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What is Adaptation?

Water resource managers must be able to be responsive to events not seen in the past, surprises, and other unexpected events, both natural and socioeconomic. In order to maintain the benefit of existing and proposed water resource projects in the changing climate, water resources managers must move from an expectation that the future will be similar to the past — or stationary — paradigm to one that more explicitly accounts for the dynamic nature of physical and socioeconomic processes.

Climate change is one of many global changes USACE faces in carrying out its missions to help manage the nation's water resources infrastructure. Water resource managers must make decisions that rely upon assumptions about future supplies, demands, weather, climate, and operational constraints at varying space and time scales. These decisions are made within the presence of various degrees of uncertainty. USACE must provide our stakeholders and partners with data and information that allows them to make risk-informed decisions as well.

The USACE climate and global change adaptation goal is to develop practical, nationally consistent and regionally tailored, legally justifiable and cost-effective adaptation measures, both structural and nonstructural, that will reduce vulnerabilities and improve resilience to these challenges (USACE Climate Change Adaptation Plan and Report 2011). Recognizing that, over time, uncertainty may decrease as we increase our knowledge of climate change, its impacts, and the effects of adaptation and mitigation options (including unintended consequences) water managers must establish decision processes that incorporate new information. The use of rigorous management in an adaptive fashion, where decisions are made sequentially over time, allows adjustments to be made as more information is known. The use of longer planning horizons, combined with updated economic analyses, will support sustainable solutions in the face of changing climate that meet the needs of the present without compromising the ability of future generations to meet their own needs.

USACE near-term priorities for climate change adaptation and mitigation include:

  • supporting the National Action Plan to Manage Freshwater Resources in a Changing Climate
  • developing and implementing a framework for climate change risk-informed decision-making
  • considering the critical needs of non-stationary hydrology
  • creating best practices guidelines for how to select from a portfolio of approaches to develop climate information for use in decision-making
  • refining vulnerability assessments, including bottom-up approaches at the project level
  • developing metrics and endpoints to measure adaptation effectiveness


The USACE follows the Intergovernmental Panel on Climate Change's (IPCC) definition of adaptation as adjustments or changes in decision environments undertaken with the objectives of enhancing resilience or reducing vulnerability to observed or expected changes in climate. USACE also understands that climate change is but one of many challenges facing water resources managers, so that an integrated approach to water resources management includes all significant drivers of change. Adaptation options include modifications to operations, demand management, and infrastructure changes, within the authorizations of USACE projects. The IPCC defines different types of adaptations (Fluet et al 2009):

  1. anticipatory (or proactive) adaptation: before the impacts of climate change
  2. autonomous adaptation: an unconscious response to climatic stimuli, triggered by climate changes
  3. planned adaptation: resulting from political decisions, and based on an awareness of changing conditions and that actions are necessary to ensure well-being
  4. private adaptation: initiated by individuals, families or private companies
  5. public adaptation: initiated and instituted by government at all levels
  6. reactive adaptation: put in place after the impacts of climate change

USACE Climate adaptation will encompass anticipatory, planned, public, and reactive adaptation, and will recognize the contributions of private adaptation

Plans and Reports

USACE Climate Change Adaptation Plan and Report 2011 (pdf, 1.99 MB), revised and submitted September 2011.

Final National Action Plan (NAP): Priorities for Managing Freshwater Resources in a Changing Climate (pdf, 27.85 MB) October 2011.

Draft National Action Plan to Manage Freshwater Resources in a Changing Climate (pdf, 1,8 MB) June 2011.


"US Army Corps of Engineers Approach to Water Resources Management Impacted by Climate Change" (pdf, 5.39 MB)
Authors: Jerry W Webb, PE, D.WRE; Theodore A Brown, PE; James C Dalton, PE; Kate White, PhD, PE; J. Rolf Olsen, PhD; Jeff Arnold, PhD; and Jason P. Giovannettone, PhD

"Developing a Decision Framework and Associated Tools for the US Army Corps of Engineers Infrastructure at Risk from Future Climate Change Effects" (pdf, 7.45 MB)
Authors: Jeff Arnold, PhD; Kate White, PhD, PE; Paul Wagner, PhD Joel Schlagel; Rolf Olsen, PhD; Mark Sudol, PhD


Fluet, M-J, L. Vescovi, A.I. Bokoye (2009) "Water and climate change: Citizen mobilization, a source of solutions."  The United Nations World Water Assessment Programme, Side Publications  Series, Dialogue Paper You are leaving a Federal Government web site. Click this icon for more information.

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Reviewed 20 June 2016


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