Throughout 2007 staff and the Village Board discussed the possibility of undertaking a comprehensive Stormwater Management Plan (SMP). Staff recommended the Village Board support the goal of developing a SMP that would result in the Village’s storm sewers being capable of handling a 10-year rain event without discharging into homes, and that this protection is achieved within 10 years. Three phases to the project were identified:
- Phase I- Preparation of a model to be run under various rain scenarios. Determination if system can handle a 10-year storm.
- Phase II- Identification of system bottlenecks; potential improvements to bring the system to a 10-year capacity would be identified.
- Phase III- Design of improvements and oversight on implementation.
On June 5, 2008 the Village Board entered into an agreement with AB&H, A Donohue Group (AB&H) to complete the project. Over the last several years AB&H has worked with the Village’s Ad Hoc Sewer Committee to complete Phases I through II of the Stormwater study.
In 2009 AB&H completed Phase I of the Stormwater study. The Phase I report concluded that the Village’s sewer system could not handle a 10-year rain event without surcharging into basements. This conclusion was based on the assumption that the Village’s sewer system was currently in perfect working order and free from blockages or flow issues. A series of rain events were run through the hypothetical “problem free” system to determine if the system could handle a 10-year rain event. Virtually the entire system failed. Click here for the Phase I Report.
On June 14, 2012 the Ad Hoc Sewer Committee deemed the Phase II Report complete. The report was presented to the Village Board on August 16, 2012. A summary of the report findings may be found below. To read the full Phase II Report click here.
The Phase II model utilized updated topographic information, real rain scenarios, and all sewer pipe sizes. The report evaluated the use of surface storage (the use of the street to temporarily store stormwater for a designed period of time) as well as conveyance and detention methods to manage stormwater. The report concluded that in order to obtain a 10-year level of protection for the Village a combination of infrastructure projects would be needed. Utilizing only street storage the Village would increase its current level of protection during storms from a 2-3 year level of protection to a 4-5 year level of protection. This would be achieved through the use of gradual berms at each end of a block to contain water and restrictors be placed inside (underground) the sewers to control the release-rate of water into the sewer. It is estimated that this method of stormwater management will cost approximately $5.6 million. This method would provide protection to 73% of the Village during a 10-year rain event.
In order to obtain protection for the remaining 27% of the Village conveyance and detention methods must be used. These methods include increasing the size of various sewer pipes, creating new stormwater outfalls and installing detention ponds. The estimated cost to implement these improvements is $28 million.
On March 13, 2013, the Village Board held a public meeting to discuss the proposed improvements and to seek input from the public. Click here to view the video of this meeting. Click here to view the presentation from the meeting.
On April 2, 2013, the Village Board discussed the results of the study further and requested that additional information be provided at a future Board meeting regarding recommended pilot areas for street storage. On April 2, 2013 the item was tabled due to the pending election.
On July 16, 2013, Village staff presented the Ad-Hoc Sewer Committee’s recommendation to proceed with a Pilot Study for stormwater street storage and the Board authorized the staff to issue a request for Proposals (RFP) to secure an engineering firm to design the improvements.
On November 5, 2013, the Village Board awarded a contract with Gewalt Hamilton Associates to begin the design for the pilot area. The pilot area chosen is generally bounded by Devon to the south, Pratt to the north, McCormick to the east and Lincoln to the west.
On May, 15, 2014, a community meeting was held to discuss the pilot area project. The video of the meeting is available here.
For questions regarding the Stormwater Study please contact the Public Works Department at (847) 675-0888.