Updated December 9, 2019
Dam Safety: Federal Programs and Authorities
In recent years, several incidents have highlighted the
they were in need of rehabilitation (i.e., to bring up to
public safety risks posed by the failure of dams and related
standard) or repair.
facilities. From 2015 to 2018, over 100 dams breached in
North Carolina and South Carolina due to record flooding.
The Association of State Dam Safety Officials estimated
In 2017, the near failure of Oroville Dam’s spillway in
that the total cost to rehabilitate nonfederal and federal
California resulted in a precautionary evacuation of
dams in the NID would exceed $70 billion. Of this estimate,
approximately 200,000 people and cost more than $1.1
the cost to rehabilitate high hazard potential dams is $3
billion in emergency response and repair. The 2019 failure
billion for federal dams and $19 billion for nonfederal
of Spencer Dam in Nebraska resulted in the first dam-
dams.
failure fatality in the nation since 2006. In response to these
incidents, Congress may consider additional oversight and
What Is the Federal Role?
legislation that could improve dam safety.
The federal role in dam safety encompasses: (1) support for
state dam safety efforts; (2) support for federal dam safety;
This In Focus summarizes the U.S. dam inventory,
(3) regulation of certain nonfederal dams, and (4)
rehabilitation and repair estimates, federal dam safety
rehabilitation and repair for certain nonfederal dams.
activities, and related issues for Congress. For more
detailed information, see CRS Report R45981, Dam Safety
Support for State Dam Safety
Overview and the Federal Role.
Every state (except Alabama) has established a regulatory
program for dam safety, as has Puerto Rico. State dam
National Inventory of Dams
safety programs typically include safety evaluations of
The National Inventory of Dams (NID)—maintained by the
existing dams, review of plans and specifications for dam
U.S. Army Corps of Engineers (USACE)—catalogs
construction and major repair work, periodic inspections of
information from 50 states, Puerto Rico, and federal
construction work on new and existing dams, reviews and
agencies on most of the nation’s dams. The NID lists more
approval of environmental action plans, and emergency
than 90,000 dams. Federal government agencies (e.g.,
preparedness activities with local officials and dam owners.
USACE, U.S. Forest Service) report owning approximately
The dam owners ogenerally are responsible for the safety,
3% (2,717) of the dams in the NID, including some of the
rehabilitation, and repair of their dams; selected states
largest dams in the United States. The majority of NID-
provide a limited amount of assistance for these activities.
listed dams are owned by private entities, state and local
governments, and public utilities. Although states have
The main source of federal support for state dam safety
regulatory authority for more than 69% of NID-listed dams,
programs is the National Dam Safety Program (NDSP),
the federal government plays a key role in dam safety for
operated by the Federal Emergency Management Agency
both federal and nonfederal dams.
(FEMA). Authorized in 1996 by the National Dam Safety
Program Act, as amended (33 U.S.C. §§467f et seq.),
Of the dams in the NID, about 17% (15,629) are classified
NDSP activities include providing dam safety information
as high hazard potential (i.e., the loss of at least one life is
resources and training, facilitating information exchanges,
likely if the dam fails). The overall number of dams
and supporting state dam safety programs with grant
classified as high hazard potential has increased in the past
assistance. FEMA distributes around $7 million annually in
decade (mostly due to development around dams, not new
dam safety program grants to 49 states and Puerto Rico to
construction of dams). The NID also includes dams that are
support their dam safety activities.
deemed not a risk human life: significant hazard potential
dams could cause economic loss or environmental damage,
Support for Federal Dam Safety
and low hazard potential dams could pose limited risk and
The federal government has statutory responsibilities for
must meet a size threshold.
the monitoring, upkeep, rehabilitation, and repair of
federally owned dams. The major federal water resource
Dam Rehabilitation and Repair Needs
management agencies, USACE and the Bureau of
Dams were built to engineering and construction standards
Reclamation (Reclamation), own 42% (1,153) of federal
and regulations corresponding to the time of their
dams, including many large dams:
construction. Over half of the dams with information on
their age reported in the NID were built more than fifty
 USACE operates more than 700 dams, many with a
years ago. Some dams, including older dams, may not meet
primary purpose of flood risk reduction. USACE
current dam safety standards, which have evolved over time
implements a dam safety program consisting of
as scientific data and engineering have improved. In 2018,
inspections and risk analyses for all USACE dams that
the NID listed about 2,384 high hazard potential facilities
indicate the level of investment needed. In FY2018,
with structural ratings of poor or unsatisfactory, meaning
USACE funded $268 million in work on 10 dam safety
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Dam Safety: Federal Programs and Authorities
construction projects and funded dam safety studies at
removal). To be eligible for assistance, dams must have
39 projects. As of FY2019, USACE estimated a backlog
been built using selected USDA funds and must now pose a
of $20 billion for dam safety rehabilitation and repair.
public health or safety concern. The program covers up to
65% of the total rehabilitation cost. Since the program was
 Reclamation owns more than 400 dams in the 17 states
first authorized in 2000, Congress has appropriated more
west of the Mississippi River. Reclamation’s dam safety
than $700 million for these projects through FY2019.
program provides inspections and authorizes
rehabilitation and repairs to qualifying projects at
The USACE Rehabilitation and Inspection Program (RIP,
Reclamation dams. In FY2019, Congress appropriated
or the P.L. 84-99 program) is primarily used for levees but
$71 million to fund 18 dam safety projects. As of
also provides federal support for nonfederal dams that meet
FY2019, Reclamation estimated that the current
certain criteria (e.g., storage capacity for a 200-year flood
portfolio of dam safety modification projects through
event). RIP may provide assistance for flood control works
FY2030 would cost between $1.4 billion to $1.8 billion.
if a facility is damaged by floods, storms, or seismic
activity. As part of RIP, USACE periodically inspects
The remaining federal dams are owned by the Forest
participating facilities to ensure their owners are meeting
Service, Bureau of Land Management, U.S. Fish and
USACE maintenance standards (USACE considered 33
Wildlife Service, Department of Defense, Bureau of Indian
dams active in RIP in 2017). Because annual appropriations
Affairs, Tennessee Valley Authority, Department of
for RIP typically are insufficient to address numerous or
Energy, and International Boundary and Water
costly repairs, major repairs under this authority sometimes
Commission. In overseeing these dams, federal agencies
are provided through supplemental appropriations acts.
follow FEMA’s Federal Guidelines for Dam Safety.
Issues for Congress
Federal Regulation of Nonfederal Dams
Congressional support for the federal role in dam
Congress has enacted legislation to regulate selected
rehabilitation and repair traditionally has been focused on
nonfederally owned dams, including hydropower projects,
rehabilitation of federal facilities and support for state dam
certain mining activities, and nuclear facilities and
safety programs. Some have argued for an increased federal
materials. These nonfederal facilities and activities may use
role in nonfederal dam safety due to the potential loss of
dams for certain purposes. For example, the Federal Energy
lives and the large federal outlays in emergency spending
Regulatory Commission (FERC) has the authority to issue
that might be necessary if a dam failure were to occur.
licenses for the construction and operation of nonfederally
However, some may argue against encroaching on state and
owned hydroelectric projects, which may include dams.
local sovereignty (for example, land use and zoning
FERC staff inspect regulated dams at regular intervals, and
authority) and against the potential growth of the federal
the owners of certain dams are required to conduct more
government’s role.
thorough inspections. If a deficiency is found, FERC would
require the project owner to remediate the deficiency and
Congress may evaluate the level and allocation of
may require immediate risk-reduction measures (e.g.,
appropriations to federal dam safety programs, project
reservoir drawdowns). Other federal agencies regulating
modifications of federal dams, and financial assistance for
nonfederal dams include the Mine Safety and Health
both nonfederal dam safety programs and nonfederal dams.
Administration, the Office of Surface Mining Reclamation
Individual dam rehabilitation and repair costs can range
and Enforcement, and the Nuclear Regulatory Commission.
from thousands to hundreds of millions of dollars; many
nonfederal dam owners are not willing or able to fund these
Rehabilitation and Repair of Nonfederal Dams
costs. Congress may consider the tradeoffs in focusing
In FY2019, Congress appropriated $10 million for FEMA’s
federal resources on nonfederal dams versus federal dams,
High Hazard Dam Rehabilitation Grant Program, which
for which several agencies have stated financial need for
was authorized by the Water Infrastructure Improvements
rehabilitation and repair.
for the Nation Act (P.L. 114-322) to provide funding
assistance for the repair, removal, or rehabilitation of
Congress may revisit current policies for the disclosure of
eligible high hazard nonfederal dams. Congress authorized
dam safety information when considering the federal role in
the program to provide technical, planning, design, and
providing dam safety risk and response information to the
construction assistance in the form of grants to nonfederal
public (including those living downstream of dams) while
sponsors. FEMA may provide assistance with non-disaster
maintaining security of these structures. According to some
grants (e.g., Preparedness Grant Program, Pre-Disaster
advocacy groups, many Americans are unaware that they
Mitigation Program, and Flood Mitigation Assistance
live downstream of a dam. Dam safety processes and
Program) to reduce the flood damage that a dam failure
products (e.g., inspections, emergency action plans, and
could cause, or it may provide grants for these purposes
inundation maps) are intended to support decisionmaking
after a presidentially declared disaster (e.g., Hazard
and enhance community resilience. Some of these products
Mitigation Grant Program and Public Assistance Program).
may not be readily available to all community members
because such information generally is restricted from public
Separately, the U.S. Department of Agriculture (USDA) has
access.
authority under the Watershed Rehabilitation Program (P.L.
106-472, as amended) to provide financial and technical
Anna E. Normand, Analyst in Natural Resources Policy
assistance for the planning, design, and implementation of
IF10606
dam rehabilitation projects (including upgrading or
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Dam Safety: Federal Programs and Authorities


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https://crsreports.congress.gov | IF10606 · VERSION 7 · UPDATED

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