(Above) Flooding along the new Chicago Riverwalk between State Street and Dearborn Street on Friday morning. Photo by Lynn Becker. Click on images to view larger versions.

August 23, 2014 – The State Street Bridge will stay up two more days. The level of the Chicago River, raised by heavy rain on Thursday and Friday, was too high for workers on the Chicago Riverwalk to complete installation of a caisson under the bridge. Chicago Department of Transportation now says the bridge will open on Monday at 6 a.m.

CDOT is not expecting the river level to drop sufficiently until Saturday morning.

More than four inches of rain fell at Midway Airport on Friday. The Riverwalk was “partially flooded,” according to CDOT, although most of it appeared to be under water.

The caissons are long steel tubes filled with concrete and rebar that will anchor the Riverwalk to the ground deep below the river. Three caissons are being installed beneath the south leaf of the State Street Bridge. A caisson on the east side of the bridge will be installed during the week of August 25.

(Above) At far right, a crane lowers into a caisson a green rebar cage made of steel that will help solidify the concrete poured into it. The tugboat Tanner is on hand at left to reposition the construction barge. (Photo by Steven Dahlman.)

CDOT also announced it is expecting delivery that week of the pre-fabricated walkway that will go under the Dearborn Street Bridge.

The Riverwalk will soon sprout details such as walls and planters. Forms will be installed to hold concrete for these parts, along with footings to anchor stairs to the Riverwalk.

• Previous story: State Street Bridge to close again for Riverwalk work
• More photos: Riverwalk construction