Decision Document Signed for Upper McDonald Creek Bank Stabilization
Contact: Amy Vanderbilt, 406 888-5838
Contact: Mary Riddle, 406 888-7898
WEST GLACIER, MONT. – Glacier National Park officials announce that the environmental review process has been completed for proposed bank stabilization along Upper McDonald Creek after heavy rainfall damaged the road at milepost 19.25 in November 2006.
The Finding of No Significant Impact (FONSI) decision document was signed by National Park Service (NPS) Intermountain Regional Director, Mike Snyder on September 25, 2008. The decision was reached after review of environmental impacts and consideration of public comments on the environmental assessment that was released in August 2008.
The Going-to-the-Sun Road, a national historic landmark and civil engineering landmark, is the primary roadway that provides access to viewpoints, trailheads, picnic areas, campgrounds, and visitor centers in Glacier National Park.
In November 2006, Glacier National Park experienced a weather event that resulted in 9.1 inches (23.1 cm) of rain in a 36-hour time period and nearly 14 inches over a five-day period. This storm caused multiple creeks within the park to swell above their 100-year-flood stage causing notable damage throughout the park.
Emergency repair took place on several sections of the Going-to-the-Sun Road (Sun Road). At MP 19.25, located just west of the West Tunnel, soil nails were installed to stabilize unconsolidated soil along the bank of McDonald Creek. This was a temporary action to prevent further damage to the road and keep it open for visitor traffic the following year in 2007.
Permanent stabilization of the bank is necessary at this time to prevent further slumping (leading to loss of, or more damage to, the Sun Road at this location). In order to permanently stabilize the bank to protect the road, as well as reduce and prevent further impacts to park resources, the NPS will work with the Federal Highway Administration to have rock riprap applied to stabilize the bank. The large, angular riprap will extend approximately 300 feet along the bank and native species such as dogwood, cottonwood and willow seedlings will be incorporated into the riprap for screening.
To reduce potential impacts to spring nesting harlequin ducks and winter recreational use along the Sun Road corridor, work will be completed in late fall/early winter 2009-2010 when water levels are low.
Materials will be stored and staged at the project site, nearby pull outs, or at Logan Pit (which was already identified for staging and storing in previous planning documents).
The FONSI is available through the park’s planning Web site: http://parkplanning.nps.gov/parkHome.cfm?parkId=61
- NPS -
Did You Know?
Lake McDonald is the largest lake in the park with a length of 10 miles and a depth of 472 feet. The glacier that carved the Lake McDonald valley is estimated to have been around 2,200 feet thick.