Lyndon Revises Covered Bridge Project To Address Flood Risks; Public Comment Reopens

Paul Hayes phayes@littletonrecord.com Staff Writer May 1, 2025

LYNDON — Plans to renovate Lyndon’s historic Sanborn Covered Bridge have been revised to reduce flood risks after last summer’s devastating storms. The new design aims to improve water flow and reduce flooding at the Route 5, 114, and 122 intersection.

The updated plans call for raising the bridge more than four feet, placing it above the 500-year flood level with an additional foot of freeboard. The project is intended to reduce the bridge’s impact on surrounding roads and infrastructure during major flood events.

The $2.2 million project is largely grant-funded. The Northern Borders Regional Commission, a key funder, announced this week that it supports the revised plans and will reopen public comments from May 3 to May 11. Comments can be submitted to nepa@nbrc.gov".

The redesign was requested by the town’s Hazard Mitigation Committee, which voted last August to preserve the bridge and requested changes to reduce flood impacts. That decision differed from a recommendation by consultants at SLR International, who advised removing the bridge entirely.

While the town did not follow SLR’s recommendation, engineers used the firm’s flood modeling data to inform the new design. According to NBRC, the hydraulic opening under the bridge will increase from nearly 1,000 to more than 1,400 square feet, allowing floodwaters to pass more freely and reducing the risk to nearby infrastructure.

“By improving floodwater passage beneath the bridge, the design reduces the risk of hazard to individuals and nearby infrastructure during flood events,” NBRC said in a statement.

The Sanborn Covered Bridge was severely damaged during a historic storm on July 11, when the swollen Passumpsic River bowed the bridge, broke one of its abutments, and nearly swept it downstream. The updated project would place the bridge one foot above the July flood levels and raise the structure from nine inches below to two feet above the 100-year flood elevation. The renovation includes structural repairs, rebuilt abutments, and other flood-mitigation improvements.

Once the public comment period closes and other bureaucratic hurdles are cleared, the design will be finalized, and the project will move to the bidding phase.

Built in 1869 on Centre Street and moved to its current location over the Passumpsic River in 1960, the Sanborn Covered Bridge was purchased by the town in 2022. Lyndon also acquired a two-acre parcel at the south abutment — future home to the planned Sanborn Covered Bridge Park — and a right of way connecting to Route 122 at the north end.