Friday, June 5, 2009

Western North Carolina Landslides: An Urgent Concern

Photographs of the Donin home on 93 Wildcat Run Road before and after the January 7, 2009 landslide.

January 2009: A Month of Landslide Disasters

Rain is the usual catalyst for landslides and it rained a lot in western Washington, the city of Portland and Western North Carolina at the start of the new year. Landslides claimed 200 homes in Washington, dozens in Oregon and one in North Carolina.

It isn’t often that the press provides an in-depth look at the deliberately hidden costs of building homes on hazardous ground but in March 2009 two newspapers took on the issue.

The New York Times: Landslide Real Estate is a National Concern

In his extensive multi-state hazard report, "Increased frequency of landslides remains largely ignored despite risks," Scott Streater noted that these often dangerous and always financially ruinous events are not confined to the west coast. Over a 10 month period, December 2003-September 2004, landslides killed six Western North Carolina homeowners.

During the course of his research, Mr. Streater found that most state and county governments do not regulate or disclose hazardous-land conditions. The landslide-active city of Seattle is a rare exception. The city has been hazard-mapped and landslide real estate risks are minimized. Mr. Streater warns that, unlike Seattle, ... "most of the rest of the country lives with the incalculable risk of a catastrophe."

Bill Burns, an engineering geologist with the Oregon Department of Geology and Mineral Industries, told Mr. Streater that he is concerned for homeowners because on-going studies indicate that “there’s literally thousands and thousands more landslides than we originally thought." Mr. Burns added

When someone applies for a building permit, they assume that if they get it, the house is safe. But there’s no information on landslides. There’s no way to know whether there’s a chance the house you’re building is going to slide down a hill, or that something one day is going to slide into it.
The Asheville Citizen-Times: Western North Carolina Landslide Real Estate is a State Concern

Sometimes it takes just one more tragedy to provoke a reaction. The Donin landslide, January 7, 2009, prompted the Asheville Citizen-Times to publicize the fact that much of Western North Carolina real estate is landslide-hazardous. The following is a reprint of the paper's now-archived landslide report.

"Homes in harm’s way on many WNC slopes"

Little regulation on development puts lives at risk

By Jon Ostendorff-March 1, 2009

Maggie Valley — Bruce Donin carefully stepped through a frozen pile of rubble last week in the spot where his retirement home once stood.

If the basement had withstood the landslide that crushed his house, Donin said, he might have found a few remaining possessions that came with the couple’s move from Florida.

“We brought up 30 years of not only valuable possessions but collections and family photographs,” he said. “Every possession we had.”

A January downpour turned the hill above the Donins into a morass of mud that shoved their house 300 feet as it broke apart, bending half-inch steel bolts as if they were sewing pins.

The Donins say they were not told the slope above their home had been found unsafe in a government inspection, and they think what happened to them should serve as a warning as North Carolina considers regulating steep-slope development.

Lawmakers will take up the issue in coming weeks but will do so with limited information regarding the extent that growth is putting people in danger.

The Asheville Citizen-Times, in an investigation into mountainside building, examined hundreds of erosion inspection reports, reviewed a state database of known landslides, examined maps of landslide hazard areas and interviewed environmentalists, builders, real estate brokers, state
legislators and government scientists.

The newspaper found:

Almost 1,000 homes and 300 undeveloped lots are in the path of potential landslides in Watauga County, where state landslide hazard mapping is complete, according to an environmental group’s estimation.

In Buncombe County, where maps are scheduled to be completed this month, geologists found evidence of 861 landslides, with more than half on manmade slopes.

Six people have died, five have been injured, and 40 homes and buildings have been destroyed in 534 landslides and debris flows since 1990.

The costs of landslides in the last 20 years hasn’t been officially tallied. But major road and structure damage listed in state records combined with the newspaper’s estimate of the housing loss puts it at nearly $13.4 million.

Inspectors in Haywood County, where two homes have collapsed since 2003, noted seven instances last year in which lives or property were at imminent risk from slope failures.

Hidden problem

Landslides, unlike hurricanes, tornadoes, and flooding, are almost impossible to predict.

What scientists do know is that they have happened here for hundreds of thousands of years and are happening today, more than most people realize and at a time when more people are building on mountain slopes.

A landslide damages property almost every year in Western North Carolina. Big slides happen about once every nine years in the region, the N. C. Geological Survey estimates.

Most don’t grab the headlines.

A landslide in Jackson County on a private road off N.C. 281 destroyed a cabin during the hurricane season of 2004. No one was injured. A slide that same season not too far away on N. C. 107 destroyed a few storage units.

But others are far more devastating.

The 2004 hurricane season was the worst in recent memory. Back to back storms Frances and Ivan saturated the mountains and caused widespread flooding.

On Fishhawk Mountain, above the tiny Peeks Creek community, a two-mile-long debris flow wiped out 15 homes and killed five people.

An even more devastating disaster played out in Watauga County in 1940.

Back-to-back tropical storms triggered landslides and left 14 dead— more than half of them children. One slide rolled over U. S. 441 closing the road and making travel in the region tough.

Even earlier in 1916, two storms drenched the region, flooding the French Broad River watershed with 22 inches in 24 hours and setting a state record that stands today.

A community called Basin Creek in the northern mountains was wiped out by a landslide. The flood shut down railroad service to Asheville, almost bringing the economy to a halt.

At least two people died in Transylvania County.

“The reports were that you could stand in Brevard and see landslides on the hillsides all around,” said Rick Wooten, who leads the landslide hazard mapping effort for the N. C. Geological Survey.

Hard facts

At its most basic level, the geology isn’t hard to understand.

The WNC region has steep mountains. When heavy rain falls on those slopes for an extended period, the water saturates the soil, and it slides off the bedrock. Gravity sends the mud downhill, sometimes for miles, but often for just a few hundred feet.

Scientists have a pretty good handle on how much water it takes to produce landslides in WNC: The threshold commonly accepted among experts is 5 inches in 24 hours. Most of the disastrous slides in recent history have followed rains of that magnitude.

While scientists can’t accurately predict when and where a slide might occur, they do know that today more people are living in places where landslides have happened.

“The issue of landslides in particular is a safety issue,” said DJ Gerken, of the Southern Environmental Law Center, which has applied state hazard mapping data to tax parcel information.

The Southern Environmental Law Center is advocating for a state law based on the hazard mapping data that would require minimum building and grading standards on steep slopes.

Gerken said the effort should focus on regulations and public education.

“It’s one, where you know there is a risk, putting that information into the hands of people who are building, who are buying or who are living here,” he said. “And two, making sure that they get the kind of engineering help and expertise to build appropriately. Engineers will tell you they can build in these circumstances, but recent experience in the mountains tells us that doing it the right way makes a big difference, and doing it the wrong way can cost people’s lives.”

The center, in an effort to raise awareness and provide a guide for county planners, found 990 homes in the paths of potential landslides in Watauga County.

Officials there have made no changes to land development laws in response to the state’s mapping or the center’s investigation, said County Manager Rocky Nelson.

The county has put the state hazard maps on its Web site but has no plans to deliver warnings to homeowners.

Macon County, another county where mapping is complete has made no changes to land development laws — although the county is studying a comprehensive growth plan and the maps are available at the county land office.

Like Watauga, the county also has no process for delivering warnings to homeowners.

But some counties have taken steps to regulate steep-slope construction with an eye toward safety.

In Haywood County, a two-year-old law might become a model for the state.

Local control

The Donins’ house in Maggie Valley wouldn’t be allowed today without an engineering plan for grading the lot. But it was built a year before the new slope law.

Today standards are much higher: Twenty-eight times last year, inspectors with the county’s Erosion and Sedimentation Control office noted possible slope failures or slopes that were too steep. Most were minor problems — small hills or grades that were problematic for storm-water runoff into streams and creeks.

But in seven of those 28 cases, inspectors said life or property were potentially in danger.

Two have since been repaired and are no longer under a notice of violation, according to county records. Two are still in violation but are being repaired.

One was a project involving pre-slope law construction, where the county had no violation authority, and one was a broken retaining wall that didn’t rise to the level of a violation.

And one, Jeremy Inman’s house in the Little East Fork community, is tied up in a lawsuit.

Inman won’t let his two daughters walk out the backdoor for fear they’ll be hit by a falling boulder.

He hired a grading contractor to carve a house pad for a mobile home out of some family land with a view of Cold Mountain.

He had to move there after his old home was damaged by flooding in 2004.

Inman was working out of state for most of the time the contractor was working on his property. When he came back, he found a rock cliff a few feet from his back door.

He made the contractor cut a large bench at the top of the cliff to keep some of the debris left over from blasting from falling on his house.

Even with that measure, rocks the size of bowling balls still tumble off the hill.

The job was finished just as Haywood’s new law was going into effect. Although he got a county certificate of occupancy to live there, erosion inspectors in a report said the slope is dangerous and needs more engineering.

Inman, a grader by trade, has access to equipment and would like to clean the site up. But he can’t because he sued his contractor, and his lawyer said to leave the site as it is.

But the problem behind his house, as bad as it is, doesn’t bother him as much as the rocks and debris the contractor piled along his driveway.

He estimates the side of the bank has dropped about two feet in the last year. Some of the boulders are aimed right at his father’s house across the road below.

“I mean that is a straight shot right into his living room,” he said. “It scares him to death.”

Inman’s house site, like the Donins’ wouldn’t be allowed today.

Haywood like most other WNC counties saw an uptick in mountainside development during the last 10 years.

The hot economy put second and even third homes within reach of more people and those people wanted mountain views. The more affordable land was higher up the mountain, not down in the valleys or towns.

Haywood caught on to this trend, and in 1988 adopted its own version of the N. C. Sedimentation Pollution Control Act. The move gave the county more control over land disturbing activity.

When county leaders in 2006 decided to take the law a step further and regulate steep-slope development, they tapped erosion office Director Marc Pruett to write the ordinance. A year later, Haywood became one of the first counties in the region to regulate mountainside cut-and-fill construction.

The decision to move forward with a local law came after a house collapsed in a Maggie Valley landslide, killing a woman inside. A leaking water pipe inside the hill above the home was suspected in causing the slide.

The law sets out minimum standards for soil compaction on subdivision roads and requires permits for slope cuts that exceed a 1-by-1 foot ratio, fill slopes that exceed a 1 ½-by -1 foot ratio or slopes greater than 40 feet.

To get a permit, the developer has to submit a slope construction plan created by an engineer.

Pruett’s office issues the permits and County Engineer Mark Shumpert inspects projects to make sure the construction meets the requirements in the law.

To date, no permitted artificial slopes have failed, Shumpert said.

Pruett said the move has been good for Haywood County — a view echoed by home builders. “We feel like we may have made a difference in the quality of construction on some of the steep areas, “ he said. “We want properties that are developed today to be safe and stable from now on. I want the Realtors to make money 30 years from now, 50 years from now, on properties that are well-built today.”

Inman agrees. And he said he supports regulations on slope development.

“It needs to be taken care of or people will wind up with just what I’ve got here— a mess,” he said.

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