Under the 40-year operating license PSE received five years ago from FERC, and the license amendment issued last week, the utility will begin making substantial upgrades to the project's infrastructure and recreational facilities in September. Construction is anticipated to last, in stages, through 2014.
Key projects authorized by PSE's 2004 license and the license amendment include:
• Replacement of one generator in PSE's Plant 2 powerhouse, and replacement of one generator and retrofitting of four circa-1898 generators in the historic Plant 1 powerhouse. The improvements will add approximately 10MW of capacity (to 54MW total) without using additional water.
• Replacement of the water-intake structures and upgrade of the penstocks.
• Refurbishment of the existing concrete diversion dam that spans most of the Snoqualmie River just upstream from the crest of Snoqualmie Falls. The current dam, which varies between 5-18ft (1.5-5.5m) in height, will be lowered by 2ft (0.6m) and lengthened by 37ft (11.3m). The re-sized dam will reduce the crest of flood waters in the upstream city of Snoqualmie while providing better water conveyance to PSE's powerhouses.
• Installation of automatic shutoff gates in the gatehouse above Plant 2.
• Installation of turbine-bypass valves at Plant 2 to provide full water-flow continuation into the Snoqualmie River during abrupt generator shutdowns so that the river's flows for fish are unaffected.
Under the 2004 license, PSE will make significant improvements to its park and recreational facilities at Snoqualmie Falls. The enhancements include:
• Improved and reconfigured hiking trails and walkways in Snoqualmie Falls Park, including reconstruction of a boardwalk trail along the Snoqualmie River that leads to a stunning, river's-edge view of Snoqualmie Falls.
• Better riverfront access and parking for kayakers and boaters downstream from Plant 2.
• New recreation facilities and public restrooms in the lower-park Plant 2 area.
• New interpretive signage and displays.
• Extensive landscaping and habitat restoration.
• New fencing and lighting.
PSE's hydroelectric facility is part of the Snoqualmie Falls Historic District, listed in the National Register of Historic Places. To address the redevelopment project's effects on the district, PSE has developed a comprehensive agreement with the Washington Department of Archaeology and Historic Preservation and other interested parties.
The agreement's measures include PSE salvage and preservation of equipment, artifacts, photos, operational records, and other features from the Snoqualmie Falls operation - one of the Northwest's first hydro power facilities and the world's first completely underground powerhouse. PSE's plans also include rehabilitation of Plant 1's Carpenter Shop and Train Depot (both circa 1900), which together are expected to display historically significant features from the Historic District for interpretation and education purposes.
The 40-year operating license PSE received in 2004 for its Snoqualmie Falls hydro power operations contained a variety of FERC-approved plans for infrastructure upgrades. A year later, however, the US Army Corps of Engineers altered the Snoqualmie River's channel upstream from the falls for flood-reduction purposes. USACE's work changed the river's bathymetry and prompted PSE to seek corresponding revisions in its infrastructure plans. The revised plans were largely incorporated into the license amendment issued by FERC.
PSE estimates the total cost to redevelop its hydroelectric facility will be approximately $250M.
