Protecting undeveloped land within floodplains significantly reduces property damage caused by flooding events, as shown by an eleven-year nationwide study of 450 communities. Communities protecting open space under FEMA’s Community Rating System saved, on average, $200,000 per year in property damage caused by floods.
Brody, Samuel D., and Wesley E. Highfield. (2013). Open space protection and flood mitigation: A national study. Land Use Policy, 32, 89-95.