A broken city sewer line and a 2016 landslide have brought a maelstrom of litigation down on a Nuuanu Valley neighborhood, driving one resident away after a chunk of hillside crashed through a wall of his home between Puiwa Road and Polohiwa Place.

It’s a recent example of an age-old problem in the valleys of Oahu, where experts estimate that more than 70,000 residents live in areas that have been geologically unstable since Hawaii’s peaks first burst through the Pacific Ocean.

“People like to live on hillsides and to have a view because it’s quiet and beautiful, but there are problems that can occur,” said Honolulu City Councilwoman Ann Kobayashi.

Eugene Garrett, owner of the damaged home, is suing the city and several of his former neighbors. Garrett wouldn’t speak to Civil Beat because “he gets worked up when discussing his situation,” his attorney, Jeffrey Miller, wrote in an email.

Garrett claims in the suit that he reached out to city and state officials after the landslide, but got no help.

He filed a lawsuit against the City and County of Honolulu last November, alleging the busted sewer line caused the landslide that forced him from his home. He also sued residents around him for failing to maintain their portions of the area’s hilly terrain.

“The city is claiming it’s not their responsibility,” Miller told Civil Beat. “The only alternative is to file the lawsuit.”

The city contends its sewer line didn’t cause the landslide. It states in a countersuit the sewer line problem resulted from residents not taking care of their property.

As for the residents dragged into the civil case brought by Garrett, they deny in court documents that their actions (or inactions) had anything to do with the landslide. Their claims mostly boil down to placing blame on neighbors above, beside or below them.

Because of the number of parties involved in the suit, complaints are still being served and depositions answered. Miller doesn’t expect to get a trial date until at least next summer, and he said appeals could drag the case on for years longer.

The city is the target of six of the eight counts listed in Garret’s lawsuit, which alleges negligence and seeks payouts for damages.

Homeowners who are defendants in the lawsuit could not be reached for comment, except for one family that said they would not comment on the advice of their lawyer.

‘The Old March Of Time’

The volcanoes that created these islands also created problems for future residents on their slopes.

When valleys formed, lava flows and erosion left a step-like pattern on the slopes, said Steve Martel, a University of Hawaii geophysics professor.

The issue lies in “troublesome soils,” said Horst Brandes, a civil engineering professor at UH. These soils made of smectite clay are grainy, very fine and prone to collapsing when exposed to enough water.

“What looks like very impermeable material is in fact pretty permeable, more than people realize,” Brandes said.

Over time, rocks would weather, fall off these “steps” and create slopes of weak soil below cliff faces. It’s on these slopes that developers built many valley neighborhoods in the 1940s and 1950s, before much was known about land stability.

“If you can use the past as a guide to the future, then working out the geologic history can help in evaluating the susceptibility to landslides in certain areas,” Martel said.

Not all hillside residents need to worry, Brandes said, adding landslides usually occur in an area after enough underground water builds up.

That’s what happened in Manoa in 1988. A deluge on New Year’s Eve caused a landslide in the Woodlawn area affecting 35 acres and 429 residents, costing the city $25 million to mitigate and prompting the City Council in 1989 to restrict building permits in valley areas adjacent to past landslides.

Mayor Kirk Caldwell’s current residence in Manoa valley sits in one of those areas.

The risk of landslides isn’t news to Manoa residents, some of whom say it affects their property values.

“The old march of time is going to cause problems,” Manoa Neighborhood Board Chairman Dale Kobayashi said. “But there’s nothing they can do about this.”

A Shifting Slope

In the Nuuanu Valley, attorney Miller said that the city’s sewer line could have been leaking, and therefore saturating the hillside, since 2009.

Garrett moved into his home in 2010, and a retaining wall behind his house became the responsibility of the rear property owner when the two entered into an agreement in 2013, according to his lawsuit.

That same year, the city lined the inside of its aging sewer line that stretched across several properties above Garrett’s, the suit says.

“(Garrett’s) residence has suffered significant damage, been rendered uninhabitable, and will eminently result in total destruction of the residence,” the suit says.

After the landslide, Garrett contacted state and city officials. The city departments of Planning and Permitting and Environmental Services would not send an engineer to his property, according to the lawsuit. The Board of Water Supply conducted a test and found that water on the hillside may have come from a sewer line, the suit says.

The city eventually installed a temporary sewer pipe, which also broke because the land kept sliding, eventually leaving a 20-foot drop behind one house where the hillside once was, the suit says.

Cliff Tillotson of Prometheus Construction, has been working on mitigating landslides and rockfalls in Hawaii since 2002. He said the Puiwa hillside in Nuuanu is the worst case he’s dealt with.

Tillotson said he literally battled the hillside to save a home next to Garrett’s. Prometheus installed shotcrete, which looks like a rock wall, along with drainage at the back of the property. The constantly shifting land drove up costs, but Tillotson said he kept his quoted price of $70,000 to the elderly homeowners, who are now among those who have been dragged into the lawsuit.

Costs to protect hillside properties can climb quickly for homeowners. Tillotson estimates that a full system of anchors and tiebacks could cost around $30 to $40 a square foot.

Still, “It’s a lot cheaper than losing the house,” he said.

Mitigation measures do have their limitations, however. The hill behind Garrett’s residence pushed past anchors, netting and several wooden beams before smashing into the home.

Inconsistent Governmental Response

The city’s countersuit tells a different story than Garret’s.

“Plaintiff and others have conducted grading, excavation and other activities which have caused the land to slide, move and collapse, destroying the City’s sewer line and manhole structures,” according to the countersuit.

The city alleges that because residents didn’t take care of the hill, the landslide broke the sewer line, not the other way around.

City lawyers wouldn’t comment on the ongoing case.

The city and state’s record in dealing with landslides or rockfalls is far from consistent.

In 2012, the state Department of Land and Natural Resources removed boulders that hung from private land above Kula Kulea Place in the Kalihi Valley after state Rep. John Mizuno wrote a letter to then-Gov. Neil Abercrombie urging him to rid the hillside of the large rocks.

But last year, when Mizuno wrote letters to both the city and DLNR after a sinkhole formed in a Kalihi resident’s yard, they both replied that nothing could be done because the problem was on private property.

“The issues outlined by the residents are a private matter and should be investigated individually or collectively by them,” DLNR Director Suzanne Case wrote in a letter to Mizuno. “We are sympathetic, but the State is not responsible to either investigate or mitigate those problems.”

Mizuno said water beneath the surface continues to flood one homeowner’s yard even today, but the city’s Department of Facilities Maintenance told Mizuno in 2015 that none of its pipes is leaking.

The landslide in the Kalihi Valley has already damaged property, and Mizuno said residents predicted it would happen. They have resorted to taking up a petition and writing letters to the state and city themselves, but nothing has been done, he said.

“I’ve seen this movie before, and I don’t like how it ends,” Mizuno said.

In the late 1950s, when runoff from cliffs above Waiomao Street in the Palolo Valley threatened homes, then-city engineer Yoshio Kunimoto infamously told residents to just sell their properties. One owner heeded his advice and lost his life savings, the Honolulu Advertiser reported in 1956.

This area in Palolo still gives homeowners headaches. Water underneath Kuahea Street caused a sinkhole to form in the road, and Councilwoman Kobayashi said that there may be a leak somewhere causing the land to slide. The water drove several residents from their homes.

Some work has been done, but the contractor tasked with carrying out the city’s improvement on Kuahea Street filed for bankruptcy in April and progress has halted.

“I think the city’s responsible if the city’s pipe breaks,” Kobayashi said.

There are no state laws or city ordinances that specifically address building in landslide-prone areas. But the city Department of Planning and Permitting has an extensive permit review process for both public infrastructure and building permits for all areas.

The DPP rejected an Aina Haina development in 2006 in part due to the potential for landslides in the area.

DPP has no maps or records on landslide-prone areas. But the city ordinance from 1989 that temporarily banned building permits in certain areas mapped slopes in Moanalua, Manoa, Palolo, Aina Haina and Kuliouou as troublesome areas.

A U.S. Geological Survey from 1995 expanded that to include all valleys between Moanalua to Hahaione.

As of 2015, around 78,000 residents lived in or near these valleys, according to U.S. Census tract data.

Read Garrett’s complaint and the city’s countersuit below.