In 2004, an engineering study for the City of Champaign called for a $25.9 million overhaul of a central waterway and watershed called the Copper Slough.
The study by engineering firm Clark-Dietz said it found serious erosion, sewage and flooding issues and recommended various improvements along the slough.
Two decades later, repairs and stormwater management improvements on the Copper Slough are still a work in progress, as the city shifted priorities to address upstream neighborhood flooding.
The Copper Slough is a 6.8-mile-long watershed that stretches from Interstate 74 to the Kaskaskia River and has been surrounded by increasing residential development. In 2004, the Copper Slough Master Plan was created to address the issue and received the City of Champaign’s approval in 2007.
“The master plan is a general framework or guide, shifting priorities based on public input and City Council direction requires the master plan to be flexible enough to align with the stormwater needs of the City,” Alex Nagy, assistant city engineer for Champaign, said in an interview with CU-CitizenAccess.
The plan proposed a trunk sewer project to replace aging pipes and improve sewage flow. Nearly two decades later, Nagy said the plan needs an update.
“The estimated improvement amount is an old figure that needs to be updated at some point in conjunction with an update to the Copper Slough Master Plan,” Nagy said. “The master plan needs an update primarily due to outdated information, including completion of the West Washington and Garden Hills stormwater improvements. There are no current plans to update the master plan at this time.”
Targeted areas for construction in the plan included Hedge Road, Bradley Avenue, Washington Street, University Avenue, Maplewood Drive and Willowpark Drive, all of which are situated near the Copper Slough.
“The City has focused resources and budget on stormwater improvements in tributary sub-watersheds within the overall Copper Slough Watershed, primarily in the West Washington sub-watershed,” Nagy said.
A recommendation for a separate project for a $15 million transformation of West Washington Street was issued in 2007, including larger storm sewers, a local detention pond and improvements to the channels along the Copper Slough. Parts of that project addressed issues in the 2004 plan.
Since then, Nagy said $31 million has been funneled into West Washington Street over three phases, and as of June 2019, no further updates on the project have been set.
The Copper Slough plan details ten goals the city intends to address. The goals are as follows:
- Reduce potential flooding near channels of the Copper Slough
- Maintain hydraulic capacity at an adequate level
- Create maintenance standards for the sewer system and Copper Slough channels
- Protect the floodplain
- Create additional channels for restoration
- Separate the Copper Slough from Windsor Road
- Initiate water quality projects
- Integrate anti-dumping requirements into additional watershed projects
- Detach the Copper Slough from the Fountain Head Drainage District
- Build a hydrologic/hydraulic model for further analysis.
“After completion of the Copper Slough Master Plan in 2007, City Council ‘s stormwater priorities shifted from improvements directly along the Copper Slough channel corridor to upstream neighborhood flooding,” Nagy said. “West Washington and Garden Hills became the top priorities within the Copper Slough Watershed instead of the improvements identified in the 2007 master plan.”
Following these recommendations, engineering firm Clark-Dietz lists six broad proposed solutions in the original plan to address the ongoing issues in Copper Slough:
- Enlarge storm sewers
- Implement stream improvements
- Create ponds for flood detention
- Improve water quality
- Stabilize eroding streambanks
- Detach the Copper Slough from Fountain Head Drainage District
“Detachment from the Fountain Head Drainage District was finalized and became effective in February 2014,” Nagy said. “The City has also implemented small-scale channel repair and landscaping projects at locations where bank erosion has been a maintenance issue.”
Regarding the future of the master plan and its projects, Clark-Dietz sees it as a template rather than a checklist for outstanding issues, as stated in their final report.
“The Copper Slough Watershed Master Plan Report lists many solutions. However, these solutions will likely be implemented over a long period of time,” Clark-Dietz said in the report. “Many solutions may never be implemented, due to time and budget constraints.”