County officials say the small bridges, used to navigate over a gutter-like dip separating residents' property from the trail, are a safety issue and liability for the county.
Many of the footbridges stretch over the three-foot wide, two-foot deep ditches and are poorly constructed, said John Pulliam, who manages the trail through county public works.
This creates potential flooding problems and unnecessary injury and risk, he said. If someone falls on one, the county would be responsible.
"Some of those people have had bridges out there 10-plus years... No one inspects them and some are rotting," Pulliam said.
Fifty to 60 footbridges were tagged in Alamo and Danville last Friday and all must be removed by Dec. 7. If they aren't taken away by that date, public works will dispose of the footbridges and charge owners the fee.
Residents aren't happy. They say removing the bridges are an unnecessary inconvenience and that there's no real hazard in the first place.
"I think they are being a little bit overzealous. The ones built properly should be granted a permit. There's no way anyone is going to trip on it," said Bob Myhre, an Alamo resident who lives along the trail.
Officials, however, explained that even well-constructed bridges can cause clogging from branches and eventually flooding.
"During a rainstorm, debris could get caught," said Chris Lau, county civil engineer.
With no footbridges, neighbors would either have to enter the trail at a cross street, climb down into the gutter, or jump across. During the winter and spring months, the gutter collects rain and is often damp.
Walkers on the trail Monday afternoon said the encroachment crackdown wouldn't affect them or their use of the trail. They noted they had never seen the gutters full of rainwater.
"I've lived here 22 years and I've never seen it flood ... It's ridiculous," Myhre said.
He said he removed his footbridge over the weekend.
Since the county began an effort to remove illegal encroachments in April 2006, the number of footbridges in Alamo and Danville has increased by about 10.
"It's harder for crews to go out there and clean," Pulliam said.
The Iron Horse Corridor is the county right of way and most violations are happening in Alamo and Danville, where the trail runs through residential neighborhoods. The most rural part of the trail is in these two communities.
Pulliam said he's gotten mixed feedback from residents about the effort. One trail user said he understood the county responsibility to do the cleanup and another called him and left an angry voicemail.
Other encroachments can include benches, statues and other items, but for now, the county is focusing on the footbridges. The county is not targeting encroaching fences as part of the crackdown.
To gain an encroachment permit, call John Pulliam at 313-2165. Permits are granted for homeowners for landscaping and utilities. Footbridges cannot receive permits.