A small but unresolved engineering question about the appropriate height for a boardwalk bridge over a controlled waterway delayed final bid documents, the Town of Southborough Trails Committee said April 24.

Kat McKee, the committee chair, said the structural engineer and the Massachusetts Water Authority (MWA) are debating how high the bridge should be relative to the 100-year flood level. McKee said the situation is unusual because MWA controls the flow of the water. "So it's really this is about liability," she said, adding the parties are seeking a design that meets flood standards without producing an awkwardly high bridge.

McKee said the engineer will finalize bid documents once the design question is resolved and that she expected an update by email the following week. The committee said, barring additional complications, it hoped to be ready to go to bid within a month; the committee also noted the bridge will be steel and that steel-price and Buy America considerations are factors in procurement.

No schedule or vendor decision has been finalized; the committee said it will provide a further update when the engineer delivers the revised bid documents.