By Kim Piekos
After more than three months of work this summer, the Walden Ravine restoration project has been completed.
Most of the attention in this $1 million venture was focused on the north side of Walden Ravine by Ringwood Road. Problems ranging from a collapsed headwall that allows water to move and the collapsing brick lining of the culvert under Ringwood Road signaled to the city that attention was required.
“This was truly a very necessary project,” says Jim Lockefeer, assistant to the director of public works, of the work on Walden Ravine. To slow stormwater down and improve water quality, three rock riffle pools were added to the north side. “These pools allow sediments to fall to the bottom of the pool and keep the rest of the water moving effectively,” says Jim Lockefeer, assistant to the director of public works in the City of Lake Forest. “This was truly a very necessary project.”
The south side of the ravine by Ringwood Road – which reopened Aug. 26 to cars, bicyclists and others with new curbs and other improvements -- also required some improvements, specifically improving the slope ratio and ensuring that water would move well through that area. “We don’t want a sheer cliff,” Lockefeer explains. “There was significant erosion that formed its own drainage swale, potentially creating an unstable area. “ A special ravine seed mix of native plants featuring long roots was developed and planted along the banks of the ravine to ensure stability.
Walden was the name of Cyrus McCormick Jr’s estate, which spread across more than 100 acres. It has been mostly razed, save for the stables off Westleigh Road that have been converted to a residence. Walden Road is a private road east of Ringwood that partially borders its namesake ravine, as does Walden Lane to the south. The 20 ravines in Lake Forest, carved by streams from 12,000-year-old receding glaciers, carry stormwater to Lake Michigan. “Ravines are incredibly significant to Lake Forest,” explains Lockefeer. “They are servicing natural watersheds that convey the water to the lake. Without them, millions of dollars worth of storm sewers under the ground would be needed.” During the summer months of 2017-2018 along with this year, the City of Lake Forest evaluated local ravines to determine how healthy and stable they were. College interns studying civil or environmental engineering trekked through each ravine, dropping points to record bank heights and ravine bed grading. “Though 90 percent of the ravines are privately owned, the city has a vested interest in them given their role in water management,” says Lockefeer. “We started looking at where the city might have some public ownership, where roadways may be impacted, storm sewer infrastructure and easements.”
The inventory and evaluation program, which used drones at times to record video of potentially problematic ravines, identified two ravines that needed restoration along with Walden: Rosemary and Rockefeller/Loch Lane. The Rosemary Ravine was completely restored in 2020, and the ravine near Rockefeller Road and Loch Lane, located near the Villa Turicum neighborhood, is scheduled to be designed in 2022 and restored in 2023. “The Rockefeller/Loch Lane project has eroding storm sewer infrastructure stemming from the roadway that needs to be addressed,” explains Lockefeer.
The City of Lake Forest employed Bleck Engineering, a Lake Forest-based company, to design the Walden Ravine restoration, and V3, a construction contractor with extensive experience in stream-bank stabilization.