When the Mississippi River rose to near record levels in 2011, the U.S. Army Corps of Engineers (Corps) intentionally broke several levees along the river, thereby flooding normally protected areas in order to prevent greater damage elsewhere. The decision to detonate levees has been controversial, with opponents arguing that levee detonation combined with the resulting flooding may render extensive amounts of farmland unproductive for a generation. The 2011 Mississippi River floods brought renewed attention to federal liability for floods, which has been the subject of ongoing litigation since Hurricane Katrina. Hurricane Katrina struck the Gulf Coast in August 2005, bringing with it rain, high-velocity winds, and a large storm surge, and leaving behind a massive path of destruction. Much of the extensive damage that occurred resulted when the storm surge breached levees and floodwalls protecting New Orleans. Some of these structures were part of the federally authorized Lake Pontchartrain and Vicinity Project (LPV), constructed by the Corps and maintained by local levee districts. By August 31, 2005, 80% of New Orleans was under water. While some flooding was expected in New Orleans, primarily because the city sits below sea level and lacks natural drainage, the extent of inundation was unprecedented. In many instances, like that of Katrina, floods occur when natural conditions prove too extreme for flood control structures or those structures fail. In other instances, like that of the 2011 Mississippi River flooding, the Corps may flood certain lands in order to reduce damage to other areas. This report examines the legal issues resulting from flood damage in both instances. It analyzes the general framework of liability claims for flood damage and federal government immunity under the Federal Tort Claims Act (FTCA) and the Flood Control Act of 1928 (FCA). The report specifically analyzes claims for federal liability for damage caused by Katrina. Finally, it examines the legal issues surrounding the Corps' decision to activate floodways along the Mississippi River in 2011. As a threshold issue, any suit against the federal government (including the Corps) must overcome the doctrine of sovereign immunity. Sovereign immunity means that the government cannot be sued. Congress, however, may waive sovereign immunity and allow the federal government to be sued in specific circumstances. The plaintiff bears the burden of proving that it has the right to sue the government. The FTCA and the FCA govern when lawsuits may be filed against the federal government for flood damages. The FTCA and the FCA frequently appear as defenses to the same claim. One federal circuit court has held that the FTCA does not overrule or invalidate the immunity provision of the FCA. Courts generally consider the underlying liability claim only after determining that the immunity provisions do not apply. The FTCA waives the federal government's sovereign immunity if a harmful act of a federal employee causes damage. Specifically, the FTCA creates liability for the following: injury or loss of property, or personal injury or death caused by the negligent or wrongful act or omission of any employee of the government while acting within the scope of his office or employment, under circumstances where the United States, if a private person would be liable to the claimant in accordance with the law of the place where the act of omission occurred. The FTCA contains a number of exceptions under which the United States may not be held liable even if negligent. Among these, the discretionary function exception prevents the government from being sued for any claim ... based upon the exercise or performance or the failure to exercise or perform a discretionary function or duty on the part of a federal agency or an employee of the government, whether or not the discretion involved be abused. The Supreme Court has provided clarification on the discretionary function exception of the FTCA. In Dalehite v. United States , the Court described discretion as being "more than the initiation of programs and activities. It also includes determinations made by executives or administrators in establishing plans, specifications or schedules of operations. Where there is room for policy judgment and decision there is discretion." In United States v. Varig , the Supreme Court found that an agency's execution of a decided-upon action is also a discretionary action. In United States v. Gaubert , the Court stated a two-part test for applying the discretionary function exception. Under the test, (1) the challenged conduct must involve an element of judgment or choice, and (2) the judgment or choice must be based on considerations of public policy. Claims arising from the performance (or non-performance) of mandatory functions required by statute are actionable under the FTCA. Thus, if the government fails to comply with an action required by Congress, the government is not protected from liability. If an action includes both mandatory and discretionary elements, the court must determine which part of the government action Congress specifically required, and which part involved discretion. For example, although Congress specifically required construction of the New Orleans Hurricane Protection System, how it was constructed was discretionary. Courts typically interpret the discretionary function exception broadly. Generally, the discretionary function exception has prevented claims against the United States for water damage to real property resulting from negligent design or construction of flood control or irrigation projects. In Vaizburd v. United States , plaintiffs alleged that a Corps project to reduce storm damage and protect the shoreline damaged their property because of negligent design and implementation. The court used the Gaubert two-part test to find that the Corps exercised discretion in the design, planning, and implementation of the project. The court found that the Corps chose from several different project plan designs in light of a number of policy considerations, including cost, reliability, resource allocation, environmental protection, and political implications. The court also found that even though the project was required by statute, the actual implementation of the project was not dictated by any plan, regulation, or statute, and thus, the Corps had discretion in how to implement the project. Accordingly, even if there has been negligent design or implementation, the presence of choice and judgment may allow the discretionary function exception to preclude any claim against the United States. A discretionary function can exist in the choice of materials for a required project. In United States v. Ure , the plaintiff argued that the government was negligent in constructing an irrigation canal that burst and flooded the plaintiff's property. The plaintiff claimed the government's duty to ensure against breaks was breached because the canal had not been constructed with a stronger (and more expensive) material. Ultimately, the court found that the government's cost-based decision not to use stronger material was subject to the discretionary function exception. Similarly, when the government builds infrastructure to withstand a certain level of storm, although recognizing that more powerful storms are possible, courts have held that the discretionary function exception applies. In Valley Cattle Co. v. United States , the plaintiff contended that the government was negligent and liable for damages because its flood preparations could handle only a "two-year storm" despite knowledge that much stronger storms hit the area. The court found that the government made decisions at the planning level to prepare only for a two-year storm based on policy factors, and was immune from liability because of the discretionary function exception. Even deciding to delay project improvements can excuse liability under the discretionary function exception. In National Union Fire Insurance v. United States , the court held the Corps' decision to delay a small improvement to a breakwater while planning for a larger improvement was a choice immune from liability. Despite the Corps' awareness of problems with the breakwater protection prior to the plaintiff's property being damaged, the court held that the FTCA's discretionary function exception applied because the Corps had made a decision regarding timing of the improvements. The court also found that considering the cost of greater safety is a discretionary function. Under some circumstances, maintenance has been found not to be a discretionary action. In E. Ritter & Co. v. U.S. Army Corps of Engineers , the court found the government liable for failing to maintain a flood control project. Although the Corps had decided not to maintain the banks of the project, the court found that the discretionary function exception did not automatically apply whenever a decision was involved. Relying on the second prong of the Gaubert test, the court found that only government decisions based on considerations of public policy are protected by the exception. The court found the discretionary function exception did not apply because operating the project incorrectly was not part of the Corps' mandated policy to prevent flooding. In more recent cases, courts have found that the level of maintenance of a government project involved considerations of public policy. In a case based on the National Park Service's (NPS's) failure to maintain a road, the court looked at whether a decision had been made regarding maintenance. It considered that the NPS had developed a maintenance task list, and that maintaining that particular road was to occur following other projects. According to the court, scheduling was discretionary, since agencies are allowed to establish priorities "by balancing the objectives sought to be obtained against such practical considerations as staffing and funding." In a similar case, NPS trail maintenance was held to be a discretionary action. In that case, the court reviewed the policy-prong of the Gaubert test to find that agencies are allowed to balance public policy against "the constraints of resources available to them." Even if litigants are able to refute the discretionary function exception and sue the government under the FTCA, the FCA offers additional immunity to the federal government. Section 702c of the FCA provides that "no liability of any kind shall attach to or rest upon the United States from any damage from or by floods or flood waters." Section 702c immunity is not available exclusively to the Corps, but rather may also be available to the Bureau of Reclamation within the Department of the Interior. The overall breadth and scope of FCA immunity from liability is the subject of considerable controversy and litigation. Despite the Supreme Court's comment that "it is difficult to imagine broader language," the case history of the FCA evidences a more nuanced application.