Could a new retaining wall fix Columbia Parkway landslide problem? And how much would it cost?

Posted at 2:11 PM, Feb 21, 2019
and last updated 2019-02-21 14:16:39-05

CINCINNATI — It could cost the city up to $10 million to put in place a permanent fix to continued landslides spilling dirt and debris onto Columbia Parkway.

In a Feb. 15 memo, released Wednesday, City Manager Patrick Duhaney outlined the current state of his administrations' efforts to address what has been a road safety hazard for decades and a problem that seems to be increasing in frequency over recent years.

"Cincinnati's topography makes it one of the most beautiful cities in the Midwest," Duhaney wrote in the memo to Mayor John Cranley and City Council. "However, it also makes the city, its residents and its infrastructure susceptible to one of nature's most damaging natural events — landslides."

Over the last 14 months alone, the city has spent more than $145,000 in clean-up costs managing landslides along the parkway, Duhaney said.

It is the city's Department of Transportation and Engineering's responsibility "to monitor known areas of landslide activity and implement mitigation measures where the greatest benefit can be achieved," Duhaney wrote.

RELATED: This NKY road is closed due to landslides, too

Beyond consistent "monitoring" and "mitigation," Duhaney said "(o)ne permanent solution would be to build a new, higher wall on the north side of Columbia Parkway." But it could be a solution that just leads to new problems.

First, it would not be cheap. The new wall would cost roughly $1,000 per lineal foot of wall. With 9,700 feet of retaining wall along the parkway, that totals to $9.7 million.

That cost does not include tree and vegetation removal that installing a new retaining wall would also require, which Duhaney said could lead to further landscape disruption and instability, causing landslides in new locations along the parkway's northern edge.

And then there's the traffic headache the construction would cause.

"Additionally, any wall construction will introduce lengthy delays as access uphill is extremely limited, and construction and staging activities will have to take place from the parkway," Duhaney wrote.