| Seattle City Light
Skagit Rock Slide Update
|For Immediate Release:
11/18/2003 11:07:00 AM
|For More Information Contact:
Scott Thomsen (206) 386-4233
Skagit Rock Slide Update
NEWHALEM, WA — Seattle City Light
is working with the Washington State Department of Transportation (WSDOT), the
National Park Service and other agencies at the scene of a rock slide below
three City Light dams on the upper Skagit River. Last night an additional
rockslide occurred, measuring 15 to 20 feet high and 40 feet wide. This now
blocks the previously cleared emergency access lane on Highway 20. The original
slide, consisting of two to three million cubic yards of debris fell and blocked
State Route 20 on Sunday morning, November 9. Several million more cubic yards
of debris could come down the mountain at any time.
The Nov. 9 rockslide did not damage any City Light facilities.
Highway 20 is closed indefinitely at Milepost 120 with closure signs posted
along the Highway at I-5 and Highway 530.
- The slide area is one mile east of the town of Newhalem and
one mile west of Gorge Dam at Milepost 121.5 on Highway 20. The town of
Diablo, located four miles further east of the slide, is isolated but not
threatened by the slide. It is home to about 37 people who are City Light
employees and their families. Road access is also cut to Diablo Dam and Ross
Dam. A helicopter is ferrying workers to these dams and is also bringing in
supplies, food and mail to Diablo residents.
- Geologists cannot predict when new rock may fall. In a
"worst case scenario," a slide into the riverbed could create a
rock debris pile as high as 200’. As water rises behind this debris pile,
the pile could collapse, causing a sudden release of water. That situation
could cause damage and flooding in Newhalem, but is not expected to cause
flooding in any communities below Newhalem. There are 31 people currently
living in Newhalem. While some debris is currently in the river, water flow
is not obstructed at this time WSDOT consultants are standing by to get
visual inspection by helicopter as soon as possible.
- City Light and WSDOT have conducted community meetings with
Newhalem and Diablo residents and informed them of the situation. A
contingency evacuation plan is in place for Newhalem residents.
- Over the past 24 hours Diablo has received 3.5 inches of
rain. City Light expects a total of about nine inches of rain through
Wednesday. The utility will maintain the level of Gorge Lake about 18 feet
below full pool to leave considerable space in the likely event a new slide
occurs. The snow level will be about 5,000 feet through Thursday, then drop
to 1,000 feet by Friday.
City Light will provide more updates as necessary.