Mill Pond dam removed as restoration project shutdown for winter
METALINE FALLS - The 134-foot-long, 55-foot-high concrete dam on Sullivan Creek is gone and the 64-acre Mill Pond it created is now a meandering creek again like it was 100 years ago.
Envirocon, the contractor, working for Seattle City Light shutdown for winter Nov. 17 and removed heavy equipment that has pounded the concrete and timber dams to pieces all summer. Mill Pond was slowly released down the creek to avoid downstream damage.
Mark Vanoss, a City Light spokesperson, said they removed the log crib dam and concrete dam to stream bed elevation during the summer. The summer fires in the area caused some early delays but by the end of the season they were on schedule.
They installed upstream bank protection structures; installed bank protection on Sullivan Lake Road approximately 2 miles east of Highway 31; installed bank protection at a sewer line crossing near Metaline Falls; and managed accumulated sediments to begin formation of the future floodplain and stream channels.
Vanoss said when the contractor begins work in the spring they will continue sediment management and site grading in the former Mill Pond.
Also scheduled is Sullivan Creek channel excavation and installation of more than 70 in-stream log structures.
An important part of the project is to replace and enhance recreation opportunities. They will build new hiking trails around the site; install new bridges at the former dam site and another at Mill Pond campground; construct new ADA accessible picnic pavilion with fireplace, improved parking and site re-grading at Historic Site/Elk Creek trailhead use area.
They will also install bear-proof food storage boxes and other campground improvements at Mill Pond Campground.
The final stage is implementing the planting plan across the entire project area as well as site cleanup and demobilization.
The $16 million Mill Pond Dam removal project is part of City Light’s Boundary Hydroelectric Project relicensing mitigation requirements. The total cost of all the restoration work planned by City Light in the watershed is estimated at $60 million and will take many years to complete.
Vanoss said the project is on budget and that there has been no change orders for the project based on unforeseen site conditions.
Most of the work, which is on the Colville National Forest, will be done by the fall of 2018 but monitoring after construction will continue until Dec. 2019.
Franklin Pemberton, Forest spokesperson, said the Mill Pond Campground, Mill Pond Historic Site, and Elk Creek trail head is closed to the public during construction through 2018.
This closure includes approximately 1.7 miles of hiking trails and approximately 1.2 miles of Sullivan Creek, above and below the dam to protect public safety.
In addition, a small clearing along the Highline Road is being used for staging and storing equipment during this project and is part of the public closure.
The Elk Creek Trailhead is temporarily relocated adjacent to Sullivan Lake Road near the entrance to the Mill Pond Historic Site. The upper loop of the Elk Creek trail, north of the Sullivan Lake Road, remains open with access to Elk Creek Falls.