Wilmette Neighborhood Storage Project - An Urban Flooding Relief Project is the Largest Capital Project in the Village's History

The Village of Wilmette is a northern suburb of Chicago and is located adjacent to Lake Michigan. There is a major watershed divide within the Village; one watershed drains east to Lake Michigan and the other west to the North Branch of the Chicago River. Runoff in the western watershed is collected by regional trunk line storm sewers that outfall to a large stormwater pumping station at the River. The historic storm sewer conveyance system is undersized compared to modern standards and the western portion of the Village regularly experiences widespread urban (non-riverine) flooding. The Village developed a Stormwater Management Plan from 2013-2015 to assess the significant flooding experienced in the western portion of the Village, analyzing several improvement options. Primary alternatives included several miles of large diameter storm sewer to increase conveyance capacity to the River, and three localized neighborhood underground stormwater storage basins, among others. After years of study, public participation, an independent value-engineering review and deliberation, the Village Board decided to move forward with the neighborhood storage option. The overall program was divided into 4 construction projects totaling nearly $64M. The project included a combined 40+ acre-ft of underground stormwater storage at three prominent parks with sports fields (one of them shared with two adjacent schools) within the Village and nearly five miles of large diameter storm sewers in dense residential neighborhoods with mature trees. In addition to the complex engineering, the project required significant coordination with residents, the park district, and the school district. The presentation will discuss the project, beginning in 2013, through completion of the final phase of construction in November 2022; including the public engagement, Park District Intergovernmental Agreement, scheduling, safety-sensitive construction and other unique features of what was the largest capital project in the Village's history.