Large river systems are valuable national resources that provide numerous benefits to travel, shipping, recreation, and fish and wildlife. However, efforts to expand one of the uses frequently come in direct conflict with one or more of the othersThis guide attempts to bring together all scientific data that are available on techniques that have been or can be used to offset or reduce the impacts of development and maintenance of Upper Mississippi River System or other large river systems. Decision makers are thus provided an objective descriptin of options now at their disposal when they attempt to weigh the merits of defects associated with a particular action.