SULTAN — For the next 45 years, Snohomish County’s largest dam is expected to be easier on the environment than it’s been for the past 45.
The Snohomish County Public Utility District’s power-generating system in the Sultan River basin was recently granted a new 45-year license, good until 2056, from the federal government.
The license renewal for Culmback Dam and the Henry M. Jackson Hydroelectric Project was based largely on a plan to make the Sultan River downstream from the dam more friendly for fish and recreation, PUD officials said.
The PUD worked on the plan for five years with government agencies, the Tulalip Tribes and environmental and recreation groups.
“It’s been pretty phenomenal, actually,” said Rich Bowers, Northwest coordinator for the Hydropower Reform Coalition, a national environmental group with an office in Bellingham.
“They completely opened that process up to public and agency participation,” Bowers said of the PUD.
The result is a plan to spend $21.4 million on projects to restore fish habitat and whitewater riding opportunities to the Sultan River, and more in upkeep over 45 years for a total of $69.5 million. The cost will be financed with bonds backed by power bills paid for by PUD customers.
Environmental groups, as well as the tribes, have signed off on the plan.
It’s an example of how hydropower can be environmentally friendly, said Bowers, who added that his group is not opposed to all hydropower projects.
Most larger dams were built between 30 and 100 years ago, with no environmental regulations or licensing requirements, Bower said. These include the Elwha dams on the Olympic Peninsula, finished in 1914 and currently being dismantled.
“We didn’t know what kind of impact dams would have on rivers back then,” Bowers said.
The new license for Culmback Dam and the Jackson hydro project became official at the end of September, PUD spokesman Neil Neroutsos said.
The previous license, issued in 1961, was for Culmback Dam at Spada Lake alone. The Henry M. Jackson Hydroelectric Project, added in 1984, is made up of several parts.
The dam was built in 1965 to expand Spada Lake and increase the county drinking water supply. About 80 percent of the drinking water for Snohomish County comes from Spada Lake, via Lake Chaplain, to the city of Everett.
In 1984, the dam was raised, quadrupling the size of the lake, according to the PUD. That same year, a 4-mile tunnel, 10 to 14 feet in diameter, was bored through Blue Mountain and a smaller, 4-mile pipeline was added to divert water from the lake to a new pumphouse downstream on the Sultan River.
There, four turbines generate about 5 percent of the PUD’s power, enough for about 35,800 homes.
The low water flow caused by the dam and the pipeline made life tough for fish and took away what once was a prime whitewater rafting spot.
Side channels to the river, where fingerling salmon often stopped to eat, dried up. Debris that formerly was washed out has accumulated instead. When a big flow comes, it’s often a torrent.
One project involves adding more dead trees and wood to the river to add more variety to flow conditions, creating pools where fish can rest.
Another involves reopening many of the former side channels, either by digging or by placing deadwood where the water will naturally divert into the former streambeds.
Work on both of these projects probably will be done in the fall of 2012 or the spring of 2013, Neroutsos said.
The water temperature in the river will be raised slightly by releasing water from closer to the surface of Spada Lake through the dam, likely in 2012, he said.
For whitewater rafters, an access trail will be built and, starting in about 2013, more water will be released from the dam on several occasions per year to mimic natural high flows, Neroutsos said.
The top of Culmback Dam will be opened to hikers, possibly by next spring. Improvements to boat launches in Spada Lake also are planned.
Next week, the PUD is planning opening ceremonies for its Youngs Creek Dam, a “microhydro” project on a creek south of Sultan. The $29 million dam, 12 feet tall and 65 feet across, is the first new dam built in the state in more than 25 years, PUD officials say. It’s expected to generate enough power, on average, for 2,000 homes.
The PUD also operates an even smaller dam at Woods Hole near Monroe.
Bill Sheets: 425-339-3439; firstname.lastname@example.org.