Some Aiken residents living in an area between Whiskey and Banks Mill roads soon will be learning more details about plans for the initial phase of the Whiskey Road Corridor Improvement Project, which will focus on stormwater drainage.
Johnson, Mirmiran & Thompson, Inc., a civil engineering firm also known as JMT, is preparing a design for a drainage system that is approximately 60% complete, said Aiken County Administrator Clay Killian.
It includes an open channel through which the stormwater will travel. On Whiskey Road, the channel will be near Mercy and Trinity United Methodist churches.
Along its path to Banks Mill will be the Elmwood Park, College Acres and Mallet Hill subdivisions.
Also in the area is the Wise Hollow drainage basin.
Easements will be needed to build the channel, and owners of the affected land “will all probably get a letter from me letting them know that somebody is going to be reaching out to them,” Killian said.
They could hear from county staff members and officials or representatives of JMT.
Killian expects the contact process to begin in early November.
“We're going to kind of take it slow,” Killian said.
Aiken County Council received an update on the progress of the Whiskey Road stormwater drainage system project from Aiken County Engineer Teresa Crain during the work session prior to the panel’s September meeting.
Crain said information needed to be obtained from surveys of the land between Whiskey and Banks Mill to complete the design, which is scheduled to be finished by July 2020.
JMT began working on the design in January 2018.
“There will be a series of four ponds, and there will be a channel connecting the ponds,” Crain said. “Runoff will go into the ponds and be released from them at a controlled rate into the channel.”
The channel will be around 100 feet wide and will include a maintenance trail and slopes.
After a major storm, water will fill a portion of the channel about 25 feet wide and after a smaller storm, the flow will be around 10 feet wide, Crain said.
The channel and the rest of the Whiskey Road stormwater drainage system will be designed to handle a 50-year storm event.
Typically, the South Carolina Department of Transportation and county stormwater drainage systems are made to deal with a 25-year storm event, Crain said.
Concrete and other manmade materials won’t be used a lot in the channel’s construction.
“It will be a natural channel with native grasses and maybe some shrubs on the side,” Crain said. “There is one section where it (the water) will be piped, but it will be underground where you won’t see it. That part will be made of concrete, obviously, but it will be a short section (between Powderhouse and Banks Mill).”
Under Powderhouse Road, there will be a culvert.
To accommodate it, a section of the road will have to be raised “a foot or two,” Crain said.
Water won’t be flowing continuously in the channel.
“It’s not going to be a running creek,” Killian said. “The ponds will only have water in them for a few days (after a storm).”
He added that one goal of the design is for the channel to have “gentle” slopes.
The cost of the channel and the rest of the stormwater drainage system hasn’t been finalized.
“The early numbers look like they are going to come in pretty good,” Killian said. “But I don’t have an amount yet that I feel comfortable sharing. We have $9 million in Capital Project Sales Tax IV (which was approved by county voters last November) for this project, and it’s possible it could come in within that budget.”