A Call to Enhance the Resiliency of the Nation’s Water Management

Water and floodplain management over the preceding half century has struggled with growing conflicts over water supplies, ongoing encroachment into flood-prone areas, increasingly limited operational flexibility of multipurpose reservoirs, and a decline in river-floodplain ecosystems and a loss in the economically important services they provide. Significant challenges and trends include:

Although we clearly acknowledge the social benefits from investments in dams and levees, we question whether status quo approaches to water and floodplain management are capable of addressing the diverse and interacting challenges facing the nation. The previously cited trends emphasize the growing strains on the nation’s water governance and infrastructure—also noted by others (e.g., Sheer 2010)—and illustrate the urgency of finding innovative approaches to contemporary water-management problems. The challenge of the 21st century is to make the most effective use of our legacy capital investment in water infrastructure by adjusting its design and operation to meet the needs of today and tomorrow.

Key to addressing this challenge is an evolution of water management toward IWRM, including greater emphasis on natural processes, such as river flows and seasonal river-floodplain connectivity. Toward this end, we propose steps to reexamine reservoir operations (water management) and advance integration of river-floodplain (flood-risk) management, and to reestablish sufficient natural river processes to restore the ecological integrity of our river systems and the valuable services they provide. First, we return to the Green River and describe the integrative solution devised by the engineers and ecologists that coordinates reservoir operations and floodplain management to achieve a broader set of objectives.

The group that was seeking solutions for the Green River was not convened to address a regulatory mandate or legal action. Instead, they recognized that the water-control plan guiding the dam’s operations had not been revised in its 30 years. The Corps, The Nature Conservancy, and other partners shared a common interest in changing operations for environmental benefits. In essence, they were probing the dam’s operational flexibility and seeking alternatives that could meet downstream environmental objectives while still fulfilling its authorized purposes (primarily flood control, but also recreation and water supply). After a few years of collaborative study, modeling, and test releases, the water control plan for the Green River Dam was revised and formally adopted, the first time the Corps had done so solely for environmental purposes. The changes in reservoir operations restored critical components of the natural hydrograph to benefit the downstream river, floodplain, and Mammoth Cave ecosystems. Although the plan was a notable accomplishment, even more compelling is the fact that the revised water-control plan gave up 5% of the original reservoir flood pool without increasing the downstream flood risk. Private and public funding of targeted and voluntary floodplain acquisitions and easements downstream of the reservoir helped to maintain equivalent levels of flood protection and to increase the operational flexibility of the dam. Furthermore, the revised operations extended economically important recreational access to the reservoir by 6 weeks each year.

The Green River provides a tangible demonstration of the premises we put forth here: First, strategic reconnection of floodplains can allow “green infrastructure” to complement the traditional “gray infrastructure” of dams and levees. Second, reallocating reservoir water storage, in coordination with innovations in downstream floodplain management, can improve economic productivity, restore ecosystem health and services, and enhance the resiliency of the nation’s water-management systems. These ideas are worthy of much broader consideration and investigation, even as the long-term benefits on the Green continue to be assessed. Although the Green has relatively limited water-management conflicts or constraints, other projects from around the nation also highlight the opportunities and potential benefits of both revising reservoir operations and improving the integration of river-floodplain management, including relying less on hard infrastructure and more on the natural infrastructure of connected river floodplains.

In the following, we offer a set of principles that describe the potential benefits of greater reliance on the green infrastructure of floodplains, as well as the ability for floodplain reconnection to facilitate a reallocation of current reservoir storage to re-optimize reservoirs’ societal benefits. These principles merit further investigation and test applications to evaluate underlying assumptions and devise technical, economic, and policy solutions. The Corps and The Nature Conservancy—individually and together—are working on a number of research and applied projects related to these principles, some of which are noted as examples.

We acknowledge that the vision presented here faces obstacles to its implementation. To be viable, proposed changes in policies and programs must respect private property rights and, where necessary and appropriate, provide equitable compensation for changes in water and floodplain land management. However, the status quo in water and floodplain management is not meeting the needs and expectations of the nation. Failing to develop and implement innovations today only perpetuates and exacerbates the risks to our people, economy, and environment and ensures that options for adaption will become more constrained and expensive. But we are confident that this country remains highly capable of technical and policy innovations and believe that the questions and investigations previously outlined will be central in defining a more resilient way forward.

We close by noting that our proposals are not radical, or even very new. In fact, the basic framework we are proposing was laid out more than 70 years ago, as Major General Jadwin proposed giving the Mississippi River “the room it needs, and to accord with its nature, must have the extra room laterally” (U.S. House of Representatives 1927); and in Gilbert White’s seminal work, Human Adjustment to Floods (White 1942), in which he emphasized the need to balance structural and non-structural approaches by stating that “Dealing with floods in all their capricious and violent aspects is a problem of adjusting human occupance to the flood-plain environment so as to utilize most effectively the natural resources of the plain, and, at the same time, of applying feasible and practicable measures for minimizing the detrimental impacts of floods.”

The nation is clearly indebted to both Major General Jadwin and Dr. White for their prescient calls for more balanced and comprehensive flood management. Although their proposals may not offer a full blueprint for the model of sustainability that we describe here (e.g., Jadwin focused only on flood control and navigation, not on environmental values), they do offer the foundation. Building on this foundation, we can design more broadly sustainable systems through technical, policy, and financial innovations to integrate gray and green infrastructure. Collectively, these innovations will better protect and enhance the resiliency of our communities and regional economies while strengthening the health and productivity of our river systems. Whether implemented at the broad scale of the Mississippi or on a much smaller river, we hope that decades from now, we can look back at that meeting on the banks of the Green River and recognize it as an important step toward achieving this shared vision of more sustainable and integrated management of our rivers and floodplains.