The new and improved Bluefish hydro dam in the Northwest Territories is finished.

The Northwest Territories Power Corporation says the $37.4 million project was completed last week. It is the power corporation’s biggest construction project ever.

Bluefish is located about 50 kilometres northeast of Yellowknife. The corporation bought the Bluefish hydro site from Miramar Mining Corporation nine years ago for $12 million.

In 2009, the power corporation discovered that a hole had developed and there was a danger of the dam failing. The corporation came up with a rushed estimate of $18.9 million to build a new dam, underestimating both the scope and the cost of the job. But spokesperson Bob Kelly said that move saved the territory millions of dollars in the end.

"It's been a good bargain. It's paid for itself many times over, simply by the fact that we've been able to use low cost, green hydro power versus an estimated 11 million litres a year of diesel, which would be required if we didn't have that facility," said Kelly.

The Bluefish dam was originally built in the early 1940s to power the Con gold mine. Shortly after the Power Corporation bought it, the old rock and timber dam threatened to break, endangering cabins and homes downstream from Prosperous Lake.

The corporation says the new dam is expected to last for 100 years.