Draft slump report cites surface water
A draft engineering report says the Haines Borough should address surface water flows on the Mount Ripinsky hillside in response to a ground slump that undermined a home, broke a sewer line and split Lutak Road in January.
“A comprehensive review of hillside surficial drainage and flow characteristics should be conducted to determine if any changes are warranted to flow patterns,” said the report by PND Engineers, Inc.
“It was made known to PND that many of the residents and local agencies have installed drainage systems to address on-site problems with no regulation of the overall drainage of the area. A good understanding of how the water is flowing is critical to developing a useful and effective drainage solution,” the report said.
“Homeowners have typically solved the problem themselves by redirection of surficial flows,” the report said.
The report said culverts, ditches or French drains can be used to handle surface water. It also recommends the borough consider drain blankets, cut-off drains, horizontal and relief drains to control subsurface water.
Borough facilities director Brian Lemcke this week was skeptical of the draft’s emphasis on surface water, and said the draft would be balanced with information from the state that hasn’t yet been compiled.
“I don’t buy the surface water (argument). Surface water may be a contributing factor, but nobody knows enough yet to start pointing fingers,” Lemcke said. “I’m not saying surface water is not a part of it.”
That the borough has not taken drainage into account on the hillside isn’t accurate, Lemcke said. There’s a series of ditches that collect water from as high as the Skyline subdivision and empty into a culvert at Oceanview Drive, he said.
Lemcke this week said that wells drilled in the area of the slump have found “soupy material” beneath layers of clay there that would make soil above them unstable.
The 30-page, geotechnical report released last month doesn’t name a specific cause for the ground shifting in the vicinity of Oceanview Drive and Lutak Road, but it does pinpoint a drainage ditch there as needing relocation.
“Part of this effort should be the immediate re-direction of water from recent ditches near the end of Oceanview Drive. It is our understanding that a recent ditch has re-directed water downhill toward the house below Lutak Road. Immediate consideration should be redirecting this surface flow to the east, away from developed areas,” the report said.
Lemcke said that information is inaccurate, and was based on verbal accounts that a new hillside subdivision by Juneau developer Jan Van Dort on the hillside drains into a spot near Oceanview and Lutak. The subdivision drains at a location lower on the hillside, Lemcke said.
The borough has spent about $70,000 on reports so far and has yet to identify a cause of the slump.
Resident Josh Moore, whose family has been renting since it was directed to move out of its home affected by the slump, said this week he’s still waiting for some assurances from borough or state officials that movement won’t recur. His home and three lots there are assessed at more than $300,000.
“This is the time of year to build or fix things. Nothing’s in place,” Moore said this week. “My insurance company is calling it an act of God and not covering it,” he said.
The ground movement lifted Moore’s house about three inches, leaving cracks in walls and also disturbing outbuildings. “Everything’s repairable but you don’t want to do anything until you know everything is fixed” and the cause has been addressed, Moore said.
Moore has been working with a contractor and looking at what he could do to stabilize his property, including possibly hiring his own engineering firm. “It’s kind of up in the air.”
Lemcke said: “My gut tells me it’s a combination of things and part of it is the natural condition of the ground here. Slides happen in this valley… I don’t know if we’ll ever be able to say what actually caused it, but we should have a pretty good, combined report by the middle of the summer” when the state’s information comes in, he said.
Lifetime resident and planning commission member Lee Heinmiller said borough code currently requires hillside developers to address drainage issues and to connect to a storm sewer system, when a connection is available, for subdivisions of more than four lots.
But drainage issues were “completely ignored” during much of the historic development of the hillside, Heinmiller said. “Back then there wasn’t any code addressing it, and even if there was, it wasn’t properly enforced.”