The GLMRIS Report presents the results of a multi-year study regarding the range of options and technologies available to prevent aquatic nuisance species (ANS) movement between the Great Lakes and Mississippi River basins through aquatic connections. Through a structured study process, USACE identified thirteen ANS of Concern established in one basin that posed a high or medium risk of adverse impacts by transfer and establishment in the opposite basin. USACE analyzed and evaluated available controls to address these ANS, and formulated alternatives specifically for the Chicago Area Waterway System (CAWS) with the goal of preventing ANS transfer between the two basins.

The report contains eight alternatives, each with concept-level design and cost information, and evaluates the potential of these alternatives to control the transfer of a variety of ANS. The options concentrate on the Chicago Area Waterway System (CAWS) and include a wide spectrum of alternatives ranging from the continuation of current activities to the complete separation of the Great Lakes and Mississippi River basins. The GLMRIS Report also includes an analysis of potential impacts to uses and users of the CAWS, and corresponding mitigation requirements for adverse impacts to functions such as flood-risk management, natural resources, water quality, and navigation.

The alternatives presented in the report include:

  1. Continuing current efforts (i.e., the electric barriers) with “No New Federal Action — Sustained Activities.”
  2. Nonstructural control technologies (i.e., education, monitoring, herbicides, ballast water management).
  3. A technology concept involving a specialized lock, lock channel, electric barriers and ANS treatment plants at two mid-system locations in the CAWS.
  4. A technology concept (CAWS buffer zone) using the same technologies as number 3, preventing downstream passage from Lake Michigan at five points and preventing upstream passage at a single point at Brandon Road Lock and Dam.
  5. Lakefront hydrologic separation with physical barriers separating the basins at four locations along the lakefront of Lake Michigan.
  6. Mid-system hydrologic separation with physical barriers separating the basins at two mid-system locations.
  7. A hybrid of technology and physical barriers at four mid-system locations, leaving the Cal-Sag channel open.
  8. A hybrid of technology and physical barriers at four mid-system locations, leaving the Chicago Sanitary and Ship Canal open.

The GLMRIS Report presents evaluation criteria to help readers distinguish among the alternatives. Evaluation criteria include design elements unique to each alternative such as initial or long-term operational costs and duration for implementation, as well as related qualitative features for each alternative, such as the magnitude of impact for existing waterway uses or relative effectiveness of preventing interbasin transfer.

Start with the Summary of the GLMRIS Report for an overview of these alternatives.


USACE accepted comments on the GLMRIS Report from January 6, 2014 through March 31, 2014 via public meetings, electronic submittal on the GLMRIS website, mail and hand-delivery. The public comment period is now closed.

Comments received during the public comment period are available on the GLMRIS Report Public Comments page. A summary of the public engagement activities conducted and the comments submitted during the public comment period are available in the Public Comment Summary Report.

Public Meetings

USACE hosted eleven public meetings following release of the GLMRIS Report. Videos, transcripts, slides and other materials from the public meetings are available at the GLMRIS Report Public Meetings page.