Hamill Road in Hixson is one of many Chattanooga roads that has what's called "slope failure." The city put up a sign on Hamill encourage drivers to exercise caution in the area.Chattanooga has $1 million to begin addressing more than a dozen area roads that pose a potential public safety hazard because of what is known as "slope failure."
That's far short of the $14 million needed to fix all of the problems, but it's a start, officials said.
In all, nearly 20 problem spots have been identified on 14 roads that could be at risk for slope failure. That can include caving in, having part of the road slide off a hill, or rocks falling onto the road.
The worst problem spots are a portion of Hamill Road that skirts North Chickamauga Creek and an area of Lake Resort Drive near Chickamauga Dam, said Ariel Soriano, manager for engineering, design and construction for the Public Works Department.
The city will target the worst areas first, with work beginning in the spring, Soriano said.
Soriano said $1 million could be stretched to address Hamill Road or Lake Resort Drive, but probably not both.
"It could handle a small project or a portion of a large project," he said.
Several roads in steep or mountainous areas across the region experienced slope failures last year, from Signal Mountain Boulevard to U.S. Highway 64 and, farther away, Interstate 40 above Knoxville.
In December 2009, pressure from water caused a portion of U.S. Highway 127, also called Signal Mountain Boulevard, to collapse into the valley below.
BY THE NUMBERS• $14 million: Amount needed to fix all slope failures within city limits• $1 million: Amount in capital budget this year for fixes• 14: Number of roads in Chattanooga experiencing slope failuresSource: City of ChattanoogaSlope failure presentation (PowerPoint)
The same year, two major rock slides in the Ocoee Gorge kept U.S. Highway 64 closed for months. There were rock falls on Cummings and Scenic highways on Lookout Mountain and two mudslides on the W Road over the winter and spring.
Traffic was disrupted for days or months as road crews worked to restore the roads. No one was killed in any of the incidents.
Following a spate of such problems, city officials said they needed to address the problem for public safety and liability reasons.
The Chattanooga City Council put $1 million into the 2010-11 capital improvement budget to address slope failures.
Soriano said he is glad the city took this step.
"This is the first time the city has really targeted these issues," he said.
CAUSES OF FAILURE
Vanessa Bateman, civil engineering manager for the Tennessee Department of Transportation, said slope failures are created by ice forming in the cracks of the ground or rock and then expanding.
"Primarily, our enemy is water," she said.
The number of slope failures last year seemed higher than normal, she said, but she noted that dry winters resulted in fewer failures for several years before that.
POTENTIAL SLOPE FAILURESPortions of these roads risk crumbling off the sides of hills because of steep terrain or nearby waterways:• Agawela Drive• Big Ridge Road• Granada Drive• Hamill Road• Lake Resort Drive• Lower Mill Road• Main Street extension• North Chamberlain Avenue• North Crest Road• North Terrace Road at Belvoir Road• North Terrace Road at Moore Road• Old Hixson Pike• Ridgewood Drive• River Street near Girls Preparatory School• Rose Terrace• South Crest Road• South Terrace Road at Moore Road• Waterfront Drive• Youngstown RoadSource: City of Chattanooga
"We just had a nice lull for a while," she said.
The only thing that can be done is to monitor known hazardous areas constantly to see if they are close to failing, she said.
In the region, the state plans to monitor several areas over the winter including Interstate 24 over Monteagle Mountain, state Route 30 through Bledsoe and Polk counties and U.S. 64 through Polk County, she said.
"So far, we're in December and we haven't had the failures we had last year," Bateman said.
COUNCIL BRIEFING
A month ago, Soriano told Chattanooga City Council members about roads in danger of falling off into nearby creeks, rivers or lakes. He estimated that fixes would cost about $14 million in all.
The roads are open, but in one instance, on Hamill Road, warning signs have been placed on the side of the road alerting drivers to slow down.
Soriano said Hamill Road could be a multimillion-dollar fix, while Lake Resort Drive could cost about $1 million. But he said no engineering studies have been conducted on any of the projects, so there are no exact cost estimates.
"Thank goodness we have some money available," he said.
The city will decide in January or February which of the two roads to tackle, he said.
Councilwoman Pam Ladd, who represents the areas where those two roads lie, said she never expected the city to be able to do both projects next year. But the city needs to continue allocating at least some money each year to address the slope failures, she said.
If that happens, many of the 18 projects could be addressed in a matter of years, she said.
"When you get down the list, a lot of those aren't million-dollar fixes," she said.
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