The Haines Borough Emergency Operations Center has identified seven areas where geologic instability is an ongoing concern. (Slide from Liz Cornejo’s presentation.)
Conditions in Haines are improving as the rain begins to subside. The National Weather Service’s flash flood warning for the community expired Tuesday afternoon, and the evacuation order for residents living on Cathedral View Drive and Piedad Road has been downgraded to a “be prepared” notice.
However, the Haines Emergency Operations Center warns that the ground is still unstable.
Local geologist Liz Cornejo is assisting the Haines Borough in its emergency response. At an assembly meeting on Tuesday she said there are concerns about the geological stability of seven areas in Haines.
“The instability in most areas is slowly decreasing as precipitation decreases. However, there is a lag,” Cornejo said. “The geotechnical instability is ongoing and has a slower decrease there.”
Areas of concern include Mosquito Lake Road, Lutak Road, Mt. Ripinsky, Picture Point, Beach Road and Mud Bay Road.
The emergency operations center has assigned a rating of “be prepared,” “elevated alert” and “evacuate” for each area of concern. Beach Road is the only area under a mandatory evacuation order.
“There are cracks above the south end of Beach Road, there’s unusual drainage flow, leaning trees and there’s also deeper soil, which means bigger movement or bigger consequence there.”
The Emergency Operations Center expanded the Beach Road evacuation area to include upper Mt. Riley Road. Residents are asked to stay away from the homes and popular sledding hill in that area.
In areas of town below Mt. Ripinsky the risk will decrease as precipitation decreases. Cornejo said geologists are keeping an eye on the water pressure, high water levels in creeks and sloughing.
The Picture Point and Highland Estates area is at an elevated alert level. Cornejo said it has experienced problems in the past, and small ground movements have been observed there recently.
“There has been current house movement at the bottom near the beach. It is an area known to have silt and clay deposits. It’s a pressure related event and we’re monitoring it with movement as well. Some residents have voluntarily left the area. That’s an area we are on high alert, but it is a slower type of event.”
Along Lutak Road there are debris flows, sloughing, clogged culverts, and flooding. So far mudslides in this area have been small, but numerous. She said that the risk in the Lutak area depends on the length of time spent there.
“A lot of the areas of Lutak Road are uninhabited, and you’re really just driving your vehicle through them. If you are moving, that is a lower risk versus if you are living or or working equipment there.”
Cornejo said there are moderate concerns about Mud Bay Road from the shooting range to Letnikoff Cove. There is steep terrain in the area, similar geology to Beach Road, and changes to surface water flow and sloughing have been observed.
There are also concerns about erosion on Mosquito Lake road and damage to the pavement that could be hazardous.
The borough has been collecting observations about changes to local terrain and groundwater flow using the Mountain Hub app. Observations can also be emailed to eoc@haines.ak.us
If any area needs to be evacuated, residents will receive a nixle alert on their phones and hear a repeated three-siren call. Evacuees will gather at the school for directions.
