Across the lake the threat of Asian Carp is lurking. The Chicago Area Waterway System (CAWS) has a dangerous connection to both the Great Lakes and the Mississippi River. It allows aquatic invasive species (AIS) from the Mississippi, such as the Asian Carp, to make it’s way to the Great Lakes. These fish could out-compete native fish, and consume large amounts of the plankton that is essential for a healthy aquatic ecosystem. North America is void of any fish large enough to eat adult Asian carp.
The preferred science-based, ecologically friendly solution is separation of the Mississippi and the Great Lakes via the CAWS. “Control efforts being coordinated by federal and state agencies are providing critical protection to hold back the advance of Asian carp toward Lake Michigan. These efforts are vital and are buying us time to develop and implement separation in the CAWS. Recent research is confirming that The Great Lakes do provide a hospitable environment for Asian carp, particularly shallow near-shore areas such as Green Bay, Saginaw Bay, Lake St. Clair and the western Lake Erie basin,” said Christine Manninen, Communications Director for the Great Lakes Commission.
A new report highlights three separation models proposed by the Great Lakes Commission and the Great Lakes and St. Lawrence Cities Initiative. The goals for a successful separation include, preventing the passage of AIS, improving water quality and protecting against flooding through the CAWS, while supporting and improving the existing regional transportation infrastructure.
A successful separation plan will require modifications and improvements in the CAWS to prevent excessive flooding. The Tunnel and Reservoir Plan (TARP), scheduled for completion in 2029, aims to prevent excess flooding by improving passage of stormwater and wastewater into an expanded floodplain storage area. Until the TARP is finished a one-way barrier would prevent most flooding with occasional overspill into Lake Michigan. Green infrastructure will also be imposed on Chicago’s current sewer, road and water construction programs. “Green infrastructure investments would include green technologies such as rain gardens, bioswales and pervious pavements,” said Manninen. Increased stormwater retention for private construction would also be demanded to control flooding as well.
Currently Chicago’s wastewater is dumped into the Des Plaines River, which then streams to the Mississippi River. Separation would inevitably require Chicago’s treated wastewater to be dumped into Lake Michigan instead of the Mississippi. The water quality standards for Lake Michigan are more stringent than those of the Mississippi so separation would increase water quality for the Mississippi and the Great Lakes. Flow augmentation will also be facilitated to prevent stagnant water on both sides of the barriers.
The separation options are very promising but time is ticking and the vicious Asian carp along with other species foreign to the lakes are getting closer with every passing day. Currently, there is an electric barrier to keep the carp at bay but carp DNA has shown up across the barrier confirming that the barrier is a band-aide fix for an open wound. The complete separation could take decades to be completed and at this rate the lakes just don’t have that kind of time.
In order to move forward congress should encourage the Army Corps of Engineers to provide an action plan more swiftly, which has been estimated to take 3 years. The “Stop the Asian Carp Act” would require the Army Corps to have an outline in 18 months.