County: Armstrong Park reservoirs, pumps ready to handle next big storm

A $12.5 million project at Carol Stream's Armstrong Park, designed to protect homes from flooding, should be finished by mid-August, DuPage County officials said Thursday.

"The light at the end of the tunnel is there," county board member Jim Zay said of the high-tech system of pumps, sensors and reservoirs that will redirect floodwaters from homes that have historically been damaged.

After more than a year of work, most of the remaining projects have to do with aesthetics: Crews will be planting grass seed and putting down erosion blankets on either side of the park's trails, which have been repaved. A parking lot will get new asphalt after serving as a staging area for heavy-duty construction vehicles.

The county's stormwater employees also are working with manufacturers to get trained on how to control the pumps.

Since the county broke ground on the project in June 2014, neighbors have had to contend with an obstacle course of bulldozers and other big equipment at the park district site on Illini Drive. One particularly tricky part was installing 60-inch siphon pipe, normally done in a straight line, but in this case in a U-shape to get around utilities and homes, said Anthony Charlton, director of the county's stormwater management department.

"We certainly appreciate the patience of neighbors around us," Charlton said.

Here's how the system will work:

Rising waters in Klein Creek will spill, by gravity, over a wall into an L-shaped, smaller reservoir of two at Armstrong, creating a pool. Depending on how fast the water is flowing, up to two pumps will go live, capable of operating on their own or by remote control.

The county will get a notification that the pumps - churning out as much as 23,000 gallons per minute - are preparing to activate.

"We take advantage of technology, but we make sure there's a human backstop," Charlton said.

The pumps will push the water into the bigger reservoir, which had to be raised "because the groundwater was pretty high," Charlton said.

From there, water will funnel into 2,200 feet of 60-inch siphon pipe under Illini Drive, Indianwood Drive, Thunderbird Trail and, finally, a new swale that empties into downstream Klein Creek (with two private properties in between).

That process - storing stormwater and slowly releasing it back into a part of the creek that can handle it - is designed to shield homes near Armstrong Park from flooding.

"It is very successful at keeping the water out of people's homes," Charlton said.

What it likely won't do is eliminate flooding on streets during downpours, Charlton said.

That's what happened early last month when neighbors complained that Illini Drive flooded when 4 to 5 inches fell over the area despite the work at Armstrong Park.

Standing water on the roads long has been a problem there because of drainage issues, Charlton said.

"Because it's so flat, the topography, the water sits there," Assistant Village Engineer Bill Cleveland said.

At the time, the pumping station wasn't complete at Armstrong. Crews are currently about a month behind schedule because of the wettest June in Illinois history. The ground was too soaked, for instance, to install concrete mats on the inside of the reservoirs to keep the soil from eroding, said Zay, who lives in Carol Stream and heads the stormwater management planning committee.

"If we had another event, I'm confident that we could run the facility at 100 percent," he said.