Over the past 100 years, Allens Pond has remained a pond — as opposed to a mosquito-ridden puddle — thanks to a little human intervention.

Quick dredging work on March 28 restored a vital channel connecting the saltwater pond to Buzzards Bay. The dredging occurs about every five years, but only the fix only takes a few hours of excavating and bulldozing, explained Allens Pond Wildlife Sanctuary Director Gina Purtell.

The blockage between the two water bodies is caused by sand deposits, brought in by currents. They slow water flow to a trickle and seal the channel, explained Purtell.

“It’s beneficial for the pond to drain at the right rate. If it fills up like a bathtub, it affects everything around it,” explained Purtell.

Closure spells trouble for wildlife — including piping plovers, osprey, reptiles, amphibians, and fish — that rely on the unique estuarine environment. Mosquitos, however, thrive once the channel closes and the pond becomes stagnant, Purtell said.

The regular dredging of Allens Pond dates back more than 100 years, although the responsibility has shifted hands a few times. Purtell said that at one point, the town managed it, then local property owners took it on. Now, Mass Audubon works with property owners and state and federal agencies to conduct the dredging as part of a federally-approved beach management plan.

“What we don’t know now is how sea level rise will affect this in the long term,” Purtell said.

She explained that while the process is now a consistent, five-year cycle, she's heard from people familiar with the older dredging operations that the cycle used to be longer.