Columbus Council has approved spending $1.3 million to stabilize two sections of the Chattahoochee River’s banks that have collapsed along the city’s whitewater course.
A section that collapsed in March behind Chase Apartments, just north of City Mills, has been stabilized temporarily but needs permanent stabilization work, Deputy City Manager David Arrington told councilors. At another section north of that site, about 600 feet of bank has collapsed, threatening the Chattahoochee RiverWalk in that section.
To date, the city has spent about $208,000 stabilizing the section behind Chase Homes, Arrington said. But it will take another $600,000 to permanently stabilize that section and about $715,000 to address the section to the north, just beyond the 23rd Street Pavilion.
Councilor Skip Henderson asked Arrington if the change in the river from the still water of the old mill ponds to the current constant flow might have caused the damage. Arrington said it could be a minor contributing factor but not a primary cause. He pointed out that the slope failure on the Chase site began before the City Mills Dam, just downstream, was breached.
Arrington said the record rainfall the city has seen this year is likely a factor, and reminded councilors that riverbank failures are a fact of life and always have been along the river. City Engineering Director Donna Newman confirmed Arrington’s assessment.
“If you go back and look at the historic records of the city from the time it was incorporated, you’ll see references to slope failures on the river,” Newman said. “So we are going to see things like this in the future.”
In January 1858, for example, a chunk of the Phenix City (then Girard) bank over an acre in size collapsed into the river, taking one or two houses with it and damaging a mill nearby, according to John H. Martin’s history book, “Columbus, Georgia, 1827-1865.”
Arrington said there are two stages of addressing the collapsed banks. First there is stabilizing the area to halt the erosion and make the area safe. But permanent stabilization will require more extensive landscaping with deep-rooted plants in addition to the grass that has been put down behind Chase Homes, he said.
Mayor Pro Tem Evelyn Turner Pugh suggested that because the RiverWalk is so important to the city and its quality of life, some private entities might want to contribute to this kind of maintenance.
“I’m hoping that some people listening today are some of our corporate citizens. We talk a lot about public-private partnerships,” Turner Pugh said. “We’re having more and more people coming down the river than we used to, and we want them to keep coming.”
A short section of the collapsed area is close enough to a Georgia Power transmission line to threaten its stability. The utility will pay for repair of that section of the collapse, Arrington said.
The slope failure phenomenon that precedes the riverbank collapse can be visibly detected, and has been, before the collapse, Arrington said. With that in mind, he said he wants the city to implement a Slope Stabilization Project in the fiscal year 2015 budget to be more proactive in stabilizing sections before they fail.