Cardno Environmental contracted to manage natural detention pond
by Melanie Jongsma
LANSING, Ill. (November 14, 2018) – A sunny, windless day seemed like a perfect opportunity for a controlled burn in a residential area, but the conditions proved to be problematic. Phragmites is a difficult species to burn anyway, and with no wind to fan the flames, the patch in the channel on the Villas of Lansing property never really caught on fire. Cardno technicians tried mowing the stalks and using the detritus as fuel for the fire, but without air movement, the flames were not strong enough to consume them. After about three hours, Cardno admitted defeat and decided to finish the job on a slightly windier day.
“It’s very weather-dependent,” said Chip Taylor a staff scientist in Cardno’s Engineering & Environmental Services division, and project manager for the work at the Villas. “Sometimes you just don’t get a good burn.”
The phragmites problem
Phragmites is an invasive species of wetland grass that is non-native to Illinois. It can grow up to 18 feet tall, and it spreads through both seeds and rhizomes. Because of its aggressive growth, it crowds out native plant species, impacting biodiversity and water systems. According the the US Fish & Wildlife Service, “Phragmites can also eliminate small intertidal channels and obliterate pool habitat that offers natural refuge and feeding grounds for invertebrates, fish and waterbirds. Phragmites can create a dense jungle of vegetation that native salt marsh birds, furbearing mammals and even deer cannot penetrate.” (Phragmites Q and A Fact Sheet) Phragmites thrives in low-lying marshy areas and is commonly found in forest preserves, along railroad tracks, and in roadside ditches.
During the development of the Villas of Lansing, a stormwater detention pond was installed adjacent to North Creek as part of the stormwater management system that serves not only the Villas but also the surrounding area. The detention pond is a “wet pond,” in that it was designed to permanently retain some water at all times. The north, shallow end of the pond is a federally protected wetlands, installed to replace the section of wetlands the builders developed into housing. The channel on the north edge of the pond was intended for overflow.
Because the Villas property abuts the forest preserve, where phragmites has not been controlled, the channel in the Villas became a natural depository for seeds blown from the forest preserve. In order to prevent the entire detention pond from being consumed by the invasive plant, and to preserve the sightline from the homes along the channel, the Villas hired Cardno to begin managing the pond and channel.
Effective eradication of phragmites involves a series of herbicide treatments that will kill both the plant and the rhizomes. Cardno began applying herbicide to the Villas’ phragmites patch in August, so the material they cut and burned today was dead, incapable of resprouting when falling to the ground.
Cardno will return to try to complete the burn whenever wind conditions and their project schedule allow. If the phragmites patch proves to be flame retardant, Cardno will simply mow and mulch the entire patch.
The Villas of Lansing is located at 186th Street and Oakwood Avenue.
The local branch of Cardno is at 6605 W Steger Road in Monee. For more information about the environmental services they provide, visit cardno.com.