The area of floodplains allowed to perform the natural function of storing and conveying floodwaters must be expanded by strategically removing levees or setting them back from the river. Floodplain reconnection will accomplish three primary objectives: flood-risk reduction, an increase in floodplain goods and services, and resiliency to potential climate change impacts [Opperman 2009: 1487].
Floodplain reconnection reduces flood risk by: (1) replacing vulnerable land uses with flood-tolerant uses, thereby reducing damages, and (2) giving the water somewhere to go, thereby sparing downstream and other nearby communities. Furthermore, by storing and conveying water, floodplains alleviate pressure on upstream dams/reservoirs for flood control and water supply, increasing the resilience of this infrastructure. Finally, by restoring biological activity and diversity, floodplain restoration activates ecosystem services, including carbon sequestration and water quality improvement and groundwater recharge.
The authors note that agricultural lands would be less expensive than densely populated residential areas to reconnect and should be prioritized. Furthermore, agricultural land could remain as such by switching to production of flood-tolerant crops, such as timber and pasture. Furthermore, floodplain reconnection has proven popular among farmers, who requested more than ten times the amount of land be enrolled in a one-time floodplain easement program than the USDA could afford to support with American Recovery and Reinvestment Act funds.
Opperman, Jeffrey J., Gerald E. Galloway, Joseph Fargione, et al., 2009, Sustainable floodplains through large-scale reconnection to rivers, Science 326, http://science.sciencemag.org/content/326/5959/1487.