When Snohomish County Public Utilities set out to find new opportunities for renewable generation, they found it to the south in the Cascade mountain foothills of King County.
The utility, facing increasing electrical demand from a rapidly growing population, says it found two projects that Puget Sound Energy had explored, even federally licensed at one point a decade earlier, to build two small hydroelectric generating plants fed by two mountain lakes.
PSE opted to not go forward, but Snohomish County Public Utilities District picked up the property.
“We know there’s a lot more development coming to Snohomish County,” says Kathleen Vaughn, who leads the utility’s commission.
Snohomish County PUD says the two sites on Calligan and Hancock creeks, which feed out of the lakes, were considered as far back as the 1950s.
Now online, the two facilities can generate enough power to heat and light 10,000 homes, each plant capable of generating six megawatts each. Because the level of the lakes can drop during the summer, the plants may not run all year long, but since the rainy season is during the winter when power demand is at its highest, the utility says it’s more than happy to take that deal.
Snohomish County PUD says it saved money because the Calligan and Hancock powerhouses are virtually identical, and both were based on the same design as the Young’s Creek powerhouse constructed in Snohomish County in 2011. The utility claims the three hydro plants are the only ones built in the state in around 25 years.
The utility says it looked at 140 potential hydro sites in four counties but whittled the list down to 12 strong contenders. One of the requirements is that the hydro plants, which divert water from creeks and then return the water to those same creeks downstream, were not hosts to salmon runs.
Both Calligan and Hancock lakes are home to trout.
