A 61-year-old bridge in the Harmony Hills subdivision off Vogel Road near Arnold will be replaced early next year.
Jefferson County Public Works Director Jason Jonas said the Harmony Hills bridge is one of 14 private development bridges under the care of the county through the street maintenance program.
The county will pay Gershenson Construction Co. Inc., based in Eureka, $987,799.70 to replace the bridge. Gershenson submitted the lowest of five bids for the construction of the bridge.
Seventy percent of the cost, or $691,459.79, will be covered by a federal grant, and the remaining 30 percent, or $296,339.91, will be covered by part of the county’s share of the 1/2-cent road and bridges sales tax.
The project includes replacing the structurally deficient bridge with a new bridge consisting of four concrete spread box beams, which will be protected with “rock blankets” to prevent erosion, according to county documents.
The work is expected to begin in January or February and be completed no later than Sept. 1, 2026, Jonas said. Gershenson has 120 working days, or about five months, to complete the project.
Vehicle traffic heading to the 50 or so homes beyond the bridge will be reduced to one lane during construction, with the traffic switching to the opposite lane halfway through the project so that construction workers can work to replace both sides of the bridge.
“This bridge has a load posting rating of 15 tons and has a substructure condition of poor rating, which is not good,” Jonas said. “Usually, the classification for grant funding for full replacement is ‘poor.’ The new bridge won’t have a load posting – so 60 tons or more will be its load rating.”
County help
Jonas said most homeowners would not be able to afford to replace their subdivision’s failing bridges on their own. The Public Works Department can apply for larger grants to cover the construction costs.
“This is the third private development bridge replacement, and we don’t have any more (in the works),” Jonas said. “We’ve taken over 14 bridges in private developments, but none of the remaining 11 have any grants for replacement; their ratings are good enough that there’s no immediate need for major repairs and replacement.”
Most recently, the county replaced a crumbling bridge on Commerce Drive that connects more than 100 homes in the Willow Trace and Sierra Vista neighborhoods and several businesses to the West Outer Road near Arnold. The project cost $989,410.60, but a federal grant paid for 80 percent, or $791,528.48, of the cost to replace the bridge. Public Works had accepted the subdivisions in its street maintenance program in 2020.
Under the program, once a street or series of streets is approved, the county’s Highway Division assumes responsibility for maintaining and repairing those roads. Additionally, the county takes care of snow removal and weather treatment on the roads.
More than 100 subdivisions have been accepted into the program since its inception in 2018.
Jonas said Public Works puts a high emphasis on taking over private bridges when judging whether a subdivision should be accepted into the maintenance program.
To be eligible for the federal grant, the county must own and maintain the street up to and including the bridge that needs to be replaced, he said.
In the case of Harmony Hills, Public Works negotiated the transfer of ownership of Harmony Hills Drive, from Vogel Road to Cord Circle, to include the dilapidated bridge. The county will “forevermore” own and maintain that portion of Harmony Hills Drive, Jonas said.
“To get the grant funding, we have to wind up owning (the road) at the end of it,” he said. “Bridges get a high level of interest from the county because we really don’t want a lot of private bridges. There’s a high cost in replacing them. There’s no way a 75-100 home subdivision is ever going to be able to afford that. All the county has to afford is 30 percent of it; if (a subdivision) were to maintain (a bridge) privately, they would be 100 percent on the hook, with property owners who couldn’t possibly afford it.”