

Built in 1967, the Tex Wash Bridge sits on Interstate 10, linking Los Angeles to Phoenix. Located just east of Palm Springs, Calif., the bridge is owned and maintained by the California Department of Transportation, or CalTrans. Officials there said they were investigating how a highly rated bridge managed to fail so spectacularly.

An average of more than 20,000 cars per day pass through the area, according to federal highway statistics. Traffic was rerouted to give motorists options around the crucial arterial link.

The California Department of Transportation said Monday it will attempt to re-open I-10 by diverting all traffic onto the westbound portion of the bridge, which did not collapse. However, engineers must first verify that the westbound lanes are undamaged, so it is unclear when the road will re-open.

The agency will also investigate how a highly-rated bridge was susceptible to collapse. The Federal Highway Administration had contacted CalTrans with similar questions, CalTrans official Philip Havins said.

It's possible the bridge collapse was triggered by the eastern bank of the Tex Wash shifting further east, leaving the bridge foundation unstable, said John Hunt, an expert at Ayres Associates, an engineering consulting firm.

Hunt said this phenomenon is known as "channel migration," and it's not easy for bridge inspectors to see coming.

"It's not all that unusual for that kind of thing to happen at a bridge that got a low risk rating," Hunt said. "It could very well be that it all happened with this one flood, that there was no earlier sign of anything going on."

The Tex wash collapse is the most disruptive incident of this kind in the recent memory of Riverside County, but it did not happen at the county's worst bridge. During annual inspections, dozens of other bridges have scored worse than the Tex Wash bridge, raising questions about when — and where — this might happen again.

EL NINO RISKS

The risk could be evening higher considering forecasts of a strong El Nino, which is expected to bring more frequent, more powerful storms to Southern California this winter.

In Riverside County alone, 45 other I-10 bridges received lower ratings than the Tex Wash Bridge, and 39 of those bridges are older. Eight I-10 bridges, including the Tex Wash Bridge, have been deemed "functionally obsolete," which means they are either too small or poorly suited for modern-day traffic.

Two more I-10 bridges — which span 44th Avenue in Indio, Calif. and the Pacific Crest Trail in Whitewater —have known structural deficiencies.

Beyond the I-10 route, bridge inspectors found 119 obsolete bridges and 79 structurally deficient bridges in Riverside County, a 7,303-square-mile swath that stretches from just east of Los Angeles to the Arizona border, according to 2014 data from the Federal Highway Administration.

In the wake of the Tex Wash collapse, politicians on both sides of the aisle said the incident is emblematic of a much larger problem – California's crumbling infrastructure. Leaders agree the state needs to spend billions to repair roads and bridges, but they disagree as to where the money should come from.

Gov. Jerry Brown, a Democrat, has proposed raising the state's excise fuel tax to raise more money for infrastructure.

State Senate Republicans, meanwhile, are pushing legislation that would require transportation taxes to be used exclusively on transportation projects. State Sen. Jeff Stone, a Republican who represents the Coachella Valley, pointed to money raised by Proposition 42, which was meant for transportation projects but was moved into the general fund by lawmakers.

"They circumvented the will of the citizens of California and diverted billions of dollars," Stone said.

U.S. Sen. Barbara Boxer issued a statement pushing for bi-partisan support for The Drive Act, a bill she introduced last month to funnel more federal transportation funding to local and regional agencies.

"How many more bridges have to collapse before we come together and pass a 6-year, robust transportation bill?" Boxer said.

EMPTY INTERSTATE

After the Tex Wash collapse, CalTrans closed I-10 from Route 86 to the Arizona state line, leaving about 100 miles of empty highway sprawling through the open desert. The roadway — which normally sees more than 27,000 motorists per day — had none.

Generally, detoured motorists could head north, using State Route 177, Highway 62 and Arizona route 95, or head south, using Highway 111 and Interstate 8. Increased traffic was reported on both detours.

County Supervisor John Benoit, who toured the bridge scene on Monday morning, said the business impacts of the collapse would be far-reaching.

Interstate 10 is a major thoroughfare for the agricultural market, with even just one company sending as many as 40 trucks over the bridge each day, Benoit said. Detours could add 90 minutes to each trip.

Ramifications of the bridge closure were especially potent in Blythe, a small town near the Arizona border that is heavily dependent on motorist pit stops and lunch breaks. Detoured motorists poured into Blythe on Sunday evening, causing gas and grocery sales to skyrocket, but the town was empty by midday Monday, according to interviews with several store owners.

"They hunkered down last night, and hit the road this morning," said Tom Weiss, owner of Blythe's Rebel BBQ. "We're usually busy at noon, but it's dead now."

Reporter Brett Kelman can be reached by phone at (760) 778-4642, by email at brett.kelman@desertsun.com, or on Twitter @TDSbrettkelman.

Contributing: Xochitl Pena, Emily Donovan, Robert Hopwood, The (Palm Springs, Calif.) Desert Sun; Greg Toppo, USA TODAY