This time, the program will use porous asphalt streets, porous turf parkways and underground temporary detention areas to help cut basement and street flooding in east Kenilworth neighborhoods and to help clear pollutants from surface water before it enters the sewer systems, officials said.
Kenilworth is one of the first communities in the Chicago area to use the porous parkway, temporary water detention and asphalt street technology in a flood-control plan, Village President Bill Russell said.
"I think this will be a watershed program, no pun intended, that will have an effect that will go way beyond Kenilworth," Russell said.
The Illinois Environmental Protection Agency is aware of only one other community, Carbon Cliff, Ill., that has committed to using porous streets as part of a flood and water-control policy, IEPA spokeswoman Kim Biggs said Dec. 1, though she cautioned that the department only has records from communities that receive EPA funding for such projects.
Porous pavement was more apt to be used in parking lots, she said.
"It's a new best management practice," Biggs said. "We weren't even looking at permeable pavement 20 years ago."
Unlike Kenilworth, Carbon Cliff, a village of slightly more than 2,000 people near East Moline, is rebuilding its deteriorated streets with permeable paving technology, according to a brochure put out by the village.
Kenilworth officials originally planned to use permeable pavers as part of their flood-control strategy, Russell said, but in the spring of 2014, residents told the board they were worried that pavers and rain gardens would change the look and nature of Kenilworth.
Russell said in August of 2014 that some residents were also concerned about how the plan would treat Kenilworth's parkway trees.
Russell and Kenilworth Village Manager Patrick Brennan said in August of 2014 that the village board put the plan on hold to regroup. In 2015, village trustees decided to go with porous asphalt and porous turf parkway segments, Brennan said Nov. 30.
In November, trustees agreed to seek bids for a general contractor for the project, Russell said.
Bids should go out in mid-December and be back in village hands in January, Brennan said. If the board chooses a contractor at that time, construction could start early in 2016, he said.
He said the village won't have a solid cost estimate until after they get both the returned bids, and a preliminary engineering estimate, expected within the next two weeks.
"Our rough guess right now is between $6.5 (million) and $7 million," he said.
Kenilworth will replace sections of Cumberland and Melrose avenues, and Roslyn Road, all east of Cumnor Road, with permeable asphalt, which will sit atop multiple layers of crushed stone, according to village officials.
Officials said parkway sections along those streets will also be rebuilt to soak in surface water and filter it through specially mixed, or "amended," absorbent soil and gravel to help separate pollutants from the water, and send it more slowly into Kenilworth's sewer systems.
The streets will be built over new storm sewers, which will separate storm water from east Kenilworth's existing combined sewer system. The new sewers, while not themselves part of the Green Streets project, are part of the overall Kenilworth 2023 flood control program developed after 2008 flooding filled village streets and basements with water and sewage, Brennan said.
"We did an analysis of the east side of Kenilworth, which we knew had a flooding problem and deteriorated infrastructure," Russell said. "There are lines that are original equipment. It's untenable that a community such as ours would have infrastructure that deteriorated."
Most street and parkway work will be paid for with the remainder of a 2013 $9.75 million bond sale, Brennan said.
Roughly $2 million has already been spent on water main improvements on the west side of town, he added. Some funds for the Cumberland-Roslyn-Melrose storm sewer project will come from a Metropolitan Water Reclamation District partnership grant of $993,000 for green infrastructure improvements.
The combination of permeable paving and parkways will help improve the efficiency of the new storm sewers, an engineer with the project said Nov. 25.
Joy Corona, water resources project manager for Lake Forest-based Bleck Engineers, said the combination of street and sewer projects "should eliminate sanitary sewer backup, especially compared to the current combined sewer system."
Corona said street pavers are more durable than porous asphalt, but that asphalt is less expensive and will last for many years.
T. Carter Ross, vice-president of communications for the Maryland-based National Asphalt Paving Association, said that porous asphalt can usually last as long as regular asphalt with the right care, a life of between 10 and 20 years, depending on how heavily used a street is.
Ross and Kevin Burke, executive vice president of the Springfield-based Illinois Asphalt Paving Association, echoed Biggs in saying few communities have turned to porous paving technologies for streets.
"The major user in Illinois has been the city of Chicago with their green alley program," Burke said. "There's been a lot of discussion about porous pavement, but I'm not aware of any large-scale programs."
"I think it's very exciting. There are some challenges in construction, because a lot of the failure in these types of systems comes when the construction isn't done right," Corona said. "Nobody wants to be the first (to use a new technology) … but it might inspire other communities."
©2015 Pioneer Press Newspapers (Suburban Chicago, Ill.) Distributed by Tribune Content Agency, LLC.
