Bridge improvements coming to Hidden Lake Forest Preserve

DuPage Forest Preserve District officials are moving forward with plans to replace one bridge and rebuild another at Hidden Lake Forest Preserve in Downers Grove.

The Forest Preserve District Board of Commissioners has unanimously approved a contract for phase 2 engineering services for the design and regulatory permitting necessary to rebuild a historic bridge over the East Branch DuPage River that connects the north half of the preserve to Eagle Lake on the south end. Construction is expected to begin in early summer 2021 and be completed by the end of the year.

The consultant determined the 50-foot-long by 11-foot-wide wrought iron bowstring pony truss bridge was only built in the 1870s by the King Iron Bridge Company in Cleveland, Ohio, according to Brock Lovelace, district manager of Engineering and Environmental Services.

Looking at old plat maps from that time period, "they also determined that this bridge very likely sits in the exact same location in which it was installed in the 1870s," he said.

"We're going to try to bring it back as close as we can to the original condition," which will cost $20,000 to $30,000 more than replacing the bridge. A replacement is expected to last only about 40 years, whereas the rebuilt bridge is expected to last another 100 years, Lovelace said.

"In terms of the long-term costs of this bridge, it makes more financial sense to rebuild it," he said. "We end up making a return on our investment pretty quickly."

The other bridge - at Round Meadow Lake to the north - is an 80-foot-long by 6-foot-wide prefabricated bridge that carries a pedestrian trail over the outlet for Round Meadow Lake. The bridge is 38 years old; it was donated to the district by the Village of Addison in 2006 and installed at Hidden Lake in 2008.

It will be replaced with a standard 14-foot-wide steel truss prefabricated bridge similar to ones installed recently at Mallard Lake, St. James Farm and Blackwell forest preserves.

During construction, the Eagle Lake portion of the preserve will be closed and there will be periodic disruptions to the loop trail around Round Meadow Lake.

Both bridges are certified projects on the district's master plan. The project is expected to cost $800,000 and will be funded out of the district's construction and development fund.

For information, call (630) 933-7200 or visit dupageforest.org, where you can also link to the district's e-newsletter, blog, Facebook, Twitter and Instagram pages.