Technical Abstract: The importance of floodplain backwaters within lowland riverine ecosystems is well established. However, these types of habitat are becoming increasingly rare as development is transforming floodplain landscapes in fundamental ways. Therefore, rehabilitation, protection, and management of riverine backwaters (floodplain aquatic habitats that are seasonally or periodically connnected to the main channel) are becoming increasingly common, with annual national expenditures now in the millions of dollars. Even with the increasing number of projects, general criteria for selecting restoration goals and evaluating project outcomes are lacking. To address this need, Kondolf et al. (2006) proposed an approach for evaluating river restorations is based on assigning a position to the system in a four-dimensional space that represents hydrologic temporal variability on one axis and connectivity in the three spatial dimensions on the remaining three axes. Use of the Kondolf approach for evaluating restoration of a backwater adjacent to a medium-sized river in northern Mississippi is presented as a case study, in which nearby degraded and less-impacted backwaters were used as references. The restoration project resulted in a reduction in main-channel connectivity and lower levels of variability for the treated backwater. Additional responses to treatment included increased summer water depth, moderation of severe diurnal water quality fluctations, and reductions in concentrations of solids, nutrients, and chlorophyll a. Fish species richness, numbers and biomass were unchanged following rehabilitation, but tropic structure shifted away from omnivorous species and toward predators. Ecological services provided by floodplain riverine backwaters may be enhanced by modest management measures, but regaining and maintaining connectivity with adjacent ecological functional patches remains difficult.