Converting a degraded quarry into a community asset Ted Gray, P.E., CFM, CPESC Engineer/Eco-Hydrologist Living Waters Consultants, Inc. Burr Ridge, Illinois
he Jelke Creek Bird Sanctuary is a 239-acre area located in the Village of Sleepy Hollow, Kane County, Illinois. The site was purchased by Dundee Township in 2000. The acquired open space is bordered by 2,000 feet of Jelke Creek to the west, and residential subdivisions in other areas. Jelke Creek contains several desirable fish species as well as a variety of freshwater mussels. However, the value of Jelke Creek and the newly acquired Bird Sanctuary were compromised by historic aggregate mining activities. Approximately 120 acres or 50% of the project site had been disturbed and degraded by quarry activities. Moderately eroding slopes occurred along approximately 4,300 linear feet of the project perimeter. Typical conditions included 2:1 (H:V) or steeper unvegetated areas with heights extending to 20 feet. Sheet, rill, and/or gully erosion was common throughout the area. Soil-stabilizing
Quarrying disturbance included removal of topsoil, excavation of aggregate resources, and truck hauling. Unstabilized spoil piles of sand and gravel were common. Moderately eroded slopes ranged up to 20 feet in height. During flood events, stormwater runoff from the site contributed to pollution impacts at downstream Jelke Creek. 112 APWA Reporter
August 2012
vegetative cover was lacking due to a lack of organic matrix in the topsoil. Three degraded onsite ponds contained over 2,000 linear feet of eroding banks. Despite permeable soils, due to disturbance and compaction, silt-laden runoff would discharge through the gated south entrance toward Jelke Creek during flood events. Water quality impacts included siltation, sedimentation, nutrient enrichment, and habitat degradation extended downstream to Jelke Creek.
application of environmentally sound restoration engineering techniques within the context of a comprehensive site evaluation. Living Waters Consultants was hired to provide stormwater design, final engineering plans, ecological design, permitting, bidding assistance, construction observation, grant acquisition assistance, and ongoing maintenance and monitoring inspections. The lowest qualified bidding contractor, G.A. Blocker, Inc., was well-suited to large-scale, earth-moving projects.
Project Summary Project Goals Primary goals of Dundee Township for the Jelke Reclamation Project included improving water quality and reducing flooding from the degraded site. Project engineers determined this could be accomplished by retaining as much rainwater onsite as practicable through storage, infiltration and retention. Reducing offsite runoff would reduce the discharge of pollution into Jelke Creek, increase infiltration, and increase groundwater recharge. Groundwater recharge could help to protect regional groundwater aquifers as well as stream hydrology and ecology. Converting the eroding site into stabilized areas with deep-rooted native vegetation was considered essential to accomplish project goals. In addition, Dundee Township sought to improve recreational opportunities for the community.
Final Engineering and Construction Final engineering included the
Best Management Practices (BMPs) installed over 120 acres of degraded Project Area included the following: •
Conversion of 40 acres of eroding berms and stockpiles into stable slopes supporting native plantings;
•
Seven wetland filtration basins totaling 18.2 acres in area;
•
Conversion of one existing pond into a naturalized detention basin 0.5 acres in area;
•
Eight biofiltration swales totaling 3,670 linear feet;
•
Eight terraced swales over 4,000 linear feet in combined flow path length;
•
Forty-nine rock checks;
•
Five sediment forebays;
•
Over 875 linear feet of natural log toe and/or log habitat structures;
•
111 acres of native plant seeding;
•
3.6 miles of walking trails.
