Among some of the GAO's key findings are that:
- The Army Corps routinely assesses some of the hydrological impacts of the Middle Mississippi training structures that it constructs, but not of their environmental impacts (training structures being "dikes to 'train' the Mississippi River channel and maintain adequate depth for navigation").
- Researchers have routinely highlighted two key areas of concern with respect to those river training structures: degradation of river habitat and increased flooding.
- Regarding flooding, the Army Corps disagrees with researchers' concerns that its structures have led to an increase in Mississippi River stages during high flow events, and has undertaken various studies in efforts to support its supposition.
- Prepare an environmental assessment for river training structures in the Middle Mississippi River.
- Obtain required water quality permits for any new structures, and
- Conduct physical and numerical modeling to assess the cumulative impacts of those structures on River flood heights.