A local official called it the toughest decision he had had to make in three decades, one that East Goshen Township, Chester County, has been confronting for several years.

Tuesday night, the board of supervisors voted to breach the town's two dams, both deemed potentially dangerous by the state - choosing financial considerations over the fervor of some residents who wanted to preserve what they consider landmarks of their town.

The Pennsylvania Department of Environmental Protection said years ago that the recreational dams, which have been part of the town in various iterations for centuries, could fail during a major rainfall. Township supervisors had to decide how to meet new state standards.

Supervisors told the 80 or so people gathered at the Goshen Fire Company banquet hall that they had to make the best decision for all the township's 18,000 residents.

Supervisor E. Martin Shane acknowledged residents' strong feelings about the fate of Milltown Reservoir Dam and Hershey's Mill Dam.

"We find ourselves in a very untenable situation," Shane said.

A failure of the larger of the two, Milltown, on Reservoir Road just north of West Chester Pike, would threaten 39 homes and five businesses, according to engineering firm Gannett Fleming. The 20-foot-high, 350-foot-long earth-and-concrete dam has a drainage area in which sediment has accumulated.

Residents say the dam preserves open space and history, enhances their properties, and provides a place for people to fish, bird-watch, and ice skate. More than 1,000 people signed a petition to keep the dam.

"We have a force behind us to save this dam," said resident Paul Knox. "Not just a small number of us."

Among the alternatives, including one with a $10 million price tag, by a 4-1 vote the supervisors chose the least-expensive option for the Milltown dam, a partial breach that would cost about $1 million and do away with the reservoir, which some residents wanted to keep.

The partial breach would change the dam's status from "high hazard" to "low hazard" under state guidelines.

Township officials voted unanimously to get rid of Hershey's Mill Dam, at Greenhill and Hershey Mill Roads near Route 202, at an estimated cost of $270,000. The dam, which is 14 feet high and 450 feet wide, is bordered by only a few homes and has a drainage area that is less than a third of Milltown's.

The reservoir is dry now. A failure would have a small possibility of washing a car off Greenhill Road but would not damage any homes or businesses.

Saving Hershey's Mill Dam was a crusade for Neil DeRiemer, who lives next to it. He holds memories of looking out his bedroom window with his wife, who died last March, and watching a small waterfall cascading over the dam.

East Goshen officials gave him and other supporters one year to raise more than $400,000 to repair the dam. They raised $1,500.

Township officials faced two other options for the earth-and-stone dam: adding to the spillway and raising the top of the dam, which would cost more than $600,000, and partially breaching the dam, which would cost more than $270,000.

610-313-8207@MichaelleBond