In September 2000, the Corps reported that completion of its feasibility study would be delayed. As the committee was contractually obligated to finish its study in February 2001, it was clear that a final Corps study would not be available for the committee's review. Nonetheless, the National Academies and DOD agreed that an interim report would be useful. The committee's report thus focuses on a July 2000 draft of the feasibility study, on a draft environmental impact statement, and on numerous studies and reports that the Corps presented to the committee as key supporting documentation in the draft report.
The committee is mindful of its original assignment to examine the Corps' final report. As the Corps has yet to finish its feasibility study, the assessment and recommendations in Chapter 4 do not critique the Corps' final report, but rather comment upon a draft of the final report and relevant supporting documents provided by the Corps. Because the Corps decided that more analysis was required before it could produce a final feasibility report, the Corps may have already changed some of the plans the committee describes and analyzes in Chapter 4 . The committee thus presents its report with the hope that it will prove useful to the Corps as it continues the analysis and preparation of the final feasibility report.
The prospective lock extensions on the lower UMR–IWW are highly controversial, as was made clear by the high level of participation and passion displayed by proponents and opponents during the committee's meetings and public comment sessions in Washington, D.C. and St. Louis in June and August 2000, respectively. It is not easy to pursue this difficult analysis of the UMR–IWW in such a highly charged atmosphere.
The Corps attempted to build the first comprehensive model of grain use and exports from the area surrounding the river system, and attempted to build a model of the environmental effects of extending the locks and increasing barge traffic. These two studies are exceedingly difficult, and the committee commends the Corps for undertaking them and making important advances. The committee also offers recommendations on how the final feasibility study could be improved over the draft reviewed in this report.
The committee's recommendations for improving navigation system planning on the Upper Mississippi and Illinois system are divided into four areas: economics, inland waterway and water resources system planning, the environment, and engineering. The Corps itself may not be able to unilaterally implement all of the committee's recommendations. The Corps operates at the behest of the U.S. Congress, and the committee recognizes the roles of Congress in granting enabling authorities and appropriations for Corps water resources studies and projects. In addition, the federal Office of Management and Budget (OMB) establishes fiscal priorities for water resources projects. The Corps' discretion to carry out certain studies and projects is thus not always matched by the funds to do so.
The Corps is, however, granted a certain degree of latitude in various authorizations and in its feasibility studies. The committee thus primarily directs recommendations that can be implemented within the Corps' discretion to the Corps of Engineers. Recommendations beyond the Corps' discretion to enact are directed to the U.S. Congress.
Some of the committee's recommendations will require sustained and significant resources in order to be implemented, requiring Congressional appropriations. The Department of Defense's request for a rapid evaluation of the draft study meant that some potentially useful aspects of the committee 's review could not be accomplished in such a short time frame. The agreed that the committee should not be asked to estimate the resources required to implement the