Bagnell Dam bridge work 'strictly a rehabilitation project', lanes will not be widened

Dan Field
Bagnell Dam.

The width of the driving lanes on the Bagnell Dam bridge road will not change as part of a $1.9 million rehabilitation project that will begin after Labor Day.

MoDOT announced recently that the road over the dam will undergo a significant upgrade after serving for more than 90 years as an entrance to Lake Ozark and the eastern side of Lake of the Ozarks. A public virtual meeting was hosted by MoDOT recently.

During a Question & Answer period, MoDOT officials said the 20.6-foot lanes would not be widened.

Project Engineer Ryan Libbert said that the existing aesthetics and aspects of the bridge, which was built in 1929, will not change. That includes the width of the lanes and the width of the sidewalks.

The bridge road is 2,853 feet long and lanes are 20.5 feet wide, plus a 36-inch sidewalk.

“It’s strictly a rehabilitation project,” he said.

Bridge rehab scope.

The project involves patching, repairing and maintenance of the bridge deck and adjoining sidewalk to give the bridge another 15-20 years of life before more work is needed. Much of the work includes bringing the bridge and sidewalk into compliance with the Americans With Disabilities Act (ADA). The purpose is to repair the bridge deck, expansion joints and barrier walls and to replace the bridge driving surface and repair the adjacent sidewalk.

“Getting a bridge of this scope to last 100 years is pretty impressive,” Libbert said during the virtual meeting.

MoDOT Area Engineer Bob Lynch noted that Bagnell Dam is included on the National Register of Historic Places and the road is as well because it is attached to the dam.

“As long as any structure meets the criteria of eligibility for the National Register listing, MoDOT is required to follow Section 106 of the National Historic Preservation Act,” Lynch explained.

Libbert said there is a limit on what can be done with rehabilitation, so the focus will be on issues that involve water saturation of concrete surfaces and structural integrity of the bridge.

The project includes:

•Repair existing expansion joints. There is an issue with bonding where the joints meet the concrete. Water is seeping under deck above dam. The plan is to remove and replace existing seals to keep water from going where it is supposed to.

•Patching. Partial or full-deck patching is planned for deteriorating areas of concrete. Info from electronic engineering scans will be used to determine where to patch. The existing surface will be milled off including the use of hydro demolition to remove weakened concrete. A thin overlay will be applied to raise deck less than an inch.

•Sidewalk and curb deterioration. A patching system similar to that used on the deck will be used on the sidewalk and curb to meet Americans With Disabilities Act standards.

“Changing the width of sidewalk is beyond the scope of the project,” Lippert said.

Some on social media have suggested that the sidewalks should be removed so the lanes can be widened. That can’t happen, Area Engineer Lynch explained.

“Removal of the sidewalk would be difficult for two reasons. First, due to the historical nature of the dam, and second, in general it is very difficult to remove an existing sidewalk facility that is used by pedestrians,” he said.

•Because the height of the concrete sidewalk railing does not meet ADA regulations, tubing will be installed on top of the existing rail to raise the height to 42 inches.

Bagnell Dam Bridge to receive $1.9 million rehabilitation in 2021

Bridge closure

After the Labor Day Weekend, the bridge will be closed to thru traffic until about Dec. 1. Traffic will be re-routed to Rt. 242 so motorists can have access to Bagnell Dam Blvd. and Horseshoe Bend Parkway. MoDOT officials say signage will be installed in appropriate locations to divert traffic.

The Bagnell Dam Bridge project and the new Highway 54 interchange now under construction should be finished about the same time.

MoDOT officials also noted that the type of traffic using the new Bagnell Dam road will not be limited. There had been some discussion that trucks would not be allowed to preserve the integrity of the road and because the road is narrow. Officials said the road is designed to handle all types of traffic.