Any plans to replace the decaying Garnett Creek Bridge on Highway 29 are on hold in the face of budget constraints and opposition from Calistoga residents, Caltrans officials said this week.
“Right now we’re not even at the starting point; really we don’t even have a project,” Principal Transportation Engineer Doanh Nguyen told residents at a crowded meeting Tuesday organized by county Supervisor Diane Dillon.
The bridge, between Calistoga city limits and Tubbs Lane, was built in 1902 and is one of a dwindling number of examples of stone arch bridges built in Napa County in that period. It is a well-known landmark and is on the National Register of Historic Places.
Caltrans caused a stir late last year, however, with a preliminary study that suggested that the bridge should be replaced. The agency said the bridge would either need to be demolished to make way for a new one or else preserved by rerouting the highway about 80 feet downstream to a new span.
Either option would be controversial. Preservationists don’t want to see the historic structure demolished, but nearby landowners and agriculture groups don’t want to see the state converting any of Napa Valley’s iconic vineyards into new roadways.
“The bottom line is that vineyard land should not be touched,” Dillon said.
Residents at the meeting complained that Caltrans had surprised them with talk of replacing the bridge. Landowner Michael Savage said he was astounded to hear even speculative talk of using his adjacent vineyards for a new roadway.
“It may be a hypothetical plan, but it annihilated the value of our property overnight,” he said.
Other residents suggested less drastic options, such as measures to control the speed along that section of the highway, improving signage to warn of the narrow bridge or reconfiguring the creek bed to reduce the speed and power of water flowing through.
The Caltrans officials at the meeting promised to consider the local comments and try to work out a process to come to an acceptable compromise before the bridge becomes unsafe to use. Dillon said she would help coordinate such a discussion.
Nguyen said the agency asked the state for money this year to do a more thorough assessment of the bridge and its future, but the request was turned down because of a lack of money.
The next opportunity to ask for money would be in 2014, he said, but the swell of community opposition to the preliminary plans means the agency has shelved the issue for the moment.
“Right now we have no plans,” he said. “It’s on the watch list and we’ll watch it closely over the winter” to see if the creek does more damage during the rainy season.
Doing nothing with the bridge is risky, Caltrans says, since the bridge is perilously close to the bottom of the scale in terms of safety and structural integrity. On the 9-point scale the agency uses, a new bridge in perfect condition would rate a 9, while a bridge that scored a 1 would be judged to be an immediate threat to public safety and would be closed.
The Garnett Creek Bridge now rates a 3, Nguyen said, largely because the stream has been steadily eroding the pillars and foundation, and heavy modern trucks are causing cracking.
The bridge is also dangerously narrow by modern standards: just 19 feet wide, too narrow to safely accommodate two full-sized trucks at highway speeds. Trucks account for about 9 percent of the 4,000 vehicles that use the bridge daily, an unusually heavy concentration of big vehicles that is putting enormous strain on the structure.
The option of rerouting Highway 29 up Foothill Boulevard and across Tubbs Lane is not impossible, Caltrans says, but would require expensive upgrades to Tubbs Lane before the state could accept it as a new highway route.