Contractors repairing Lambert’s Cove Road at Smith Brook in Tisbury have discovered another sinkhole under the roadway, which has been closed to traffic since Dec. 15 following the discovery and temporary repair of a sinkhole and washout Dec. 10.

Luciano’s Excavation Inc. of Taunton brought heavy equipment, pumps and material from the mainland Thursday and began work in the late afternoon, according to an update from town administrator Jay Grande. The culvert carrying Smith Brook beneath the roadway is blocked and believed to have collapsed, Mr. Grande notified the Gazette Friday.

“The existing culvert is to a depth of approximately 10 feet below the road surface,” he wrote in an email.

“The groundwater level is just four to six feet below the road surface at this time and needs to drop further before the contractor can uncover the existing culvert and make repairs and replace the culvert and headwall at Smith Brook.”

Luciano’s has installed pumps that are reducing the water level, Mr. Grande said.

The Tisbury portion of Lambert’s Cove Road remains closed until the drainage construction work is completed, which Mr. Grande said is expected to be just after the first of the year.