The project was a collaborative effort between DuPage County Stormwater Management, the Village of Carol Stream and the Carol Stream Park District to reduce flooding for approximately 60 properties in the surrounding neighborhood that had experience severe flooding.
The project is a two-reservoir system that intakes water from the adjacent Klein Creek during flood events. The first reservoir in the system is a smaller gravity-operated reservoir that takes in water over a fixed, concrete weir. Once elevations reach a certain height in the smaller reservoir, they are pumped to the larger reservoir. Each of the two large pumps can pump at a rate of 20,000 gallons per minute. Once elevations in Klein Creek recede, the larger reservoir is dewatered through a 60-inch siphon that bypasses that surrounding neighborhoods and distributes the water back to the creek approximately half a mile downstream. In total, the reservoirs have a capacity to hold nearly 113 acre-ft of floodwater.
The project also offers environmental features with native plants treating the floodwater in both reservoirs, as well as a wetland feature designed to collect and treat standing water outside of the basins. WBK staff worked with DuPage County Stormwater Management to design and permit the flood mitigation project. Specifically, WBK staff prepared the design engineering and construction documents for the two flood control reservoirs, one of which is designated as a small-size Class I dam, two overflow weirs with integral pedestrian bridges, along with the overall site design for the project.