Snohomish County Public Utility District No. 1

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Customer Service (M-F 8a-5:30p): 425-783-1000

Jackson Hydro Project

Celebrating 10 Years for Jackson Project Relicensing

Jackson powerhouse

The Henry M. Jackson Hydroelectric Project, which began operating in 1984, is located in the Sultan River Basin. The 112-megawatt hydroelectric generating facility produces about 7 percent of the PUD’s power needs. In addition to generating enough power for 53,200 homes using a clean renewable resource, the project also provides recreation, enhances fish and wildlife habitats, provides an element of flood control and assures an abundance of clean drinking water. A new 45-year license was issued by the Federal Energy Regulatory Commission (FERC) in 2011 (click for details).

How does water get from Spada Lake reservoir to our water supply?

Water from the lake flows through a tunnel/ pipeline before reaching the powerhouse on the Sultan River, downstream from the dam.

After traveling through the turbine-generators at the powerhouse, most of the water goes back into the river. Some of it flows to Lake Chaplain where it becomes part of the water supply. Water from Lake Chaplain is distributed to 75 percent of Snohomish County’s population or is used to maintain proper water flows for fish populations in the Sultan River.

The Henry M Jackson Hydroelectric Project was built in two phases. Phase I, which was completed in 1965, involved the building of Culmback Dam and the creation of the Spada Lake reservoir to increase the water supply. Phase II, completed in 1984, involved raising Culmback Dam 62 feet, which quadrupled water storage capacity of Spada Lake. The Spada Lake reservoir covers 1,870 acres (1,970 acres at maximum flood) with 17.3 miles of shoreline. Its maximum normal elevation is 1,450 feet.

We go to great lengths to ensure that the wildlife and aquatic resources affected by the Jackson Project survive and thrive. This effort is part of our agreement with the Federal Energy Regulatory Commission (FERC) and is also part of our own commitment to improve the community in which we live, work and play. Our biologists endeavor to maintain and improve the wildlife and fish habitats in the Sultan Basin area.

In addition, day-use recreation sites around the perimeter of Spada Lake reservoir are available for public use. The facilities provide access for fishing and boat launching at two locations, picnic areas, trails, viewpoints, interpretive signs, and public restrooms. Because Spada Lake reservoir provides drinking water, swimming, board sports and overnight camping are not allowed in the area. Only row boats and electric-powered boats are permitted on the lake.

The Jackson Project was dedicated in 1984 to the memory of Senator Henry M. Jackson, Snohomish County native who became one of the most influential senators in U.S. history.

Spada Lake Reservoir & Sultan River Access

Updated 08/29/2021

Check out the weather conditions before heading up to the Basin, see the "Rain, Wind, Reservoir & River Conditions" page.

Due to high fire danger NO FIRES ARE ALLOWED.

REGISTRATION is free and is REQUIRED to use any of the roads and recreation sites. Sites are open daily from dawn until dusk, unless indicated otherwise here. At all recreation areas on PUD property, please practice social distancing and follow state mask requirements. 

The Sultan Basin Road is a County maintained road and is paved for the first 10.5 miles.  The final 3 miles to Olney Pass (end of County road) are gravel, as are all roads on PUD property within the Sultan Basin. 

OPEN: The South Shore Road and associated recreation sites, including access to the DNR Greider Lakes Trail are OPEN to vehicular traffic.  The South Fork and South Shore recreation sites offer the only boat/kayak launches on the reservoir.

PARTIALLY OPEN:  The South Shore boat launch is closed to trailered boats due to recent vandalism.  However, kayaks and other watercraft may be carried to the lake and launched here.  Trailered boats can still use the South Fork launch.

OPEN: Culmback Dam Road is OPEN to the Gateway Site. Pedestrian and bicycle access are OPEN across Culmback Dam. To protect the public and our essential workers, please practice social distancing with employees on site.

OPEN: Sultan River Canyon Trail is OPEN.

PARTIAL: The outer gate at 116th Street is open; however, the inner gate is closed to maintain social distancing for essential workers. Pedestrians may access the area inside of the outer gate, however, no access past the inner gate is allowed at this time.

PARTIAL: The Lake Chaplain Road and Diversion Dam Road areas are open daily, from 6am- 6pm, with the exception of Friday/Saturday/Sunday when the outer gate on the Lake Chaplain Road will close at 3:00.  There is no public vehicular access across the Sultan River in this area, thus it IS NOT an option to bypass traffic on highway 2.

We will reassess the situation and update this website as applicable.



From Everett/Monroe: Take US Route 2 east through the town of

Sultan. A quarter-mile past town, turn left (north) onto Sultan Basin

Road. Follow the Basin Road 13.5 miles to Olney Pass.

From Seattle: Take State Route 522 east to Monroe. Take US Route

2 east and follow above directions.


From Olney Pass, follow the road left/west 1.4 miles to Culmback Dam and the Gateway Trailhead, or

Follow the road right/east 3.2 miles to the South Fork recreation site and boat launch, then continue an additional 2 miles to the South Shore recreation site and boat launch.

For more details:

Spada Map (click to view)
(click to view map)


Keith Binkley

Dawn Presler