Background

Located within the Department of Defense, the Corps has both military  and civilian responsibilities. Through its Civil Works program, the Corps  plans, designs, constructs, operates, and maintains a wide range of water  resources infrastructure projects for purposes such as flood control,  navigation, and environmental restoration. The Civil Works program is  organized into three tiers: a national headquarters in Washington, D.C.;  eight regional divisions that were established generally according to  watershed boundaries; and 38 districts nationwide (see fig. 1).
Corps headquarters primarily develops policies and provides oversight.  The Assistant Secretary of the Army for Civil Works, appointed by the  President, establishes the policy direction for the Civil Works program.
The Chief of Engineers, a military officer, oversees the Corps’ civil works  operations and reports on civil works matters to the Assistant Secretary of  the Army for Civil Works. The eight divisions, commanded by military  officers, coordinate civil works projects in the districts within their  respective geographic areas. Corps districts, also commanded by military  officers, are responsible for planning, engineering, constructing, and  managing water resources infrastructure projects in their districts.  Districts are responsible for coordinating with the nonfederal sponsors,  which may be state, tribal, county, or local governments or agencies.  Each project has a project delivery team of civilian employees that  manages the project over its life cycle. The team is led by a project  manager and comprises members from the planning, engineering,  construction, operations, and real estate functions.
In addition, the Civil Works program maintains a number of centers of  expertise and research laboratories to assist the Corps divisions and  districts in the planning, design, and technical review of civil works  projects. The Corps established these centers to consolidate expertise,  improve consistency, reduce redundancy, and enhance institutional  knowledge, among other things.
Unlike many other federal agencies that have budgets established for  broad program activities, most Corps civil works funds are appropriated  for specific projects. In general, the Corps receives “no-year”  appropriations through the Energy and Water Development  Appropriations Act—that is, there are no time limits on when the funds  may be obligated or expended, and the funds remain available for their  original purposes until expended. The conference report accompanying  the annual Energy and Water Development Appropriations Act generally  lists individual projects and specific allocations of funding for each project.  Through this report, the appropriations committees essentially outline  their priorities for the Corps’ water resources projects. Congress directs  funds for many individual projects in increments over the course of  several years.

		Steps for Developing Corps Projects

The Corps is responsible for planning, designing, and operating much of  the nation’s water resources infrastructure. To do so, the Corps generally  goes through a series of steps involving internal and external  stakeholders.

			The Corps’ Planning and Design Process

Usually, the Corps becomes involved in water resources infrastructure  projects when a local community perceives a need or experiences a  problem that is beyond its ability to solve and contacts the Corps for  assistance. If the Corps does not have the statutory authority required for  studying the problem, the Corps must obtain authorization from Congress  before proceeding. Studies have been authorized through legislation,  typically a Water Resources Development Act (WRDA), or, in some  circumstances, through a committee resolution by an authorizing  committee. Next, the Corps must receive an appropriation to study the  project, which it seeks through its annual budget request to Congress.
After receiving authorization and an appropriation, a feasibility study is to  be conducted. A Corps district office is to conduct a feasibility study, the  cost of which is generally shared by a nonfederal sponsor, which may be  a state, tribal, county, or local government, or agency. The feasibility  study investigates the problem and makes recommendations on whether  the project is worth pursuing and how the problem should be addressed.  The district office is to conduct the study and any needed environmental  studies and document the results in a feasibility report.
At specific points within the feasibility stage, a new infrastructure project  is to undergo a series of technical reviews at the district, regional, and  national level to assess the project’s methodology and to ensure that all  relevant data and construction techniques are considered. At the district  level, all decision documents and their supporting analysis for a new  project are to undergo a district quality control review by district  leadership. This review is to assess the science and engineering work  products to ensure that they are fulfilling project quality requirements. At  the regional level, decision documents are to undergo an agency  technical review by Corps officials from districts outside of the one  conducting the study. This review verifies the district quality control  review, assesses whether the analyses presented are technically correct  and comply with published Corps guidance, and determines whether the  documents explain the analyses and results in a reasonably clear manner  for the public and decision makers. In some instances, a new project  meeting certain criteria may also undergo an Independent External Peer  Review. For these Independent External Peer Reviews, the Corps is  required by law to contract with the National Academy of Sciences, a  similar independent scientific and technical advisory organization, or an  “eligible organization” to establish a panel of experts that will review a  project study. Several criteria are used for selecting peer review panel  members, including assessing and balancing members’ knowledge,  experience, and perspectives in terms of the subtleties and complexities  of the particular scientific, technical, and other issues to be addressed.
After going through various levels of review, depending on the project, the  Chief of Engineers is to review the report and decide whether to sign a  final decision document, known as the Chief’s Report, recommending the  project for construction. The Chief of Engineers is to transmit the Chief’s  Report and the supporting documentation to Congress through the  Assistant Secretary of the Army for Civil Works and the Office of  Management and Budget. Congress may authorize the project’s  construction in a WRDA or other legislation.
Most infrastructure projects are authorized during the preconstruction  engineering and design phase, which begins after the feasibility study is  complete. The purpose of this phase is to complete any additional  planning studies and all of the detailed technical studies and designs  needed to begin construction of the infrastructure project.  Once the  construction project has been authorized, the Corps seeks funds to  construct the infrastructure project through the annual budget formulation  process. As part of the budget process, the Army, with input and data  from Corps headquarters, division, and district offices, develops a budget  request for the agency. In fiscal year 2006, the Corps introduced what it  refers to as performance-based budgeting, which uses performance  metrics to evaluate projects’ estimated future outcomes and gives priority  to those it determines have the highest expected returns for the national  economy and the environment, as well as those that reduce risk to human  life. Congress directs funds for individual projects in increments over the  course of several years. If the infrastructure project has been  appropriated funds, the district enters into a cost-sharing agreement with  the nonfederal sponsor.

			The Corps’ Operations and Maintenance

Section 2035 of WRDA 2007 as amended (Pub. L. No. 110-114, § 2035 (2007), as  amended by Pub. L. No. 113-121, § 3028 (2014)) requires the Chief of Engineers to  ensure that the design and construction activities for hurricane and storm damage  reduction and flood damage reduction projects have a safety assurance review by  independent experts if the Chief of Engineers determines that such a review is necessary  to assure public health, safety, and welfare, prior to initiation of physical construction and  periodically thereafter until construction activities are completed. authorized purposes in consultation with interested stakeholders in the  area of the project that may be impacted by its operations. In addition to  water control manuals for individual projects, the Corps may also have  master water control manuals that outline the operations of a system of  projects. The Corps may also develop operational guidance for non- Corps projects if, for example, the Corps has responsibility for flood  control or other operations at that project. Water control manuals typically  outline the operating criteria and guidelines for varying conditions and  specifications for water storage and releases from a reservoir, including  instructions for obtaining and reporting appropriate hydrologic data.

		Weather-Related Data

The Corps uses a variety of hydrologic data—data relating to the  movement and distribution of water—and forecasting data in its planning,  designing, and operation of water resources infrastructure that can help it  plan for extreme weather events. Much of these data are collected by  other federal agencies as part of nationwide efforts to gather weather and  hydrologic data. Table 1 shows examples of the type of hydrologic data  collected by various federal agencies and used by the Corps.
Corps officials and reports by federal agencies have highlighted  limitations in some of the data the Corps uses in its planning, design, and  operations of water resources infrastructure. Examples include the  following:
Streamflow. The Corps uses streamflow information from the  National Streamflow Information Program in its planning, designing,  and daily operations. However, according to Corps officials and USGS  data, loss of streamgages due to funding constraints has reduced the  available information about streamflows. According to USGS, from  1995 to 2008, 948 critical streamgages with 30 or more years of  records were discontinued. Further, a USGS report noted that the loss  of long-record streamgages reduces the potential value of streamflow  information for infrastructure operations and design applications.  Streamgage data are also used to produce climate change  information upon which the Corps bases its adaptation planning.  Despite these losses, the Corps has a formal agreement to provide  funding to USGS to operate streamgages that provide data for the  Corps’ water management activities and in fiscal year 2013 provided  USGS with $18 million.
Precipitation related to extreme storms. Until 1999, the Corps used  NWS Hydrometeorological Reports (site-specific probable maximum  precipitation studies) for its designs. However, NWS discontinued  providing these services in 1999 due to lack of funding, and some  Corps officials said they have been using outdated data since that  time. In response, the Corps has worked with the Interagency Federal  Work Group on Extreme Storm Events since 2008 and established its  own Extreme Storm Team to address Corps data needs, as well as  the needs of other agencies.
Plains snowpack. The Corps uses plains snowpack data in its runoff  forecasting for operations.  The Corps and NWS have found  limitations in this snowpack data. For example, a NWS report  assessing the 2011 Missouri River flood found that modeled  information on snow-water equivalent is available, but observational  data are sparse and not always representative of basin-wide  conditions. WRRDA 2014 included a requirement that the Secretary  of the Army, in coordination with other specified agencies, carry out  snowpack and soil moisture monitoring in the Upper Missouri Basin.  As of June 2015, those agencies had not yet developed the  monitoring system due to funding constraints according to agency  officials.

		Executive Orders to Address a Changing Climate

Under Executive Orders 13514 and 13653, agencies are to create and  update climate change adaptation plans that integrate consideration of  climate change into their operations and overall mission objectives.  Specifically, Executive Order 13514, issued in 2009, directed agencies to  participate in an existing Interagency Climate Change Adaptation Task  Force. Based on the work of the task force, the Council on Environmental  Quality (CEQ) issued implementing instructions for the executive order in  March 2011. The instructions directed agencies to, among other things,  issue an agency-wide climate change adaptation policy statement and  submit their climate adaptation plans to CEQ and the Office of  Management and Budget. Executive Order 13653, issued in 2013,  directed agencies to continue developing and regularly updating their  climate adaptation plans.
In response to these executive orders, the Corps submitted its Climate  Change Adaptation Plans in 2012, 2013, and 2014 (adaptation plan). The  Corps’ adaptation plan is implemented, in part, through its Responses to  Climate Change Program. This program is charged with developing the  methods, tools, and guidance to improve the resilience of the Corps’ built  and natural infrastructure through a collaborative, proactive, nationally  consistent, and regionally sensitive framework and program of actions.  According to the adaptation plan, these actions include improving the  agency’s understanding of climate impacts to missions and operations,  assessing vulnerabilities, and identifying specific actions to minimize risk  and capitalize on opportunities to improve infrastructure resilience.  According to Corps documents, infrastructure resilience is the ability to  anticipate, prepare for, respond to, and adapt to changing conditions and  to withstand and recover rapidly from disruptions with minimal damage.  As directed by CEQ instructions and guidance implementing Executive  Order 13514, the Assistant Secretary of the Army for Civil Works released  the Corps’ policy regarding adaptation in June 2014.that “mainstreaming climate change adaptation means that it will be  considered at every step in the project life cycle for all USACE [U.S. Army  Corps of Engineers] projects, both existing and planned … to reduce  vulnerabilities and enhance the resilience of our water resource  infrastructure.” This policy also established the Corps’ Committee on  Climate Preparedness and Resilience to oversee and coordinate the  agency’s climate change adaptation planning and implementation.
In January 2015, Executive Order 13690 was issued establishing a  federal flood risk management standard, which applies to federal  actions—including the construction of facilities with federal funds—in, and  affecting, floodplains. Under the standard, certain new construction,  substantially improved structures, and substantially damaged projects  must meet a certain elevation level, among other things. Draft floodplain  management guidelines were issued in February 2015 and were available  for public comment through May 6, 2015. Within 30 days of the close of  this public comment period, Executive Order 13690 directed agencies to  submit an implementation plan to the National Security Council that  contains milestones and a timeline for implementation of the executive  order and standard. using appropriated funds to implement the standard until input from  Governors, Mayors, and other stakeholders has been solicited and  considered. According to the executive order, agencies should not issue  or amend regulations and procedures to implement the executive order  until after implementing guidelines are issued. Thus, it is unclear how the  standard will affect the Corps’ operations.
The National Security Council is the President’s principal forum for considering national  security and foreign policy matters with his senior national security advisors and cabinet  officials.

	The Corps Considers the Potential Impact of Extreme Weather in Its Planning and Operations of Water Resources Infrastructure Projects

The Corps addresses the potential impact of extreme weather events in  its planning and operations of water resources infrastructure projects in  various ways including updating and developing guidance to be used in  the planning process; using tools, such as water control manuals, in its  operation of projects; and through collaboration with key federal agencies  and stakeholders.

		Corps Guidance and Initiatives Call for the Consideration of the Potential Impacts of Extreme Weather Events in the Planning Process

The Corps considers the potential impacts of extreme weather in its  planning process by updating and developing guidance, as well as  incorporating the uncertainties of extreme weather events in planning for  new infrastructure projects, and through its Civil Works Transformation  Initiative. For example, in 2009, the Corps issued guidance for  incorporating sea level change in its planning, construction, and operation  of water resources infrastructure projects impacted by the rise and fall of  sea levels. This guidance, which was updated in 2011 and 2013, directs  Corps districts to consider three scenarios of potential sea level change  when designing and constructing new infrastructure, as well as managing  existing water infrastructure. According to Corps documents, sea level  change can have a number of impacts on coastal and estuarine zones,  including more severe storm and flood damages. In 2014, the Corps  issued additional guidance on how to evaluate the effects of projected  future sea level change on Corps projects and what to consider when  adapting projects to this projected change.incorporate sea level change into the planning process to improve the  resilience of projects and maximize performance over time.
This guidance is intended to  In addition, in May 2014, the Corps issued guidance for how to  incorporate potential impacts of extreme weather into the planning of  inland infrastructure projects in accordance with Executive Order 13653  and the President’s Climate Action Plan.purpose and objective for incorporating this consideration into current and  future studies as well as provides an example of how to incorporate new  science and engineering in hydrologic analyses for new and existing  Corps projects. Moreover, the guidance establishes a procedure to  perform a qualitative analysis of potential climate threats and impacts to  the Corps’ hydrology-related projects and operations. The guidance calls  for districts to conduct an initial screening-level qualitative analysis to  identify whether climate change is relevant to the project goals or design.  If climate change is determined to be relevant to the project goals or  design, the guidance directs districts to make an evaluation of information  about climate change impacts such as changes in processes governing  rainfall runoff or snowmelt. The information is intended to be used to help  identify opportunities to reduce potential vulnerabilities and increase  resilience as a part of the project’s authorized operations, as well as  identify any limitations or issues associated with the data collected.
The Corps also issued guidance in October 2014 on determining the  appropriate use of paleoflood information in its planning and operation of  water infrastructure. According to Corps guidance, useful information  can be gained from paleohydrology, or the evidence of the movement of  water and sediment in stream channels before continuous hydrologic  records or direct measurements became available. For example, this  information can be derived from high water marks, tree rings, and gravel  deposits, among other things, and can help Corps districts estimate flood  peak magnitudes, volumes and durations for flood damage assessments,  or evaluate design criteria. This guidance also notes that paleoflood  information may not be suitable for all projects such as, watersheds that  have been altered through time, either by geologic processes or by  human activity.
In addition to updating and developing guidance for planning and  operating water infrastructure, Corps headquarters officials told us that  they also have taken steps to incorporate uncertainty, such as that  associated with extreme weather, into their planning process through the  Civil Works Transformation Initiative. According to Corps documents, the  Civil Works Transformation Initiative began in 2012 to aid the Corps in  meeting current and future challenges and addressing the water  resources needs throughout the United States. As part of the Initiative,  the Corps updated its planning process in 2012 to help strengthen the  incorporation of risk into planning assumptions for feasibility studies on  new infrastructure projects. For example, Corps headquarters officials  told us that they have adopted a risk-informed approach to help address  uncertainty, such as that associated with extreme weather, by defining  the levels of risk associated with a variety of project designs. Corps  officials said, beginning in 2012, feasibility studies for new projects have  used this approach to identify risks, including extreme weather, which  may occur throughout the life cycle of a water resources project.  Headquarters officials told us that, under this approach, project delivery  teams must address risks associated with climate change in their project  planning documents. To help ensure that the appropriate weather and  climate data are being used in the planning process, since 2012, the  Corps’ external peer review process has asked experts to review the  project plans and note whether appropriate data and information were  used to respond to extreme weather risks. Corps officials told us that  independent external review questions relating to climate change differ,  depending on when they were prepared, as well as the type of input  provided by the project delivery team and district officials. Because the  Civil Works Transformation Initiative is not yet complete, it may be too  early to evaluate the impact of this initiative.

		The Corps Uses Water Control Manuals and Other Tools to Help Prepare for Extreme Weather

The Corps uses a variety of tools in its operations to help prepare for  extreme weather, including water control manuals and an automated  information system. Water control manuals, which outline the operation of  water storage at individual projects, or a system of projects, are used by  the Corps to prepare for extreme weather events. These manuals are to  outline the various types of weather-related data the Corps uses in its  daily operations, as well as when extreme weather events occur. The  manuals are also to describe the automated processes used in a data  exchange with USGS and the regional NWS center that provides weather  forecasts, rainfall information, and streamflow data, among other  information to the Corps to prepare for extreme weather events. In  addition, water control manuals include a description of the historical  information that is used for purposes of creating models to predict  streamflow and reservoir stages. Corps guidance, in the form of engineer  regulations, describes what is to be included in water control manuals,  such as directing districts to establish and outline special operational  practices during emergency situations, as well as a drought contingency  plan. According to Corps officials, this Corps guidance ensures that Corps  districts’ water control manuals are created in a standardized manner so  all districts are prepared for extreme weather events. Corps guidance  also directs districts to ensure that all authorized purposes of a project are  addressed in its operations and notes that operations must strike a  balance among those purposes, which often have competing needs.  According to the Corps’ engineer regulations, any operational priorities  among multiple authorized purposes during extreme conditions, such as  drought or flooding events, may need to be defined in water control  manuals.
According to the Corps guidance, water control manuals also must  contain provisions for the Corps to temporarily deviate from operations,  when necessary, to alleviate critical situations. According to Corps  officials, critical situations may include extreme weather events, such as a  flood or drought. For example, in December 2014, the Corps approved a  deviation from operations at Prado Dam in southern California, which  allowed the Corps to temporarily retain water captured behind the dam  following a rainstorm. This deviation, along with other deviations in the  southern California region, was in response to the drought that California  has experienced since 2011. According to Corps guidance, deviations are  meant to be temporary and, if a deviation lasts longer than 3 years, the  water control manual must be updated. Corps officials we spoke with  were unaware of any deviations that, as of May 2015, have lasted more  than 3 years.
Corps headquarters and district officials we interviewed said that some  water control manuals may need to be updated due to changing  conditions in the watershed; however, they also said that some manuals  in existence for many years may not necessarily need to be updated  since, in part, they allow for flexibility with changing weather trends.  Specifically, headquarters and district officials we spoke with said projects  that have not experienced a change in land use around the basin, a  change in climate patterns, or new weather-related information may not  need to be revised. Furthermore, headquarters officials said water control  manuals, including reservoir rule curves and drought contingency plans,  have proved relatively robust to the climate changes already observed in   According to these officials, when combined with the ability to  the West.temporarily deviate from operations, when necessary, there is flexibility to  respond to short-term and long-term needs based on the best available  information and science. The Corps is currently working to develop and  implement a strategy to update drought contingency plans to account for  climate change. According to Corps officials, the agency will complete its  strategy for updating these plans by fiscal year 2016.
Corps guidance directs districts to periodically review and revise water  control manuals, as necessary, to conform to changing requirements  resulting from land development in the project area, improvements in  technology, and the availability of new hydrologic data, among other  things. Some district officials said water control manuals have not been  consistently updated due to changing conditions in the watershed,  primarily due to funding constraints. Corps headquarters officials said  there is not a Corps-wide process in place to assess whether manuals  should be updated; rather, it is up to the discretion of the districts to do  so. Some district officials said that they had requested funding to update  water control manuals but did not receive the requested funding to  conduct such updates. We will continue to assess this issue.
The Corps has also established the Corps Water Management System  (CWMS), an automated information system supporting the Corps’  operations to, among other things, prepare for extreme weather. CWMS  contains various data, such as weather conditions, soil moisture, snow  accumulation, streamflow, and water level that can be used by the  districts to develop models of watershed and channel processes and to  forecast future availability of water. For example, CWMS allows the  districts to simulate different operational scenarios to determine which  one will more likely result in higher downstream water levels due to a  large storm. According to Corps documentation, information from the  simulation is intended to help the districts assess the economic,  environmental, life safety, and other consequences, such as those from  an extreme weather event, of different operational scenarios and lead to  better-informed operational decisions. For example, Los Angeles district  officials told us that CWMS models are being calibrated for expected  maximum flood conditions which can allow them to better forecast runoff  volumes in areas prone to extreme weather events. According to Corps  documents, CWMS also will support rapid flood forecasting by the district  and help reduce the potential for flooding in the basin. CWMS has been  deployed to 35 of 38 districts since 2009 but has not yet been fully  integrated into all Corps districts, and the watershed and channel models  have not been fully implemented as of June 2015. The Corps plans to  complete integrating CWMS into all districts by the end of 2015, and an  effort is under way to have the watershed and channel models fully  integrated by 2023 or earlier, depending on funding.

		The Corps Collaborates with Key Stakeholders to Plan and Operate Water Infrastructure

The Corps has taken steps to prepare for extreme weather through its  participation in various collaboration efforts with federal agencies and  other stakeholders at both the regional and national levels.
At the regional level, Corps district officials told us that their collaboration  with federal agencies and local stakeholders is sufficient for effective  planning and operation of water infrastructure. Corps officials told us they  regularly collaborate with federal agencies and local stakeholders to help  ensure that they have the weather and climate data needed to plan and  operate water infrastructure and to address extreme weather in a  coordinated manner. For example, Alaska district officials told us their  district has a long history of collaborating with NWS and USGS to monitor  data across the remote areas of Alaska and now collaborates with these  agencies using a geostationary satellite. Little Rock district officials told us  they participate with agency officials from USGS and NOAA, as well as  other stakeholders, at Tri-Agency Fusion Team meetings to discuss ways  to improve the accuracy of the data generated by the agencies and  improve the accuracy and utility of rainfall observations and river  forecasts. Savannah district officials told us they regularly communicate  with NWS officials in advance of and during extreme weather events.  Within certain regions, Corps district officials told us they regularly interact  with state and federal officials through the Silver Jackets program to,  among other things, identify gaps among agency programs, leverage  information and resources, and provide access to national programs such  as the Corps Levee Inventory and Assessment Initiative. The Corps is  also conducting regional pilot studies nationwide to test different methods  and frameworks for adapting to climate change in which they involve  numerous stakeholders. For example, four Corps districts completed an  Ohio River Basin pilot study in 2013 in which the districts worked with  more than 70 stakeholders, including federal and state agencies,  academia, and private entities. The pilot study considered the potential  effects of climate change on future management of water resources,  including 83 Corps dams, 131 levees and floodwalls, and 63 navigational  locks in the 204,000 square miles of the basin. As a result of this pilot  study, a consortium of basin interests convened the Ohio River Basin  Alliance to address common interests in water resources and basin-wide  climate change issues.
Corps district officials told us that they may also interact with state  agencies, universities, and private industry to collect data that may not be  collected by federal agencies. For example, Little Rock district officials  told us they have used the Community Collaborative Rain, Hail, and  Snow Network, in which precipitation data are collected by volunteer  citizens and published daily on the Internet by Colorado State University.  Walla Walla district officials have been participating with the University of  Washington since 2012 in support of the Columbia River Treaty analysis  that involves information on data collection, modeling, and trends on  future weather and climate changes predicted for the region. Some  districts told us they also have gained valuable and up-to-date technical  information on engineering and design techniques from private industry  associations and made key contacts at industry conferences. However,  all the districts we spoke with told us they face challenges in attending  weather-related conferences sponsored by entities other than the federal  government due to changes in Department of Defense conference  policies.
Corps officials also collaborate with other federal agencies and  stakeholders at the national level to identify data gaps that may exist and  disseminate critical water resource information and data. For example,  Corps headquarters officials have participated in the Climate Change and  Water Working Group, a working-level forum established to share  information and accelerate the application of climate information in water  management, among other things. Through this group, the Corps along  with local, state, and federal water management agencies, have  examined water user needs for climate and weather information for long-  and short-term water resources planning and management and have   We have previously reported the  issued two reports on their findings. Corps along with NOAA, USGS, and other stakeholders developed the  Federal Support Toolbox, a federal Internet portal, to provide current,  relevant, and high-quality information on water resources and climate  change data applications and tools for assessing the vulnerability of water  programs and facilities to climate change.available online through the Integrated Water Resource Science and  Services group and is maintained by the Corps with contributions from  more than 16 federal agencies and nongovernment partners. According  to agency officials, the Integrated Water Resource Science and Services  group consists of four core agencies (USACE, NWS, USGS, and the  Federal Emergency Management Agency) and is currently focused on  improvements of water forecasting and integration of related models and  databases.

	The Corps Has Assessed Certain Infrastructure Projects to Prepare for Extreme Weather Events

The Corps has assessed certain water resources infrastructure projects  to determine whether they are designed to withstand extreme weather  events. Specifically, the Corps has national programs in place to perform  risk assessments on dams and levees, as required by law, but, unlike  these programs, the Corps is not required to perform systematic, national  risk assessments on other types of infrastructure, such as floodwalls and  hurricane barriers and has not done so. However, Corps officials said  they have been required to assess such infrastructure after an extreme  weather event in response to statutory requirements. The Corps has also  performed some preliminary vulnerability assessments for sea level rise  on its coastal projects and is beginning to conduct vulnerability  assessments of inland watersheds to determine how a changing climate  is affecting those projects.

		The Corps Performs Risk Assessments on Dams and Levees but Does Not Assess Other Types of Infrastructure

The Corps performs risk assessments of its dams and levees through two  national programs—the Dam Safety Program and the Levee Safety  Program—but does not have similar programs in place for other types of  infrastructure. As part of its Dam Safety Program, from 2005 to 2009,  the Corps performed a screening of 706 of its 707 dams to determine  which of its five risk classifications those dams fell under—very high urgency, high urgency, moderate urgency, low urgency, and normal.This risk classification addresses the probability of failure and resulting  potential consequences due to failure. Part of the assessment determines  whether the dams are designed and operated in such a way that, during a  potential flood event, the downstream flooding would not be more severe  than flooding if the dam did not exist. The risk assessment also takes into  account the likelihood of an extreme weather event. According to Corps  officials, all Corps-operated dams will undergo periodic assessments  every 10 years because the risk at any given dam may change over time.  The Corps has also established the Risk Management Center as a  resource to manage and assess risks to dams and levee systems, and  the Dam Safety Modification Mandatory Center of Expertise to provide  technical advice, oversight, review, and production capability to districts  performing any dam modifications in response to the risk assessment.  The Dam Safety Modification Mandatory Center of Expertise also  maintains a list of subject matter experts in the field of dam safety whose  names are accessible via the Internet.
The Corps assesses the risk of its dams through the Dam Safety  Program, but not all dam safety modification projects have been funded.  More specifically, the Corps’ initial screening of dams, completed in 2009,  found that 18 dams fell under the very high urgency classification, 83  dams fell under the high urgency classification, 219 dams fell under the  moderate urgency classification, and the remaining 386 dams fell under  the low urgency classification. For those dams in the very high urgency,  high urgency, and moderate urgency classifications, the Corps guidance  directs that an Interim Risk Reduction Measures Plan be developed,  which is a temporary approach to reduce dam safety risks while long-term  solutions are being pursued. The Corps found that completing dam safety  modifications on its dams in the three most urgent classifications would  cost more than $23 billion. The cost for dam safety modifications for the  very high urgency classification was about $4.2 billion; the high urgency  classification cost was about $7 billion, and the moderate urgency  classification cost was about $12 billion. According to Corps officials, from  fiscal year 2009 through fiscal year 2014, the Corps received about $2.5  billion in appropriations to begin dam safety modification studies and  construction on 15 very high urgency dams. As of June 2015, dam safety  modification construction has been completed on seven very high  urgency dams, and the Corps was working on the other eight. Corps  officials we spoke with in two districts said that they recognize that dams  in other districts may fall into the very high urgency classification for  modifications, but the dams in their own district, which are in the high  urgency classification, are also at a high risk of failure should an extreme  weather event occur.
The Corps also operates the Levee Safety Program, which began in  2006. According to the Corps, although the Dam and Levee Safety  Programs are similar in their approach to risk assessments, the Levee  Safety Program has not progressed as quickly, largely because the Corps  owns and operates less than 20 percent of the 14,700 miles of levees that  fall under the program. Until 2009, the Corps collected information on  14,700 miles of levees for inclusion in the National Levee Database.  Since that time, the Corps has been conducting risk assessments of the  14,700 miles of levees that are included in the Levee Safety Program.  The 14,700 miles of levees are divided into 2,887 segments, and risk  assessments have been completed for about 43 percent of those  segments as of April 2015. The Levee Safety Program risk assessments  are to take into account the likelihood of an extreme weather event and  how a levee will perform during that event. Based on the risk  assessments that have been completed as of April 2015, 1 percent of  those levees are classified as very high urgency, 8 percent are classified  as high urgency, 27 percent are classified as moderate urgency, and 64  percent are classified as low urgency. Based on the risk assessments  completed, as of June 2015, the Corps has not begun making  improvements to any of the levees it owns and operates because it is still  conducting the risk assessments and will prioritize any improvements  once those assessments are complete. Improvements made to the non- Corps levees based on the results of the risk assessment are at the  discretion of the local sponsor, with advice from the Corps on risk  reduction measures.
Unlike the requirements for the Dam Safety and Levee Safety Programs,  the agency is not required to perform risk assessments on other types of  existing infrastructure, such as hurricane barriers and floodwalls, and it  has not yet conducted an inventory of other types of infrastructure.  According to Corps officials, the agency has not performed systematic,  national risk assessments on other types of existing infrastructure given  funding limitations (see table 2). However, the Corps has received  appropriations for and has been required to assess such infrastructure  after an extreme weather event, such as in the aftermath of Hurricane  Katrina in 2005 and Hurricane Sandy in 2012.
Subsequent to Hurricane Sandy, for example, the Corps released, in  November 2013, an assessment of the performance of specific projects  and, in January 2015, a more general assessment of the North Atlantic  coastline. The project-specific performance assessment evaluated 75  constructed coastal storm risk management projects in the Corps’ North  Atlantic Division, which extends from Maine to Virginia, 31 projects in the  Great Lakes and Ohio River Division, and 9 projects in the South Atlantic  Division. For the more general assessment, the Corps looked at the risk  along 31,000 miles of Atlantic Ocean shoreline from Virginia to New  Hampshire as a system. The Corps divided the area into multiple areas  of coastline that were hydraulically separate from one another, studying  the risk of flood, as well as the exposure of the populations, exposure by  population density, infrastructure density, vulnerability by socioeconomic  factors, and vulnerability of environmental resources and cultural  resources. This risk assessment identified, among other things, nine high- risk areas of the North Atlantic Coast that warrant additional analyses to  address coastal flood risk. As of June 2015, the Corps has made no  improvements to its projects based on the general risk assessment in the  Corps’ study of Hurricane Sandy, which was made final in January 2015.  However, according to Corps officials, many projects identified in the  project-specific assessment received funding for and received repair and  restoration through the Corps’ Flood Control and Coastal Emergencies  Program.
The Corps conducted these risk assessments following Hurricanes  Katrina and Sandy after receiving an appropriation for and being required  by law to conduct them, as the Corps does not generally receive funding  for broad program activities, such as risk assessments on infrastructure  other than dams and levees. However, the Corps has not worked with  Congress to develop a more stable funding approach, as we  recommended in September 2010, which could facilitate such risk  assessments. That report found that a more stable funding approach could improve the overall efficiency and effectiveness of the Civil Works  program. The department partially concurred with our recommendation,  stating that it would promote efficient funding. As the frequency and  intensity of some extreme weather events are increasing, without  performing risk assessments on other types of existing infrastructure,  such as hurricane barriers and floodwalls, before an extreme weather  event (e.g., using a risk-based model), the Corps will continue to take a   For this  piecemeal approach to assessing risk on such infrastructure. reason, we continue to believe our recommendation is valid.

		The Corps Has Conducted Some Vulnerability Assessments of Water Infrastructure Projects to Prepare for Extreme Weather Events

The Corps has conducted two nationwide screening level assessments to  assess its vulnerability to climate change in its management and  operation of water infrastructure. According to the Corps’ 2014 Climate  Adaptation Plan, these vulnerability assessments are necessary so the  Corps can address a changing climate and successfully perform its  missions, operations, programs, and projects in an increasingly dynamic  environment.
In 2013, the Corps began an initial project-level vulnerability assessment  for coastal projects relating specifically to sea level change. Teams from  21 Corps districts with coastal projects reviewed more than 1,431 projects  to determine the impact of sea level change at the 50- and 100-year  planning horizons for coastal projects.score based on science-based parameters to categorize the level of  impact that sea level change would have on each project. The Corps  completed these initial vulnerability assessments for coastal projects in  September 2014 and determined that 944 of the 1,431 projects appear to  be able to withstand future changes resulting from sea level rise, 94  projects may experience high or very high impacts as a result of sea level  rise, and 393 projects may experience a low or medium impact as a result  of sea level rise. As of June 2015, the Corps had begun prioritizing the 94  projects that may experience high or very high impacts as a result of sea   These projects were given a  level rise for a more detailed assessment. Corps officials said they do not  yet know when this prioritization will be completed.
As of June 2015, the Corps was piloting methods to conduct the more  detailed vulnerability assessment. In one pilot, through a vulnerability  assessment of a hurricane barrier in New England that was designed in  1962 to provide navigation and flood risk reduction benefits for the area  surrounding a harbor, the Corps found the project had experienced a 6- inch loss from its design elevation due to sea level rise. The hurricane  barrier was listed as having potentially high impact from sea level rise in  the screening assessment. The more detailed pilot assessment identified  a potential future loss of elevation of between 6 inches and 2 feet 3  inches by 2065. Based on Corps data, the change in sea level has  resulted in a reduction in the distance between the top of the water and  the top of the hurricane barrier from 17 feet at its design to 16.5 feet  currently, and potentially down to 14.25 feet within 50 years (see fig. 2).  According to Corps officials, these future changes in distance between  the top of the sea and the top of the hurricane barrier can result in a  greater risk of floods and more operations of the navigation gate, which in  turn reduces navigation reliability and increases maintenance costs. The  Corps had initially planned to release a draft report on the initial coastal  vulnerability assessment in December 2014 but, as of June 2015, the  final report had not been released. Corps officials said the final report will  likely be released in late summer 2015.
Corps officials acknowledge that the science is not yet available to  conduct project-level vulnerability assessments for inland projects.  However, the Corps initiated a study in 2012 that focused on how  hydrologic changes due to climate change may impact freshwater runoff  in some watersheds. As of June 2014, the Corps had identified the top 20  percent of watersheds that were most vulnerable for each business line   Corps officials said this is an initial  through this initial watershed study.screening level assessment that will lead to more detailed assessments  of the most vulnerable water resources infrastructure projects and those  with the highest potential impact from extreme weather events. The Corps  is working with an expert consortium of federal, academic,  nongovernmental organizations, and others to develop the climate and  hydrology information necessary to conduct project-level assessments.  Corps officials said that the consortium will develop the information  needed to perform the project assessments and that it is unclear how  long developing the necessary science will take.
According to the Corps’ 2014 Climate Change Adaptation Plan and Corps  headquarters officials, the inland and coastal vulnerability assessments  will be merged over the next several years and will be used to determine  how the Corps needs to manage and plan for new water resource  projects. As of May 2015, Corps officials told us that they did not have a  timeline for merging these assessments, in part because the climate and  hydrology information is not yet available.

	Agency Comments and Our Evaluation

We provided a draft of this report for review and comment to the  Departments of Agriculture, Commerce, Defense, and the Interior for  comment. These agencies did not provide written comments. In an e-mail  received on June 29, 2015, the audit liaison for NOAA at the Department  of Commerce provided technical comments for our consideration. In  addition, in oral comments received on July 2, 2015, the Corps’ point of  contact on the engagement provided technical comments for our  consideration. We incorporated these technical comments as appropriate.
We are sending copies of this report to the appropriate congressional  committees; the Secretaries of Agriculture, Commerce, Defense, and the  Interior; and other interested parties. In addition, the report is available at  no charge on the GAO website at http://www.gao.gov.
If you or your staff members have any questions about this report, please  contact me at (202) 512-3841 or fennella@gao.gov. Contact points for  our Offices of Congressional Relations and Public Affairs may be found  on the last page of this report. GAO staff who made key contributions to  this report are listed in appendix I.

Appendix I: GAO Contact and Staff Acknowledgments

	GAO Contact

	Staff Acknowledgments

In addition to the individual named above, key contributors to this report  included Vondalee R. Hunt (Assistant Director), Michael Armes, Cheryl  Arvidson, Kendall Childers, Christopher Currie, Cindy Gilbert, Emily Pinto,  Holly Sasso, Jeanette Soares, Colleen Taylor, and Patrick Ward.

Summary:
Why GAO Did This Study

The Corps plans, designs, and constructs water resources infrastructure, such as dams and levees. According to the U.S. Global Change Research Program, the frequency and intensity of extreme weather events are increasing. Much of the Corps' infrastructure was built over 50 years ago and may not be designed to operate within current climate patterns, according to the U.S. Geological Survey.
The Water Resources Reform and Development Act of 2014 included a provision for GAO to study the Corps' management of water resources in preparation for extreme weather. This is the first in a series of reports GAO is issuing on this topic. GAO's other reports will examine operations and dam and levee safety, which GAO plans to issue in fiscal year 2016. This report explores (1) how the Corps prepares for and responds to extreme weather events in its planning and operation of water resources projects, and (2) the extent to which the Corps has assessed whether existing water resources infrastructure is prepared for extreme weather events. GAO reviewed Corps guidance on planning, operations, and assessments, and interviewed Corps officials from headquarters and eight districts— selected, in part, on number of projects.

What GAO Found

The U.S. Army Corps of Engineers (Corps) considers the potential impact of extreme weather events in its planning and operations of water resources infrastructure projects by, among other things, updating and developing guidance on how to incorporate different extreme weather scenarios in its planning of projects. For example, in 2014, the Corps issued guidance on how to evaluate the effects of projected future sea level change on its projects and what to consider when adapting projects to this projected change. In addition, Corps districts prepare water control manuals, guidance outlining project operations. The Corps can approve deviations from the manuals to alleviate critical situations, such as extreme weather events. For example, in December 2014, the Corps approved a deviation from operations at a southern California dam, which allowed the Corps to retain rainwater to help respond to the state's extreme drought conditions.
The Corps has assessed certain water resources infrastructure projects to determine whether they are designed to withstand extreme weather events. Specifically, the Corps has national programs in place to perform risk assessments on dams and levees, as required by law. Unlike the requirements for dams and levees, the Corps is not required to perform systematic, national risk assessments on other types of existing infrastructure, such as hurricane barriers and floodwalls and has not done so (see table). However, the Corps has been required to assess such infrastructure after an extreme weather event in response to statutory requirements, as it did in November 2013 and in January 2015, after Hurricane Sandy. Also, the Corps has performed initial vulnerability assessments for sea level rise on its coastal projects and has begun conducting such assessments at inland watersheds.
Unlike federal agencies that have budgets established for broad program activities, most Corps civil works funds are appropriated for specific projects. However, the Corps has not worked with Congress to develop a more stable funding approach, as GAO recommended in September 2010, which could facilitate conducting risk assessments. The Corps partially concurred with this recommendation, stating that it would promote efficient funding. As the frequency and intensity of some extreme weather events are increasing, without performing systematic, national risk assessments on other types of infrastructure, such as hurricane barriers and floodwalls, the Corps will continue to take a piecemeal approach to assessing risk on such infrastructure.

What GAO Recommends

GAO previously recommended that the Corps work with Congress to develop a more stable funding approach. The Corps has not taken action, but GAO continues to believe the recommendation is valid. Agencies had no comments on a draft of this report.