The U.S. Army Corps of Engineers (the Corps) has played a large and important role in shaping water resources systems in the United States since Congress first tasked it in 1824 to improve navigation on the Ohio and Mississippi Rivers. Since then, rivers have been modified for navigation and flood control, harbors have been dredged for shipping, and coastlines are routinely fortified against erosion and beach loss. Recent decades have seen an overall decline in budgets for civil works project construction, yet the range of objectives for water resources projects has broadened as society places more value on environmental and recreational benefits. Thus, the Corps' portfolio of water resources projects has changed considerably. There is a reduced emphasis on traditional construction projects and an increased focus on maintenance and reoperation of existing projects such as locks, dams, and levees and on environmental restoration projects. An integrated approach to water resources planning at the scale of river basins and coastal systems is widely endorsed by the academic and engineering communities. The Corps' mission, expertise, and experience give it immense potential to alter the structure and functioning of the nation's waterways and coasts. As might be expected in a large and complex organization answering to a range of public and private demands, implementation of these new policies and objectives is neither consistent nor complete. River Basins and Coastal Systems Planning within the U.S. Army Corps of Engineers recommends improvements in the Corps' water resource project planning and review process. This report compares economic and environmental benefits and costs over a range of time and space scales, suggests multiple purpose formulation and evaluation methods, and recommends integration of water development plans with other projects in the region.