The pump station project consists of several parts, including an underground water storage vault on Forest Avenue, an above ground storage facility on Forest Avenue and a new storm sewer on Washington Avenue. | Illustration by Javier Govea

Work on a pump station and both above- and below-ground storm water detention facilities should begin in early- to mid-August in the vicinity of Washington and Forest avenues in Brookfield, the village’s engineer confirmed earlier this week.

The long-anticipated flood-mitigation project got the final go ahead on April 21, when the board of the Metropolitan Water Reclamation District of Greater Chicago voted unanimously to approve an intergovernmental agreement with the village of Brookfield to share the roughly $2.1 million cost of construction.

According to Village Engineer Derek Treichel, the village plans to award a contract for the work on June 13. But because there is lead time needed to obtain equipment for the pump station’s motor control center, the generator and the pumps themselves, construction won’t start until later this summer.

Treichel said construction on the pump station and storm water detention areas would last until about mid-November.

The MWRD has agreed to pay up to $1 million to build the facility, which was proposed to address flooding that affects Forest Avenue and the area near the intersection of Washington and Prairie avenues.

When complete, the flood-control system will include an underground pump station north of Washington Avenue just west of Salt Creek. The pump station will be topped by a generator and will be outfitted with five pumps capable of ejecting 5,000 gallons of water per minute from the storm sewers into Salt Creek during heavy rain events where the creek does not overtop the banks of the river.

An underground storm water vault measuring 7-by-8-by-300 feet and capable of storing 120,000 gallons of water will be located underneath the street in the 3500 block of Forest Avenue.

That vault will be connected to a 65-by-105-foot, above-ground storm water detention facility at 3526 Forest Ave. that is capable of holding up to 150,000 gallons. The property will be fenced in by decorative wrought-iron. The holding area itself, which slopes to a depth of 8 feet, will be covered with grass and maintained by the village.

Finally, a new 36-inch storm sewer will be installed on Washington Avenue from Prairie Avenue to Salt Creek. A section of combined sewer on Forest Avenue will also need to be moved to the west as part of the project.

Construction of the underground vault on Forest Avenue will close that roadway to traffic while it’s being built. Traffic on Washington Avenue may also be interrupted for certain periods to allow machinery needed for the construction of the pump station, including cranes, to operate, Treichel said.

According to Treichel, the first work to be done will be moving the combined sewer on Forest Avenue. That will be followed by construction on the pump station structure north of Washington Avenue, then the storm water detention areas.

Installation of the new sewer on Washington Avenue will take place later in the project, Treichel said.