Anyone that’s had to navigate the construction obstacle course on Summit Street over the last year knows all too well that the City has a major transportation improvement project on its hands.
But the Summit Street Project is more than a one-trick pony.
It turns out that where the rubber meets the road is also where water hits the pavement — and how that water gets handled can have a big impact on water quality and drainage in area creeks and streams.
It’s not surprising that a project the size of the Summit Street Project has a lot of layers but water quality may not be as obvious as some of the others so I wanted to pass along a description of those water benefits that the City Engineer put together.
It’s another great example where we’ve tried to bundle as many community benefits as possible into a project anytime we’re making investments in the public infrastructure.
That’s a good business practice that’s become standard practice for the City Engineering group — which is great news for the Kent community.
By: Jim Bowling, PE – Deputy Service Director/Superintendent of Engineering
It’s hard to imagine that a road improvement would also provide a significant improvement to the environment, but that is what we are doing on Summit Street. Increased storm water run-off and pollution go hand in hand with the addition of new pavement. While we are adding new pavement with the Summit Street Project, we are also building features that not only mitigate those increases, but take the peak runoff and pollution levels to new lows.
We are able to reduce the peak run-off and pollution by significantly expanding an existing storm water wetland. The expanded wetland is being constructed on both sides of Campus Center Drive south of Summit Street. When completed the wetland area will be over 2.5 acres divided by Campus Center Drive. Included in the expanded wetland, there will be 0.8 acres of micro-pools and forebays (wet areas) and the remaining area will be planted with wetland seed mixes, 885 perennials, 198 shrubs and 36 trees.
The combination of wet areas and wetland plantings will provide significant water quality benefits to storm flows that drain to Plum Creek and the Cuyahoga River. The wetland will help reduce concentrations of Total Suspended Solids (TSS), metals and dissolved pollutants such as phosphorous, nitrogen and chloride. While current ODOT and OEPA regulations would require us to treat 12 acres of drainage area, with the help of Kent State University, we will be treating 57 acres of drainage area. That is 4.75 times more than the minimum required.
In addition to the water quality improvements, we took the opportunity provided with the project to reduce the risk of downstream flooding. The storm flows from this area drain through a significant residential area on its way to Plum Creek and the Cuyahoga River. This residential area has had a history of flooding for as long as can be remembered. Therefore, we again went beyond the minimums required and increased the storage volume in the existing wetland by over 100%. This increase will reduce the chance of downstream flooding from 10% per year to under 1% per year.
The reduction in downstream flooding and the improved storm water quality from the expanded wetland will be experienced for decades to come. This shows that it is possible to help improve our environment while still solving some of our worst traffic congestion and safety problems.