McDowell Grove Entrance Road Bridge Replacement and Trail Improvements
In 2016, the District will begin engineering design for the replacement of the existing vehicular entrance road bridge and construction of a new 0.25-mile long multi-use trail at McDowell Grove Forest Preserve
The existing entrance into McDowell Grove Forest Preserve resides on the east side of Raymond Drive, approximately 0.35-miles south of Diehl Road, in unincorporated Naperville. The two-lane entrance road from Raymond Drive connects to a one-lane vehicular bridge over the West Branch of the DuPage River which brings preserve users to an existing parking on the east side of the river. The bridge was originally constructed in the 1940s, with superstructure improvements made over the years.
There are several issues with the existing bridge and entrance road:
1. The two-lane entrance road approaches the one-lane bridge on a sharp curve on a steep down gradient creating safety concerns during wet or icy conditions.
2. The bridge serves as both the primary pedestrian and vehicular access across the river and is considered part of the heavily utilized West Branch Regional Trail. Due to the limited width of the bridge, pedestrian safety is a concern due to the potential for vehicular/pedestrian conflicts.
3. The bridge is constructed on driven piles within the river which typically catch debris during flood events. Coupled with the fact that the bridge deck elevation is lower than the base flood elevation, the ability for the aging bridge to withstand the structural stresses imposed by flood conditions in the future has become a concern.
4. The bridge is restricted to a 5-ton weight limit.
In 2006, the District’s Board of Commissioners approved a preliminary engineering contract with Strand Associates in order to determine potential alternatives for replacement of the bridge. Due to financial constraints at that time, the Board chose to move forward with design engineering for only replacing the deck of the existing bridge, and constructing a new pedestrian bridge to the north along with associated trail improvements. The project was placed on hold shortly thereafter due to anticipated river restoration and dam removal work within the preserve. The river work was officially completed in 2014.
In 2014, an inspection of the bridge found conditions that warranted downgrading the weight limit of the bridge to 5-tons. This weight restriction has significantly impacted access to the preserve for emergency vehicles and District operations. In 2015, the District Board of Commissioners directed staff to move forward with selecting an engineering consultant to design a new bridge that will carry two lanes of traffic and a multi-use trail. The bridge will be designed to provide a clear span over the river, and correct the alignment of the road as it approaches the bridge from Raymond Drive. For a conceptual view of the proposed improvements, click here.
Construction plans and specifications were released for public bid on March 29, 2017 and the bidding period will be closed on April 21. It is anticipated that a contract for construction of the project will be executed on May 16, 2017 with construction starting shortly after.
Due to safety concerns, the work zone will be off-limits to the public from approximately June through November. The impacted areas include the entrance road, parking lot, and the portion of the West Branch DuPage River Trail as shown in red on the closure map. In the meantime, the District has partnered with Naperville to route a 6.8-mile detour for trail users who would normally pass through the forest preserve on their way along the 23-mile regional trail. For more information, please see the detour map.
On April 4, 2017, the Board of Commissioners approved utilizing residual funds from completed projects in addition to previously allocated Bond funds for the estimated $2,388,000 project.