The break left a 12-metre hole in the dam. ((CBC))

The dam at Scales Pond, just east of Summerside, P.E.I., burst in a spectacular crash of water and ice Saturday.

It was originally built to produce hydroelectricity, but hasn't been used for decades. Witnesses said the break left a gaping hole about 12 metres wide, and the force of the water took down nearby trees along the Dunk River.

"There was 30- or 40-foot [nine- to 12-metre] trees; they were just toppling them over just like matchsticks," Bill MacLean, who was on the scene shortly after the dam broke, told CBC News on Sunday.

"The force of the water pushing the ice, they were just hitting the trees and just shattering them."

Silt held up in the pond poured into the river below, and there are concerns about the effects on fish habitat.

"As that washed downstream, it can cover up these nests of salmon and trout that are below the site, so I suspect spawning success is going to be poor in that particular area," said Todd Dupuis of the Atlantic Salmon Federation.

Scales Pond had been a popular recreation spot for generations, particularly for fishermen, but the pond drained within hours.

Locals said they hope the province will rebuild the dam and restore the pond.