A wetland area near the Illinois side of Wolf Lake that was a mecca for birding as recently as a decade ago may reclaim some of its former natural glory by the end of this month.

Construction of a new water control system at Eggers Grove started at the end of May and was expected to take about a month.

“This used to be loaded with birds,” said Chip O’Leary, deputy director of resource management for the Cook County Forest Preserve District. “Now, you’ll be lucky to see a couple (of native waterfowl).”

The 240-acre woodland and wetland preserve sits at the Illinois and Indiana border along Interstate 90 and south of 112th Street.

The wetlands surround Wolf Lake, which drains into the Calumet River.

The $400,000 project is funded through various grants and is being overseen by the Cook County Forest Preserve District, The Nature Conservancy and Audubon Great Lakes.

“It was sort of an obvious site to do this restoration work,” said Bradford Kasberg, of Audubon Great Lakes.

He said the Calumet region, which stretches from Northwest Indiana to the Blue Island and Midlothian areas, is an important for many migratory birds, including the least bittern, black-crowned night heron and Virginia rail.

“This is their last respite before getting through the Chicago metropolitan area,” he said.

But much of the region’s natural wetland areas have been drastically reduced through the decades because of development, Kasberg said.

At Eggers Grove, the area was affected by the construction of a missile site in the 1950s during the Cold War.

O’Leary said soon after that construction engineers noticed how the site’s natural areas were affected and built a water control system.

It failed about 10 years ago, leading to the preserve’s degradation.

In order to be a suitable natural habitat the wetlands should have a cyclic pattern of being flooded and drained, he said.

But the wetlands in Eggers Grove had been consistently flooded leaving little chance for native vegetation to grow.

O’Leary said another negative effect was that mud was suspended in the flood water blocking any light from penetrating, which is important for plants and animals.

The deep, stagnant water became unsuitable for native plants and for waterfowl nests.

The new water control system will allow forest preserve workers to control the opening of three gates to drain the wetlands as needed after heavy rains, or leave closed during drought conditions.

“We think it’s going to make a pretty big difference,” Kasberg said.

He said a similar project was done at Big Marsh just east of Lake Calumet and had helped to double the amount of “secretive” marsh birds Audubon volunteers are monitoring.

The marsh birds are secretive because they can be elusive to bird watchers as they usually occupy areas inaccessible by foot.

But Eggers Grove offers opportunities to see the birds from a distance as the site includes public access parking, a trail and picnic areas.