State geologists say an evacuation alert for the area around a Dec. 2 landslide that damaged or destroyed dozens of homes in Haines could remain in place for months.
A Dec. 18 update on the status of the 600-foot slide that collapsed a hillside overlooking Beach Road, southeast of downtown Haines, explained that the Alaska Division of Geological and Geophysical Survey (DGGS) has no way of knowing the stability of the slide area.
“Because DGGS does not have the data or expertise to evaluate the stability of the fractured rock mass, one must consider freeze/thaw activity, heavy rain, snow load, seismicity, high winds shaking trees, and other factors as potentially capable of triggering a new slide with no advance warning,” the statement read. De Anne Stevens, chief of the DGGS Engineering Geology Section, said Monday that the situation for the area of concern around the slide was unchanged.
“That central area adjacent to the beach road slide remains off limits due to the uncertainty of the stability of the slide area,” Stevens said.
An assessment by geotechnical experts will need to be completed in order to know the stability of the slide and understand continuing risk.
A statement posted to the Haines Borough website last Tuesday said that the Borough wanted to reassure the community that the rain and flooding event that triggered the slide was highly unusual.
“The event is considered a 200-500 year storm event where we received 10.26 inches of rain in a short period of time (48 hours). There was a 0.2% - 0.5% chance of this happening in any given two day period. Our storm started with 5.49 inches of rain in 24 hours — an all time daily precipitation record going back to around 1926 and considered a 25 to 50 year amount. The next day we received more rain, then more. The cumulative effect of all of this rain created an extraordinary (anomalous) event,” the statement reads.
Haines Borough Mayor Douglas Olerud said Sunday that 20 homes in the Beach Road slide area remain under the evacuation alert.
A Dec. 21 situation report from the Alaska Division of Homeland Security and Emergency Management reported that the Red Cross was still sheltering 11 survivors.
The Alaska State Troopers suspended the search for two missing Haines residents whose homes were in the path of the landslide on Dec. 7.
Contact staff writer Sam Ferrara at 459-7575.