Elk Grove Village is a step closer to completing engineering and environmental impact studies for the Busse Woods Dam modification project, aimed at alleviating flooding along Salt Creek in Cook and DuPage counties.
The village board Tuesday night approved spending $179,700 to immediately begin the phase two engineering study, which involves preliminary design, surveying and modeling of the Busse Woods Dam's operational scheme.
"We will get some assistance on the cost of the study," Mayor Craig Johnson said. However, village officials decided to start and will ask affected communities to chip in later.
Salt Creek flooding affects as many as 20 communities, most in DuPage County, such as Addison, Elmhurst, Itasca, Roselle and Wood Dale. Johnson has been working with the leaders of those communities to share in the estimated cost for the dam modification, which could be between $2 million and $5 million.
Johnson said the study will help determine the total cost of the project and help identify the environmental impact of modifying the dam.
The Busse Dam modification project is the result of a feasibility study conducted by the village last year after a proposal by the Friends of the Forest Preserves of Cook County.
The proposal suggested building an adjustable dam to replace the main dam at Busse Woods Reservoir -- built in 1976 to contain floodwater primarily from DuPage County -- as an alternative to an earlier proposal to expand the reservoir capacity.
A group of Northwestern University engineering students came up with the alternate solution for the Friends.
The reservoir was designed to hold water in the forest preserves, but the water often floods homes, businesses and heavily traveled roadways such as Devon Avenue.
The idea is to manually lower the level of Busse Lake, which feeds into Salt Creek, before heavy rainstorms so the reservoir can hold more water, which could then be released at a slower pace. To do that, the dam, located off Cosman Road, would have to be modified because it is locked and welded at its lowest elevation.
With heavy rainfall, the water level in the reservoir rises about a foot, which then gushes downstream at roughly 200 cubic feet per second. Salt Creek itself has capacity to hold 1,000 cubic feet of water per second before it floods.
Officials would lower the dam when it starts to rain to allow the creek to get to 1,000 cubic feet per second quickly. When the creek reaches its capacity, the dam would be raised to contain excess stormwater.
The environmental and engineering studies could take nine months to a year.
"This is really the big study to get us where we need to be to go out for bid and look for grants," Johnson said. "Our hope is we might be done early enough to start looking for bids next fall with construction in spring 2014."
Johnson initially had hoped to get the modified dam up and operational for fall 2013.
"It's a year later than I wanted," he said. "The board is committed to make sure that we get moving on this. This is a project that's long overdue. This is a high priority to the village. This board is ready to spend $30 million to $40 million on flood mitigation in the business park and throughout the community (including residential stormwater management)."