Despite many decades of efforts directed to reduce floods risks across the US, mainly in river floodplains and along coastal areas, many citizens and structures remain at risk of being flooded. Occupation of low-lying areas is itself not necessarily problematic. However, the risks of flooding are not always widely appreciated by inhabitants at risk, and appropriate planning and preparedness options – such as purchase of flood insurance policies, and the use of building-specific flood proofing materials and actions – are not always widely adopted and practiced. The US Army Corps of Engineers (USACE) has major authority and responsibility for federal flood risk management personnel and actions. In an earlier era, many of these actions took the form of “structural” flood protection actions, primarily dams and levees. There are some limits to these measures, however; for example, levees may be overtopped, or they may fail. Further, it has been noted that despite the construction of numerous flood protection structures across the US, this has not necessarily reduced lives lost or property damaged during floods. There are thus are many reasons why structural measures should be complemented by “non-structural” measures. In addition to measures mentioned above, these may include flood warning systems, zoning measures designed to limit the number of buildings located in floodplains, and physical relocation of some structures to higher ground. Although many such measures are beyond the authority of the USACE, the agency has fundamental dam operations and levee inspection and maintenance responsibilities and is a leader in US flood risk management. The USACE strives to coordinate and integrate input and resources from other relevant federal agencies, such as the Federal Emergency Management Agency (FEMA), states, communities, the private sector, and nongovernmental life cycles (NGOs) in promoting a comprehensive approach to flood risk management. In addition to identifying and implementing programmes and actions encouraging wiser use of floodplain areas, there also is need for more harmonious co-existence with occasional, but inevitable and useful, floods. This will entail mitigation and preparedness measures that are less expensive and more efficient and nimble, and that allow communities to rebound quickly in the wake of a flood.
To seek processes, programmes and initiatives that build on traditional and existing structural flood control elements, which acknowledge current budget realities, and that seek wise use of limited resources and intelligent uses of flood hazard areas. There is no “quick fix” for the challenges at hand. Wiser uses of those areas in the US subject to flood waters and coastal storms will require sustained discussions, compromises and trade-offs among agencies, elected officials, and citizens and owners of properties in low-lying areas. One important part of the process will be to strengthen two-way flow of information between flood risk programme leaders, and citizens and property owners. Past flood control efforts had a strong “top down” dimension; this approach should be replaced by more vigorous and systematic twoway flow of information and discourse, with emphasis on helping citizens better understand flood risks and the full range of flood preparation and mitigation options. Modern technologies for addressing flood risks include: mobile levee systems that can be erected in hours, or days, flood risk communications initiatives, and better, relatively inexpensive software for visualization to enhance collaborative dialogue and mutual learning. The USACE is positioned to play a leadership role in more vigorous information exchange and systematic conversation, and development and implementation of innovative technologies for improved understanding of flood risks and the value of mitigation and preparedness measures. This will help citizens and property owners become better aware of the nature of flood risks, the inevitability and benefits of floods, and available flood preparedness options. One goal is greater “shared responsibility” and partnership among government agencies, communities and citizens. Many US communities currently are working with US federal agencies, including FEMA and the USACE, and their respective states, toward a better understanding and communication of flood risks, and better preparedness and to accepting more responsibility at the household level. The USACE looks to other federal agency and state initiatives, and academia and the flood risk literature and research programmes, to become better informed and capable in promoting more useful flood risk initiatives. The USACE, for example, has conducted several multi-hazard “tournament” exercises across the US to convene stakeholder groups to engage in decision support system (DSS)-based conversation regarding watershed management, more widespread appreciation of flood risk, and enhanced mitigation and preparedness activities.
Measuring objectively and accurately the impacts of this shifting approach to addressing flood risks is, not surprisingly, a difficult proposition. Nevertheless, anecdotal evidence and a variety of innovative research initiatives and federal, state, and community programmes and activities, provide evidence of increasing acceptance and promotion of flood risk programmes less reliant on dams, levees, and other structures. There is no single experiment or laboratory for the simulation, conduct or evaluation of these changing approaches to managing US floods. At the same time, many US cities that are adopting non-structural approaches are showing signs of resilience to floods. The city of Cedar Rapids, Iowa, for example, in October 2016 experienced its second-largest flood of record. The largest flood was in 2008, and the city took many steps following the 2008 event to increase resilience. The 2016 event resulted in zero fatalities, the city had moved many people and structures out of the floodplain area, and most downtown businesses were back on-line within 10 days after the flood crest had passed (having used to very good effect mobile levee systems to help protect downtown commercial properties).
The barriers to innovation – and the solutions
Generally speaking, a meaningful shift and adoption of non-structural approaches to managing floods will require changes in actions, perceptions, and thinking of agencies, elected officials, and citizens and the private sector. The traditional, primarily top down, structural approach to addressing floods had many successes and will remain appropriate and useful in some settings. Construction projects with large flood protection structures offer rewards and incentives to many entities. The fiscal reality, however, is that fewer of these projects will be constructed in the future. Large structures can entail a considerable infusion of federal money and jobs to a locale. Further, many citizens and other entities favour this approach to floods, and there remains widespread perception that flood risk can be eliminated by construction of a ‘flood control’ levee. These measures have historically been more common, and are favoured for a number of reasons. An important reality is that the US Congress, which authorizes Corps projects and provides funding to the agency, often has a strong preference for traditional, structural approaches to addressing flood risks, as compared to less expensive, and perhaps more complex, non-structural approaches. Potential ways to address these barriers include sustained educational and communication efforts, investment in resources for mitigation and preparedness efforts, systematic monitoring of the financial and environmental successes of non-structural initiatives to help demonstrate value to key entities in decision making process, for example the US Office of Management and Budget.