No easy answers as to future of area shifting and sliding
Ground shifting on the Oceanview hillside was first reported Jan. 16 and continues. A main sewer line that runs through the approximately five-acre area was breached last week but was diverted within 24 hours to maintain service to about 120 homes.
The assembly passed the disaster resolution unanimously Friday in order to begin the process of requesting state funds to help with the response. The assembly at its Jan. 24 meeting allocated $75,000 to establish and staff an emergency command center, hire a drill rig to conduct geotechnical investigations, establish monitoring equipment and perform emergency temporary repairs to the sewer main.
The disaster resolution states “disaster emergency is now exceeding the ability of the borough to adequately safeguard life and property and minimize the effect of environmental and structural damage.”
The resolution specifically asks for state assistance with “temporary housing for impacted residents, public disaster assistance for emergency protective measures, temporary and permanent repairs to borough sewer, water and transportation infrastructure” and with technical assistance to continue evaluating and responding to the issue.
Mayor Stephanie Scott said the disaster declaration is a tool to get funding from the state, if approved by Gov. Sean Parnell. The bulk of the responsibility regarding response to the situation would remain with the borough.
According to Jeremy Zidek with the Department of Military and Veterans Affairs, Division of Homeland Security and Emergency Management – the state agency responsible for emergency management - response staff at the department received the disaster declaration from the borough and is gathering more information to pass along to the governor and his cabinet. They make the final decision on whether the borough will qualify for state disaster funds. But Zidek said the state would likely let the borough keep maintaining its active response and wait until the event “stabilized” to come to Haines and gather more information.
“The borough has been doing a great job working through the event,” he said. “This is really what we like to see at the state level; they deal with the incident themselves, keep us in the loop and let us know when they need help. We are working very closely with them and explaining options and if things get out of hand, how they can call upon state assets.”
That’s not to say the state isn’t already involved on many levels. While Oceanview Drive and the utilities in the area fall under the responsibility of the borough, Lutak Road is a state road. Alaska Department of Transportation crews have been working with the borough to monitor movement and keep Lutak Road passable.
“Short term, it’s a maintenance issue for us,” said Al Clough, Southeast Regional Director with DOT. “We are doing quite a bit to investigate the issue, working with the city and on our own, so we can build a solution.”
Chuck Correa, regional pre-construction engineer with DOT, said there have been several similar slide and slope incidents in Juneau, Sitka and around Southeast he can remember in the last 15 years. But each one has its own characteristics.
“This one in Haines, it’s unique in that it is very slow moving so far,” he said.
Usually, slide events happened very quickly or overnight, damaging roads, houses and properties all at once.
“The more common event is a sudden failure and then we go out and it’s a cleanup operation,” Correa said.
A slow moving event requires more patience, Correa said, and examination of data to try to determine a “causative effect” and develop a long range response. But heavy snowfall this winter is also hindering data collection and slowing down the process even more.
“There’s a lot of questions we’d like to look at, but can’t until spring,” Correa said.
And even then, there is always one, very temperamental factor that plays a large part in keeping geological events largely unpredictable.
“It’s Mother Nature,” Clough said. “You can have the best data available and Mother Nature will turn around and smite you.”
Cindy Buxton is a local geologist familiar with the bedrock geology of the Haines area. She emphasizes she has little experience in geological engineering.
Buxton observed some of the drilling as it took place on Oceanview Drive as engineers gathered samples to better understand what was happening under the surface. She said in drill holes on Oceanview Drive, a clay-rich silt layer was hit about 20-feet down that was very saturated in water. A hole in Lutak Road revealed a wet layer of sand at about the same depth.
“When these materials get very wet they can lose their cohesiveness and strength and the materials above them can start sliding on these layers if there is a steep enough slope,” Buxton said.
She said the area has a “dynamic glacial history,” and that could be causing lateral changes in the distribution of clay and sand layers.
“The sand, silt, and clay were deposited in a body of water, such as a lake, that likely formed as the glaciers were retreating, or may have been deposited in saltwater out in front of a glacier.”
She emphasizes that the testing done by the engineers collecting the samples will be able to reveal many more details about the sub-surface materials.
Technically, she said, the mass-wasting event is called a slump, although it’s not acting as a strict textbook case. Here is how Buxton illustrates the movement:
“It is a bit like a flattened bowl sitting on a slippery slope. Imagine the bowl sliding slowly down the slope and at the same time you put a little weight on the top edge of the bowl. As the bowl is sliding down slope, the bottom edge tilts up slightly (i.e., the bump on Lutak Road near Front Street), resulting in rotational and translational movement. The bowl is for the most part sliding as a unit. However the earth is not that rigid, so small cracks are opening up in the middle of the horseshoe-shaped area as well as large cracks on its edges.”
Besides the sewer main break, the rough road, the contingency plans in place should Lutak Road be closed and the displacement of one family thus far, the slump could have even more long-term effects.
Brian and Sarah Elliott bought just over an acre of property on the hillside in the summer of 2010. They liked the neighborhood, the proximity to town and most of all, the view over the water. But now, Sarah Elliott said she is glad the couple didn’t begin construction on their home last summer as they originally planned.
“We’re actually feeling very fortunate that we don’t have a big, brand new home there right now,” she said.
Plans were in motion to build this summer. A pad and driveway were laid and the couple had a houseplan and a builder lined up, ready to begin construction as soon as the ground thawed.
While the sewer line that was compromised last week runs through the property, Elliott said their property doesn’t appear to be on the slab of earth actually moving.
Still, before moving on with construction, Elliott said she wants a thorough explanation from engineers and contractors about what is happening and what the outlook is for the area.
“Now that this has happened, I am personally extremely hesitant to move any further in any direction with development on the property,” she said.
The Elliotts bought one of three lots for sale by developer Jan Van Dort. Real estate agent Jim Studley said Van Dort ceased development on the property over the last couple years.
“They were not stopped being developed because of the slump affecting the road, but because of the slump in the market,” Studley said.
But obviously, he said, the present situation adds concern to if and how to move forward with development in the future. Studley said decisions about the property depend on information engineers compile and what the borough decides is necessary to stabilize or repair the area.
“(Van Dort) is not going to develop them until the market improves and this is definitely going to have an effect on his decision making,” Studley said.
The borough continues to release daily updates of the situation. In the last week highlights and developments include:
• A sudden increase of movement on the evening of Feb. 1 caused concern and revealed cracks had opened wider and deeper on Lutak Road. One family on the Oceanview Drive side of the slump decided to stay elsewhere for one evening because of the movement, but returned to their home the next day.
• State crews filled in cracks and smoothed out a large heave in Lutak Road.
• Warmer temperatures caused some snow melting and revealed an old manhole that borough officials did not have on record. The manhole was compromised by the ground shifting and broke the sewer line. Residents in the area were asked to reduce their water and sewer usage while crews made repairs and re-routed the sewer line.
• The damage to the sewer line allowed mud, sand and gravel to enter the line. The borough consulted with Juneau city officials about equipment in Juneau that could help remove debris from the sewer.
• The borough awaits detailed data from engineers monitoring the movement with specialized sensors. Manual measurements by the borough along the top of the slide show a movement of eight to nine inches in the last week and a half.