Water Quality Protection During Elwha Dam Removal

glinesdamapril2013Officials from the City of Port Angeles and Olympic National Park reached agreement last week on a path forward for protecting the City’s water supply while continuing removal of the Glines Canyon Dam on the Elwha River.The National Park Service (NPS) plans to re-initiate removal of Glines Canyon Dam this fall. Removal of the 210-foot high Glines Canyon Dam began in September 2011 and is scheduled for completion in September 2014.

Approximately 50 feet of the dam remains in place. Notching a section of the dam this fall is expected to release less sediment overall than continuing to delay dam removal.

The NPS has completed a number of measures to improve protection of the City’s water supply, including the use of two powerful mining pumps and other operational improvements to the Elwha Water Facilities (EWF.) This fall, the NPS will remove a mound of sediment at the entrance of the side-channel that helps supply water to the City’s Ranney Collector, and complete construction of an alternate intake system at EWF through a $3.8 million contract awarded to Macnak Construction of Lakewood, Washington.

Issues surrounding water intake and treatment at the EWF began in the spring of 2012, with more severe problems occurring in the fall and winter of 2012, and led to a delay in continued removal of the Glines Canyon Dam. Problems at EWF began when sediment, gravel, and woody debris that were intended to be screened out by the water intake structure began moving further into the system, clogging pumps, filters and other equipment inside the treatment plant.

“Although the sediment has and is behaving as predicted, the water facilities have not,” noted Olympic National Park Superintendent Sarah Creachbaum. “The root of the issues is the surface water intake. We are very pleased to report that we have made a number of operational improvements at EWF. In addition, construction of an alternate intake will be completed by November.”

The City and National Park Service will continue to work together in good faith to discuss issues related to protecting the City’s water quality and quantity from the adverse impacts of dam removal.

“We are committed to continuing to work collaboratively with the City and look forward to successful completion of dam removal,” said Creachbaum.

“We are continuing to work with the National Park Service and are pleased with the positive cooperation between our two organizations to secure the City’s ability to provide water to the citizens of Port Angeles during the largest dam removal project in our Nation’s history,” said City Manager Dan McKeen.

The overall Elwha River Restoration project budget remains at $325 million.

September 12, 2013/Joint News Release - City of Port Angeles and Olympic National Park

IMAGE/Elwha River Restoration fb.com