Uncertainty and Legal Foreseeability in Flood Risk Management

Abstract

The legal concept of foreseeability is an important element of proof in flood loss litigation against the US Army Corps of Engineers. Although hydrologic forecasting and engineering uncertainty address foreseeability, the civil engineering literature lacks discussion of how flood risk managers should consider the legal concept during the life cycle of projects. The 1928 Flood Control Act holds federal agencies immune from liability due to flood projects, so the litigation takes the alternate approach of takings per the Fifth Amendment of the US Constitution. Although foreseeability is a long-standing legal concept in determination of personal injury causation, flood risk scenarios involve many more players and complexities. If judges use concepts from simpler situations to judge complex flood cases, it might bias outcomes. A conceptual example synthesizes the main actions in five riverine flood cases against the Corps of Engineers that were alleged to be the proximate causes of flood damages. Foreseeability issues are discussed for hydrologic uncertainty, channel capacity, the condition of reservoirs and levees, changed project purposes, and land development. Based on these, current practices of the Corps of Engineers to address uncertainty and foreseeability in flood projects are reviewed.