Assembly to hear report on hill slide
Property owners and Haines Borough officials are set to question experts on a mystery that’s lingered for eight months and cost upwards of $100,000 to investigate:
What caused a horseshoe-shaped parcel of prime land against Mount Ripinsky to slide toward Portage Cove last January? And what, if anything, can be done to keep it from happening again?
Representatives of PND Engineers, hired last spring by the borough to study the event, will address the assembly Tuesday.
“I want to know if it’s going to move again,” Victoria Moore said this week. Moore’s family vacated their picturesque, waterfront home last spring, as pressure on the house from ground movement separated the structure from its attached garage.
The so-called “slump” also split Lutak Road, broke a borough sewer line, and forced the relocation of electrical and cable TV utilities. It also influenced one landowner’s decision to stop plans for building a home nearby.
Moore said her family will move back in before winter and that they haven’t yet started in on repairs. They and borough officials hoped answers would come before they invested in fixes.
The borough recently buried a temporary sewer line that was installed to fix the broken one and the State of Alaska this week was scheduled to pave fractured sections of Lutak Road.
“I’m hoping people will ask the hard questions,” said borough facilities director Brian Lemcke, who expressed skepticism at results of a PND draft report in May that focused on surface water.
Test drills found slurpy soils as deep as 20 feet and beneath a layer of clay, Lemcke noted.
Longtime planning commission member Lee Heinmiller suspects that hillside subdivision roads, built parallel to the hillside during the past 30 years, acted as a series of dams, moving surface water horizontally instead of downward through historic creeks and drainages.
As a result, water from the mountain is absorbed into the ground, “supersaturating” it, he believes. He points to the disappearance of historic streams near Front Street as evidence of his theory.
“I’m not an engineer. But isn’t it logically a problem? It wasn’t as if they built a storm sewer system for all the (hillside) roading they did. If they did, you wouldn’t have that hillside supersaturated,” Heinmiller said.
Landowner Brian Elliott has a similar theory. Elliott was planning to build a home this year on a one-acre lot in a subdivision planned by Juneau developer Jan Van Dort. The slump is at the western edge of Elliott’s lot.
Elliott’s family has since moved into a house further up the hillside. “We’re definitely disappointed in the course of events. Who’s to say it won’t happen again?” Elliott said.
Homes and roads on the hillside have reduced places for runoff to go, he said. “Part of the problem is there used to be above-ground creeks. Now you don’t see anything. Now, the (water) is in the ground.”
“There’s a lot of anecdotal and preliminary thoughts that are out there but until they put together a report, it’s all interesting information without science,” said borough manager Mark Earnest.
Earnest and other borough officials tend to point to combinations of possible factors. Earnest cites high amounts of precipitation at the time of the slump, including a record November snowfall on unfrozen ground, followed by heavy December rains. Groundwater flows were also high this summer during road construction on Fourth Avenue, he said.
“I just think there’s a tremendous amount of water in that hillside. It rains here a lot and we don’t have a lot of creeks going down that hill. It’s all going into the ground,” he said.
The slump does raise questions about future hillside developments, including Van Dort’s, Earnest said. “We have a concern about the development of lots in that general area…I want to make sure that the borough, in approving any requests for any applications, that we’re not exposing the rest of the community to some situation down the road where there is a potential problem. We can’t put permanent utilities into any unstable areas. One of the most important factors in all of this is we don’t want to make the situation worse.”
Earnest said after the borough receives information from engineers, it can develop a plan to mitigate risk.
Facilities director Lemcke said he doesn’t have high hopes the slump ever will be fully explained. “I just hope it quits moving. If it keeps sliding down, it’s going to be a huge cost to everybody involved. Hopefully, it was just an adjustment.”