Preliminary results from testing on the rain gardens the city of Columbus installed in Clintonville show they seem to be effective in reducing stormwater runoff into streams that feed the Olentangy River.

Jay Martin, an Ohio State University professor of ecological engineering who has been monitoring the rain gardens with a team of nine other researchers, discussed his findings during a presentation last week at the Whetstone branch of the Columbus Metropolitan Library.

Martin said his team has a contract with the city to monitor water quantity and quality from rain gardens and determine whether the project is creating new habitats with different types of birds and insects and how the neighborhoods are affected by the gardens, including home values.

"They put monitors in Adena Brook that have microphones in them," said Laura Fay of the nonprofit Friends of the Lower Olentangy Watershed, which hosted the meeting. "They're listening to insects and birds."

The city is installing more than 400 rain gardens in Clintonville, part of its Blueprint Columbus program to reduce storm runoff and sanitary sewer overflows into waterways while improving water quality.

Columbus is spending $80 million in Clintonville on the rain gardens while also installing basement sump pumps, redirecting downspouts and relining leaky sewer pipes.

Martin said his team is monitoring three areas that drain into Adena Brook, which flows west into the Olentangy. The team also is monitoring a fourth in Beechwold, north of where the rain gardens were installed, for comparison. The team will gather data through 2022.

The city said the $1.1 million Ohio State monitoring contract runs from 2016 to 2023.

"We are looking at a whole slew of things," Martin said, including whether the rain gardens are helping to filter such pollutants as nitrogen and phosphorous that can cause algae blooms that harm fish, as well as sediments.

Fay said she believes the rain gardens will do what they were designed to do.

"They're not going to answer everyone's problems," she said, but they are a better alternative than the expensive tunnels the city was planning.

The rain gardens have had a mixed reception in Clintonville, with some residents finding them unattractive and disruptive to traffic, and others wondering if they will work.

Blenheim Road resident Patty Hartig, who lives near two rain gardens that bump out into her street, said she has gotten used to them and that they seem to work, absorbing rainwater and slowly draining. She said it appears the city is weeding the gardens and employing reflectors so drivers avoid them.

Clintonville Area Commission member Judy Minister said some residents have described them as looking like caskets.

Martin said what researchers learn in Clintonville will help as the city expands the rain garden program to North Linden next year. The city plans to extend the program into the Hilltop and the Miller-Kelton area on the Near East Side in 2021.

Leslie Westerfelt of Columbus' department of utilities, who serves as spokeswoman for Blueprint Columbus, the city's stormwater initiative, said work on the latest phase of rain-garden construction in Clintonville was completed earlier this year. The next phase in the neighborhood will likely begin in 2024.

Westerfelt said the city will begin gathering public input in 2021 for the next Clintonville phase, which will involve streets between Whetstone Park and Clintonville's southern border near Olentangy Street.

Public meetings will be held early and often, she said.

"We've learned some lessons in design consideration, implementation and in the way we engage the public," Westerfelt said.

As with the first phase, the city will consider public spaces where stormwater can be intercepted, slowed down and cleaned by the gardens, along with existing sewer infrastructure.

"There are lots of different factors" in deciding where to place the rain gardens, she said.

The city also will continue to work with property owners to keep excess stormwater from collecting around foundations, instead redirecting it into the streets where the sewer system can handle it, Westerfelt said.

Those interested in replacing their sump pumps may call 614-645-1253.

Funding for Blueprint Columbus is part of the Department of Utilities' regular budget, which comes from residents' sewer bills. Blueprint is a 30-year project, Westerfelt said.

Friends of the Lower Olentangy Watershed chairwoman Kelly Thiel said last week's event was part of the organization's ongoing interest in the rain-garden project.

"Because the Blueprint project was started in Clintonville, it particularly affects (the Olentangy River) watershed and impacts water quality," Thiel said.

"We understand not everybody likes how (the gardens have) been done, but we want to see what the data shows. We're always looking for alternatives to improve water quality."

ThisWeek correspondent Jim Fischer contributed to this story.

mferench@dispatch.com

@MarkFerenchik