By Dedra Cordle
As the $1.8 billion city-wide effort to reduce sanitary sewer overflow problems through redirection and infrastructure improvements gets underway in Westgate, residents in another Hilltop neighborhood are starting to learn more about the projects that Blueprint Columbus has planned for their area.
On March 30, the Blueprint Columbus Outreach Team hosted a public meeting and open house at the Run the Race Center on S. Wayne Avenue to discuss the final design concept for the ‘Hilltop 4’ segment of the massive stormwater and sanitary sewer infrastructure improvement project.
According to Daniel Biru, a project manager with Korda/Nemeth Engineering Inc. who also serves as a consultant for the city, there are more than 80 green infrastructure improvements planned for Hilltop 4 whose general boundary is described as Eakin Road on the south, Wiltshire on the west, Sullivant Avenue on the north, Whitethorn on the east, and Hilltonia Park on the far southern end.
The vast majority of the green infrastructure improvements that are planned for the 350 acres that make up the Hilltop 4 segment will be rain gardens of similar size and design.
“There are 85 green infrastructure improvements that are planned for this region,” said Biru. “And of those 85 green infrastructure improvements that are planned for this region, 75 of those will be right-of-way rain gardens placed on city property, one bump-out rain garden, seven regional rain gardens on land bank owned property, and two pervious paver streets.”
Biru said that sloped rain gardens are the “most basic” design of rain gardens and they will be predominantly placed on streets with no curbs. For example, he said sloped rain gardens are slated on these avenues and roads: Clarendon, Rosedale, Safford, Springmont, and Whitehead.
One or two-walled curbside rain gardens will be installed on these roadways to help alleviate grade differences between the pavement and property lines: Burgess, Eakin, Eureka, Hague, Harris, Highland, Ogden, Mound, Terrance, Warren, Wayne, and Wheatland.
Biru said that motorists will not be able to park beside the two-walled curbside rain gardens but added that efforts have been made to install these two-walled rain gardens on streets that already have prohibited parking.
There will be two-walled rain gardens with step-out located on these roads: Eureka, Hague, Harris, Oakley, Mound, and Whitethorne.
There will be a bump-out rain garden placed on Amherst. Tiffany Conn, a Blueprint Columbus outreach coordinator said that while the bump-out rain gardens are the least preferred rain garden due to a design that “sticks out,” they serve a dual-purpose as they are also a good traffic calming measure.
The regional rain gardens, which are slightly larger than other rain gardens and allow for trees to be placed on top of them, will be located on the land band owned properties on these streets: Wayne Avenue, Oakley Avenue, Highland Avenue, Mount Street and Wayne Avenue, Safford Avenue and Oakley Avenue, Whitehead Road and Eureka Avenue, and Sullivant Avenue and Clarendon Avenue.
With the exception of the regional rain gardens, all of the other rain gardens will be limited in size.
“They cannot be any longer than 40 feet,” said Jeremy Cawley, project manager for the city department of public utilities sewer system engineering section.
All of the rain garden locations – which have been marked with “Future Rain Garden Site” signs by the city – are slated to be excavated sometime next year. The subsurface will be prepared by adding layers of soil and stone that are designed to filter stormwater. Native plants and mulch will make up the top layer of the rain garden.
Chad Kettlewell, an ecologist with Coldwater Consulting, said the native plants will have a deep root system to help stabilize the soil and, as they mature, fracture the soil to keep it healthy so the water can continue to get into the soil and get filtered properly as opposed to “clogging up” and creating flooding issues.
He added that the rain gardens will typically drain in 24 to 48 hours, which will reduce the chances of it becoming a mosquito breeding ground.
“If the rain gardens are holding water (beyond 24 to 48 hours) that means there’s something wrong with it and somebody needs to come along to deal with it,” he said.
Conn said rain garden maintenance will be on the city – not the residents.
“We will maintain all of this forever,” she said. “The city maintenance team will come out at least once a month to collect trash and do the weeding and to check the flowers and plants to make sure things are functioning properly.”
She encouraged residents to call the city if they believe the rain garden nearest to their location is not looking healthy or working properly.
In addition to the 83 rain garden locations, there are two pervious pavers streets planned for Richardson Avenue between Mound Street and Whitehead and on Eureka Avenue between Safford Avenue and Springmont Avenue. Pervious pavement is described as brick-looking concrete blocks that are designed for rainwater to seep between the cracks instead of running across the surface.
Joe Tribble, a civil engineer at Korda/Nemeth Engineering Inc. said pervious pavers are the most expensive of all the green infrastructure improvements and the most time consuming to construct as well. He said because the installation of the pervious pavers involves waterline work, there will be some limited water outages but residents will be given 24 hour notification before.
Cawley added that new waterlines will be installed during the process as well as new drive approaches and new sidewalks for these areas.
In addition to limited water outages, Blueprint Columbus officials say there will also be other impacts during the stormwater and sanitary sewer green infrastructure improvement program. They include the removal of several trees along the pervious pavers streets, the removal of some sidewalks, handicap ramps, streetlights and street signs, and the occasional fence that may be in the excavation area. The trees that are removed will be replaced with new trees and the infrastructure that is torn up during the green infrastructure improvement process will be replaced. Tribble said it will be up to the homeowners to replace and reinstall the fence.
Cawley said Blueprint Columbus’ Hilltop 4 final design concept is about 90 percent complete. He said that if “all goes according to plan” the city contractors could break-ground on the green infrastructure improvements in the spring or summer of 2024. After the project is complete, the city will begin working with homeowners on two of the other pillars of the city-wide initiative to improve the sanitary sewer overflow problems that have been plaguing the area for decades: lateral lining and roof water redirection.
That work, said Cawley, could begin in 2025 or 2026.
The Blueprint Columbus team said certain homeowners may be eligible for a new sump pump at no cost to them. Conn said the city does not usually install sump pumps in finished basement. For more information on that program, contact the Blueprint Columbus team at blueprintneighborhoods.com or at 614-645-1253.
Residents will still be able to offer their opinions on the placement of the rain gardens and the native plants they would like to see within the rain gardens via the website and phone number listed above. Conn said Hilltop 4 residents can reach out to the team if they feel the city missed a potential rain garden location.
The Blueprint Columbus project will address the sanitary sewer overflow problems in 17 neighborhoods. It will span two decades and cost roughly $1.8 billion. During the initial planning stages, the Hilltop area was designated as a high priority area as there were a significant number of basement backup incidences and the sanitary sewer overflow that discharges into Forest Creek/Scioto Run Big Run. It has been divided into four segments with the Westgate area – which was broken up into two sub-areas due to its size – defined as ‘Hilltop 1’ and the Highland/Harris area designed as ‘Hilltop 4.’
Blueprint Columbus will address the other areas of the Hilltop in the near future.