Many people drive down Crosby Lane in Brewster for the town beach and the adjacent, mile-long state beachfront, or to view and visit Tawasentha, the historic home of Albert Crosby.

But there’s also an extensive salt marsh, one that’s severely constricted by a clogged, 12-inch culvert under Crosby Lane.

Permits are now in place to replace that culvert and to restore flow to the upper portion of the marsh. The much smaller marsh on the western side of Crosby Lane now hosts freshwater species like phragmites (common reed grass) and the very invasive purple loosestrife.

The town received $66,966 for design and engineering by the Horsley Witten Group from the state Department of Environmental Protection in 2016 with the help of the Cape Cod Conservation District . That’ll take the project to the 75-percent engineered stage.

“What precipitated the project was we were going to resurface Crosby Lane and we noticed there was a culvert there,” explained DPW Director Patrick Ellis.

He worked with Natural Resources Director Chris Miller to secure the grant. The culvert had essentially collapsed and the upper marsh wasn’t draining.

“We knew there’d be a box culvert and we’d have to raise the roadway and also treat the stormwater,′ Ellis said.

During extra high tides the lower portion of the road floods and the beach is cut off. Raising the road will maintain access. The current culvert is only about 12 inches in diameter. The new box culvert will be five feet, greatly increasing the flow. The incoming salt water will eliminate the invasive loosestrife and phragmites.

Brewster is now hoping for further funding for construction. It is pursuing DEP grants to cover the estimated $340,000 cost. Ellis said the town expects to hear on the first application around Sept. 1. That grant is unlikely to cover the full cost so it will pursue more funding. As a result construction wouldn’t start until next spring although Brewster is ready to seek bids.

“Obviously we’ll do it during a slow time for the beach,” Ellis noted.