Hydrologic processes are very sensitive to changes in temperature, which can affect the form of precipitation (rain, snow), precipitation intensity and volume, the timing and volume of runoff, and conditions that cause or enhance drought. Observed climate change and variability have affected USACE water resources management-related missions and operations. USACE has developed and implemented policy and guidance to ensure that we are able to continue to provide reliable services in changing conditions. For example, changes in drought intensity and frequency in the late 1970s prompted the development of policy and technical guidance to improve drought contingency planning in coordination with stakeholders, resulting in the release of Engineer Regulation (ER) 1110-2-1941, Drought Contingency Plans in 1981. In the mid 1980s, an analysis of changing sea levels conducted by experts and presented in the influential 1987 National Research Council Report Responding to Changes in Sea Level: Engineering Implications clearly demonstrated that local and regional changes in sea level had and could continue to impact the reliability and performance of coastal infrastructure. At that time, over half (about 150) USACE coastal jetties were over 50 years old and a quarter (about 75) were over 100 years old. Given the importance of coastal navigation and flood risk reduction infrastructure to economic development and public safety, USACE issued a guidance letter in 1986 requiring coastal evaluations to consider the impacts of changing sea levels. This was succeeded in 1989 by Engineering Circular (EC) 1105-2-186 titled Planning Guidance on the Incorporation of Sea Level Rise Possibilities in Feasibility Studies (pdf, 609 KB) and in 2000 by the Planning Guidance Notebook (Engineer Regulation (ER) 1105-2-100).
The early 1990s brought studies on the economic impacts of climate change and a conference reporting on regional sensitivity of water resources management and potential adaptive responses. By the early 2000s, watershed studies began to focus on water-related impacts form climate change both within and outside the USACE. Stakeholders such as the Western Governors' Association recognized the need to better manage water resources in a changing environment. A renewed emphasis on incorporating new and changing conditions was identified in the internal and external analyses following Hurricane Katrina. In 2007, USACE, together with the Bureau of Reclamation, the US Geological Survey, and the National Oceanic and Atmospheric Administration, began an effort to better understand the impacts of climate change and variability on water resources management, culminating in an interagency report Climate Change and Water Resources Management: A Federal Perspective , published as USGS Circular 1331 in 2009. Also published in 2009 was updated policy and guidance for changing sea levels, EC 1165-2-211, Incorporating Sea-Level Change Considerations in Civil Works Programs (pdf, 463 KB) and ER 1110-2-8160, Policies for Referencing Project Elevation Grades to Nationwide Vertical Datums. Both of these policies addressed land subsidence and changing sea levels that were identifies as contributing to the impacts of Hurricane Katrina. USACE has actively worked with partners and stakeholders since then to improve actionable science that underlies decision-making supporting continued reliable performance in changing conditions.
In June 2014, The Honorable Jo-Ellen Darcy, Assistant Secretary of the Army for Civil Works, released the USACE Climate Preparedness and Resilience Policy Statement (pdf, 3.17 MB). This policy statement reaffirms and supersedes the 3 June 2011 Adaptation Policy Statement (pdf, 201 KB). The Policy Statement says that "Mainstreaming climate change adaptation means that it will be considered at every step in the project life cycle for all USACE projects, both existing and planned… to reduce vulnerabilities and enhance the resilience of our water-resource infrastructure."The Policy Statement establishes the Assistant Secretary of the Army (Civil Works) as the agency official responsible for ensuring implementation of all aspects of this policy. Through this policy, USACE establishes the USACE Committee on Climate Preparedness and Resilience to oversee and coordinate agency-wide climate change adaptation planning and implementation. The Committee is chaired by the Chief, Engineering and Construction.
Mainstreaming adaptation, as described in the Policy Statement, combined with the actions taken to improve energy and water conservation and reduce greenhouse gas emissions as described in the USACE Strategic Sustainability Performance Plan prepared in response to Executive Order 13514, will help us adapt to impacts from climate change and mitigate climate change.
In mainstreaming adaptation, our goal is to develop practical, nationally consistent, legally justifiable, and cost effective measures, both structural and nonstructural, to reduce vulnerabilities and improve the resilience of our water resources infrastructure impacted by climate change and other global changes.
The USACE recognizes the very significant differences between climate change adaptation and climate change mitigation in terms of physical complexity, fiscal and material resources, level of knowledge and technical readiness, and temporal and geographic scale. Because of these differences, understanding and implementing climate adaptation policies and measures requires very different knowledge, skills, and abilities than implementing mitigation measures. As a result, the Climate Change Adaptation Steering Committee is chaired by the Chief, Engineering and Construction.
EO 13653, Preparing the United States for the Impacts of Climate Change, Rescinded by EO 13783
EO 13653 , released on 1 November 2013 and rescinded on 28 Mar 2017 by EO 13783 , supplements EO 13514 , which in turn was rescinded by EO 13693 on 25 March 2015. EOs 13514 and 13693 deal primarily with energy and water conservation and greenhouse gas emissions reductions, whereas EO 13653 dealt primarily with climate preparedness and to manage the effects of climate change on the agency's operations and mission in both the short and long term. As described above in the section under Policy, USACE activities to ensure reliable performance of agency missions in changing conditions predated EO 13653 and continue after it was rescinded. USACE reports on these activities in accordance with EO 13693.
USACE June 2015 Climate Change Adaptation Plan Update to 2014 Plan
This USACE 2015 Adaptation Plan (pdf, 6.23 MB; low-resolution version, 2.40 MB) is an update to the 2014 Adaptation Plan, and was submitted to CEQ and OMB as part of the USACE Sustainability Plan. This 2015 Adaptation Plan update reflects climate preparedness and resilience actions in the Climate and Natural Resources Priority Agenda and recommendations from the State, Local, and Tribal Leaders Task Force for Climate Preparedness and Resilience, released in fall 2014. This update also addresses EO 13677 (Climate-Resilient International Development), EO 13689 (Enhancing Coordination of National Efforts in the Arctic), EO 13690 (Establishing a Federal Flood Risk Management Standard and a Process for Further Soliciting and Considering Stakeholder Input), and EO 13693 (Planning for Federal Sustainability in the Next Decade).
2014 Climate Change Adaptation Plan and Report