We examine the efficiency of current flood risk allocation and the use of flood easements as a means of reallocating flood risk and reducing total flood damages in large river floodplains. Changes in agricultural floodplain land use and levels of crop insurance coverage as the risk of flooding changes are simulated using mathematical programming. The net benefits of flood easements to a portion of the Lagrange Reach of the Illinois River region are then simulated. Our results indicate that flood easements may provide positive net benefits. This positive result stems primarily from the decreased risk of flooding for non-inundated agricultural levee districts, rather than from reduced municipal flood damages. Our results are robust to changes in the estimated dollar damages, yet extremely sensitive to changes in hydrological estimates.