CBBEL was part of the Stantec team selected by IDOT to complete Phase I Engineering and Environmental Studies for proposed added lanes on I-55. CBBEL’s Drainage Engineering services included completion of two Hydraulic Reports for the rehabilitation of Pump Station 30 to provide support for the selected improvement project under varying lane configurations. CBBEL analyzed multiple stormwater conveyance, storage and pump station upgrade alternatives for hydraulic operation, cost and constructability to meet IDOT design requirements, including under Bulletin 75 rainfall events. In addition, CBBEL prepared waterway Hydraulic Reports for five floodplain/floodway crossings, including Flagg Creek, the Des Plaines River and the Chicago Sanitary and Ship Canal.