**The title, authors, and abstract for this completion report are provided below. For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**
Preliminary Feasibility of Ecological Separation of the Mississippi River and the Great Lakes to Prevent the Transfer of Aquatic Invasive Species.
Joel Brammeier2, Irwin Polls3, Scudder Mackey4
2 Alliance for the Great Lakes, 17 N. State Street, Chicago, IL 60602
3 Ecological Monitoring and Assessment, 3206 Mapleleaf Drive, Glenview, IL 60026
4 Habitat Solutions, 37045 N. Ganster Road, Beach Park, IL 60087
There is broad consensus that continuing introduction of new aquatic invasive species (AIS) into the Great Lakes is a major problem. Leading scientists suggest that future invasions put the Great Lakes at risk of “ecosystem breakdown” while prevention of new invasions is a top priority of the 2005 Great Lakes Regional Collaboration Strategy. Canals connecting the Great Lakes basin to other watersheds have served as an important pathway for these AIS introductions, second only to ballast water discharges from ocean going ships. The Chicago Waterway System (CWS) has already allowed several damaging AIS to move between the Great Lakes and the Mississippi River Basin, including the zebra mussel and round goby.
The imminent threat of Asian carp reaching the Great Lakes and knowledge of the impacts of past invasions creates a strong incentive to permanently protect both the Great Lakes and Mississippi Basins from new invasive species. State and federal governments have invested wisely for the short term by developing electric barriers that are effective against current invaders. But even if the barriers operate as designed, they will not last forever, nor will they ever achieve guaranteed 100 percent effectiveness. With the passage of time – through human error, an accident, or a natural disaster – the effectiveness of the barriers will be compromised.
The long-term approach to achieving protection is “ecological separation.” A true ecological separation is defined as no inter-basin transfer of aquatic organisms via the Chicago Waterway System at any time – 100% effectiveness. Ecological separation prohibits the movement or interbasin transfer of aquatic organisms between the Mississippi and Great Lakes basins via the CWS. Once established, the impacts of invasive species on ecosystem health are permanent and irreversible. Preventing the transfer and introduction of invasive species between the Mississippi River and Great Lakes basins is the only long-term solution that will eliminate the risk of irreversible ecosystem damage.
The CWS is a highly engineered and complex combination of natural rivers and artificial canals. Much of the system has been channelized to facilitate its primary purpose as a treated wastewater and stormwater conduit downstream from the city of Chicago. As a result of this and other human activity, ecological values of the CWS such as habitat quality have been compromised. However, the system functions as a thriving recreational network and maintains steady, if not growing, traffic in commodity movements. Until recently, many users and stakeholders have assumed that the availability of regular connectivity and an accompanying threat of AIS movement between the CWS and Lake Michigan was a foregone conclusion given twin demands for wastewater management and navigation. A close look at system flows, navigation patterns and short- and medium-term regulatory imperatives suggests otherwise. The need for direct diversions of Lake Michigan water into the CWS is diminishing and navigation is confined in bulk to specific portions of the system.
Stakeholders, with a few exceptions, are hospitable to the idea of ecological separation. Most stakeholders have a firm understanding of the benefits provided to the city of Chicago and state of Illinois by the CWS and understand the tremendous quality of life enhancements offered by the system as it currently exists. Despite this, some view the permanent connection of the Mississippi River and Great Lakes as a mistake with unforeseeable consequences that needs to be rectified. Fortunately, existing planning and modeling resources will shorten the timeframe for and reduce the cost of analysis that needs to occur prior to project implementation.
Strategies for separation can be pursued at Lockport/Romeoville, the south branch of the Chicago River, the Chicago Lock to Lake Michigan, and the Calumet, Grand Calumet and Little Calumet Rivers. Ecological separation at several of these points will require new infrastructure that is almost certain to impact commercial and recreational navigation. Traffic flows in the CWS suggest that these impacts can be minimized; the flow of goods, vessels and passengers could even be enhanced if ecological separation was addressed as part of a revitalized Chicago-area navigation infrastructure. Impacts to movement of stormwater and wastewater are highly dependent on whether separation is located in the upper or lower part of the system, with impacts growing extreme if any separation occurs lower in the CWS.
Achievement of ecological separation can be hastened by:
Ř Prioritization of an outcome of ecological separation by a federal authority such as Congress or an administration via an executive order;
Ř Clarifying and authorizing project implementation responsibility;
Ř Completing detailed studies on changes to hydrology, recreation and commodity logistics that would result from any infrastructure alterations; and
Ř Establishing a stable, multi-year source of funding for federal studies and project implementation.
Short of immediate ecological separation, protection from species movement can be partially achieved by:
Ř Completing and activating the electrical barrier system in the Chicago Sanitary and Ship Canal.
Ř Hydrologically separating Indiana Harbor and Burns Ditch from the Grand Calumet and Little Calumet Rivers, respectively, to eliminate opportunity for species movement.
Ř Acquiring state and federal administrative approvals for a rapid response plan for the CWS and educate local stakeholders on the potential impacts of rapid response activities.
Ř Immediately beginning a federal feasibility study on separation of the two systems under existing federal authority via the Corps.
While the U.S. Army Corp of Engineers is viewed as the natural lead on a separation project, an apparent leadership vacuum makes envisioning ecological separation difficult. Engineering and siting concerns should not be limiting factors in ecological separation, but a commitment to act from high level decision makers combined with a stable federal funding source are both required.
Invasive species prevention is the rare ecological problem where opportunity and consensus tend to arrive in tandem. Presented in the CWS is the opportunity to prevent damage to two great watersheds combined with consensus that some drastic action is likely necessary to achieve that prevention. Lack of information is no hurdle to meeting this challenge, but successful prevention will demand leadership and will to get the job done. We encourage the Great Lakes and Mississippi River regions to act on this opportunity as quickly as possible.