A major maintenance project at Boundary Dam on the Pend Oreille River in northeast Washington will require closing the Forebay Recreation Area and campground longer than expected.
Construction activities in the area, including truck traffic, for early work on the project have increased. To protect public safety, the recreation area and campground will be closed from Aug. 25 until Nov. 1.
“We hoped to limit the project’s impact on recreational activities, but safety must always come first,” Superintendent Jorge Carrasco said. “The amount of construction traffic and other work with large equipment have made it clear that allowing use of the Forebay Recreation Area during this time would not be wise.”
This yearlong project involves the removal and rehabilitation of a 312-ton gate used to maintain the seven sluice gates located at the base of the dam. The maintenance gate is located on the outside of the dam at its base. It is used to seal the dam in order to remove a sluice gate for maintenance or work inside one of the sluices. Sluice gates can be opened or closed to control the amount of water in the reservoir.
It has been 27 years since the maintenance gate was last removed for its own maintenance.
Throughout the project, periodic disruptions or access restrictions will occur in the Forebay Recreation Area, including closures for the campground, picnic area and boat launch.
“Boundary Dam provides about half the electricity Seattle City Light produces for its customers and is a significant contributor to the economy of Pend Oreille County,” Carrasco said. “This maintenance work is an important part of ensuring the operation of this vital resource for years to come.”
In preparation for removing the gate, a large concrete pad is being built at the Forebay Recreation Area. This work will continue through August.
Beginning Sept. 9, the reservoir will slowly be drawn down as much as 40 feet from its normal full level to an elevation of 1,950 feet. This drawdown and rapid, significant fluctuations in the water level may last through Sept. 19. At that point, regular operations would resume.
During the drawdown, the maintenance gate will be detached from the dam and floated to the nearby recreation area where it will be removed from the water. It will be placed on the concrete pad and housed for a year in the temporary building for the retrofit. Once the retrofit is completed in the fall of 2011, the reservoir will be drawn down again to return the gate to its permanent place on the dam.
With the reservoir drawdown, the namesake falls at Metaline Falls will reappear along with portions of the reservoir not seen since 1982.
While the reservoir will remain open for public use throughout the project, the low water condition during the drawdown will prevent access at all boat launch facilities on the Boundary reservoir, including Metaline Park, and Campbell Park immediately below Box Canyon Dam.
Seattle City Light is the 10th largest public electric utility in the United States. It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to nearly 1 million Seattle area residents. City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.