A section of the North Branch Trail extension was submerged in water Friday. View Full Caption DNAinfo/Alex Nitkin

LABAGH WOODS — The newest section of the North Branch Trail doesn't just follow the North Branch of the Chicago River — it hugs against it. For much of the 1.2-mile stretch, the lazy current runs less than a stride's length from joggers' feet.

In at least one part of the trail, last week's rains closed that distance, and then some. By Friday, the lowest point along new trail — where it dips beneath Cicero Avenue and the Edens Expy. — had become a lake.

The flooding did not surprise leaders of the Cook County Forest Preserves, who on Aug. 12 will celebrate the completion of their two-year project to extend the trail from downtown Edgebrook all the way to Gompers Park, 4222 W. Foster Ave., in Mayfair.

In order to meet the 8.2-foot height clearance required below the highway, workers had no choice but to dig through a floodplain in the Labagh Woods, already "one of the wettest sites we have" among the 70,000 acres of county-managed forest, forest preserves spokeswoman Lambrini Lukidis said.

"We looked at a number of options, and having the trail go underneath really is the safest way for pedestrians," Lukidis said. "So we leave it up to trail users to expect some segments to potentially have flooding after it's been raining."

Signs warn cyclists of potential flooding in low-lying areas of the North Branch Trail. [DNAinfo/Alex Nitkin]

Flooding can be common throughout the 300-plus miles of trail that traverse the preserves, and officials try to warn users however they can, Lukidis said. In the Labagh Woods, they erected "caution" signs on each end of the highway crossing.

And the North Branch Trail's deep reach into the city doesn't mean it should abide by special grooming standards, she added.

"The Forest Preserves aren't a city park district — they're a vast expanse of open space and wilderness, and there is wilderness in Cook County," Lukidis said. "So there should be an expectation that sometimes people will be inconvenienced by natural factors."