A river runs through it once again.
Spring Brook Creek, located within the St. James Farm and Blackwell Forest Preserves of the DuPage River watershed, has been revitalized following a partnership of WBK Engineering, Forest Preserve District of DuPage County (FPDDC) and The Wetland Initiative (TWI).
Decades of rapid population growth for the Chicago region, beginning as far back as 1850, precipitated the need for accompanying land development for commercial, industrial, and residential use. Land was altered to fit new demands, with some lasting environmental impacts that needed attention.
This attention came in the way of a team of preservation and engineering experts converging on Spring Brook Creek, which had become a stagnant, channelized ditch to assist in irrigation and development of surrounding farmland. The team’s goal was to re-naturalize over two miles of creek, returning the environment to its days as a lively ecosystem for a variety of plants and animals.
The first step in restoration was taking the stagnant ditch and re-meandering it back into its predevelopment condition as a winding, moving stream. The stream re-meander was hydraulically modeled using one-dimensional steady-state models to check the effectiveness of the geomorphological enhancements by assessing bank-full flow conditions, flood inundation areas, and flow velocities. In areas with complex flow regimes, where the flow could not be adequately captured by one-dimensional models, WBK utilized two-dimensional models to determine flow direction and distribution. Hydraulic models were also used for assessing hydraulic adequacy of bridges, evaluating impacts of dam removal, and ensuring regulatory floodway construction rules were met.
Through this re-meandering work, the Creek channel length expanded from 2,000 feet to 3,200, with deep bends accentuating the turns. WBK engineers and ecologists, including Civil Engineering Practice Lead John Witte, were able to include a variety of natural features such as “riffles,” adding rocks and other natural elements at strategic spots in the stream to rouse the water, encouraging healthy oxygenation and the removal of excess water-borne nutrients. “This also facilitates micro-organism abundance within the water,” Witte explains, “creating more food sources for the many varieties of fish in the streams.”
WBK staff then worked to bring back native plant-life, including blue flag iris and rose mallow, replacing the grasses that did little to offer nutrition for the surrounding wildlife. With clean water and new food sources, animals began to return to their former homes.
Perhaps most importantly, the work by WBK Engineering and partners reconnected the stream to the greater floodplain, allowing for a more fully developed ecosystem to thrive. The waterway became a fish passage once again, thanks to the removal of a small dam and the regrading of a very steep segment of stream.
The Forest Preserve District of DuPage County has been an integral partner in this revitalization effort. Their mission is “to acquire and hold lands containing forests, prairies, wetlands and associated plant communities or lands capable of being restored to such natural conditions for the purpose of protecting and preserving the flora, fauna and scenic beauty for the education, pleasure and recreation of its citizens.”
Scott Meister, Manager of Natural Resources with the FPDDC, has been very pleased with the results of the Spring Brook project. “The restoration of Spring Brook has been incredibly successful and could not have been possible without the assistance of multiple partners, including WBK Engineering. The Forest Preserve District of DuPage County has been working with WBK on multiple phases of this restoration project since 2014, and we continue to partner on a third and final phase. The impact of this project will have long-lasting positive effects on our community, including cleaner water, reduced flooding, and improved wildlife habitat. From design to permitting to construction, WBK has been an integral part of project’s success, and we look forward our continued partnership to advance the mission of the Forest Preserve District.”
This revitalization of the area is of great benefit to plants and animals alike, and it also transformed it into a nature getaway for people to experience the beauty of the area once again. The re-meandering and addition of the riffles brought back the sound of moving water. Greg Chismark, President of WBK Engineering, explains the benefit, “Moving water is healthier water and creates a calming backdrop for DuPage Forest Preserve District patrons taking advantage of the redesigned trails and bridges which were also part of the project.” With a vibrant, clean stream, the sounds of bird songs soon returned, as the surrounding environment is slowly responding to the area’s re-naturalization.
The project also included a new way to appreciate the revitalized space with WBK’s design of a multi-use path and two bridge structures. The realignment of the stream impacted an existing equine trail and provided an opportunity for the FPDDC to introduce trail modifications that followed the site master plan. WBK structural engineers designed two bridges, an access road slab bridge to replace the existing deteriorating structure and a new single-span refabricated pedestrian truss bridge over the realigned channel. The new bridge served as a connection between the old and new trail systems within St. James Farm.
Living in an urban center like Chicago and its busy suburbs, it’s difficult to get a full appreciation for the calm and beauty of the world. Less than an hour outside the city, away from the trains and traffic, lies a nature reserve getaway for fresh air and exploration. With a revitalized ecosystem made possible through the strong and ongoing partnership between WBK Engineering and the Forest Preserve District of DuPage County, Spring Brook Creek has been returned to nature.