link to page 1 
Updated May 3, 2023
U.S. Army Corps of Engineers Nuisance Species Efforts
Introduction
USACE Nuisance Species Activities
Nuisance species are species that cause, or are likely to
USACE generally undertakes efforts to prevent or reduce
cause, economic or environmental harm or harm to human
the introduction and establishment of invasive species and
health. Nuisance species impact both terrestrial and aquatic
the proliferation of HABs at its projects, pursuant to its
ecosystems. As human societies have become more
project and programmatic authorizations (some of which
connected, opportunities for the spread of non-native
authorize specific activities), nationwide Invasive Species
nuisance species (i.e., invasive species) have increased
Policy Guidance, and engineering regulations. USACE
(e.g., navigation activities can transport species and
typically funds nuisance species work for individual
introduce them to multiple different watersheds and
projects through project funding lines in the Operation and
waterbodies). Many federal and nonfederal agencies
Maintenance (O&M) account; project planning documents
managing land and water undertake efforts to prevent the
address the nature of work at the project level. USACE also
introduction and spread of invasive species. Upon detection
pursues nuisance species research that may involve field
of nuisance species, agencies may devote resources to
studies at USACE projects. As part of its regulatory
control and/or eradication efforts.
responsibilities, USACE also may require permit applicants
to consider nuisance species control. In FY2022, USACE
Congress has authorized various programs for U.S. Army
spent an estimated $237.1 million on nuisance species
Corps of Engineers (USACE) nuisance species activities
activities; Figure 1 specifies this funding by response type.
and has expanded the scope of the authorizations as well as
the appropriations for these activities. This In Focus
Figure 1. USACE Estimated Spending on Nuisance
discusses USACE nuisance species control efforts,
Species Efforts by Response Activity, FY2022
including selected authorities, programs, and funding.
Effects of Nuisance Species
After introduction, invasive species may become
established and spread; once established, it can be costly
and difficult (or impossible, in some cases) to control or
eradicate them. For more information, see CRS In Focus
IF11011, Invasive Species: A Brief Overview.
Harmful algal blooms (HABs) also can affect aquatic
systems and their uses. Algal communities are naturally
occurring components of healthy aquatic ecosystems.
However, under certain environmental conditions—such as
increased temperatures and nutrient concentrations (e.g.,
nitrogen and phosphorus)—colonies of algae can grow
excessively (or bloom) and produce toxins, becoming
nuisance species. For more information, see CRS In Focus
IF10690, Freshwater Harmful Algal Blooms: An Overview.
USACE, part of the Department of Defense, develops and
maintains civil works projects in the United States,
Source: CRS, using FY2022 National Invasive Species Council Crosscut
principally to improve navigation, reduce flood and storm
Budget, at https://www.doi.gov/invasivespecies/crosscut-budget.
damage, and restore aquatic ecosystems. USACE is the
steward of approximately 12 million acres of public lands
Note: USACE estimates spending for fiscal years based on previous
and waters associated with hundreds of water resources
expenditures, projections of work, and known additions of funding.
projects nationwide. Nuisance species can affect USACE
projects by outcompeting beneficial species, clogging water
Updating USACE Nuisance Species Policies
pipes, and affecting water quality and recreation. Invasive
The John D. Dingell, Jr. Conservation, Management, and
species affecting USACE projects include Asian carp, zebra
Recreation Act (P.L. 116-9) and America’s Conservation
and quagga mussels, feral hogs, and hydrilla (an aquatic
Enhancement Act (P.L. 116-188) amended the Fish and
plant species), among others. In addition, HABs have
Wildlife Coordination Act (16 U.S.C. §§661 et seq.) to
affected the aquatic systems where USACE projects exist.
direct the Secretary of the Army to develop and implement
USACE projects can also serve as a vector for transporting
a strategic plan for an invasive species program to achieve
nuisance species that damage other water bodies.
an annual net reduction of invasive species populations on
https://crsreports.congress.gov
U.S. Army Corps of Engineers Nuisance Species Efforts
land or water managed by USACE. The Water Resources
under USACE’s O&M account and directed $18.0 million
Development Act of 2020 (WRDA 2022; Division AA of
of the funding to address HABs, including $5.0 million for
P.L. 116-260) further directed USACE to periodically
the HAB Demonstration Program.
update its Invasive Species Policy Guidance. USACE
published an updated guidance document in February 2023,
Removal of Aquatic Growth Program. The Removal of
which affirms collaboratively managing with partners both
Aquatic Growth Program is a navigation O&M authority as
aquatic and terrestrial invasive species and HABs. The
provided in several public laws to control nuisance plants
document also stated that USACE had drafted the strategic
that are negatively impacting USACE navigation projects in
plan mandated by the Fish and Wildlife Coordination Act,
Gulf Coast states, Georgia, and South Carolina. In FY2023,
which is to be used when finalized.
Congress provided $3.7 million for USACE to remove
aquatic growth in Louisiana and Florida at federal expense.
USACE Nuisance Species Programs
USACE has several programs that address nuisance species
Pilot Programs. WRDA 2020 authorized several USACE
activities. Congress has amended the authorized activities
pilot programs related to nuisance species. The act directed
under some of these programs and authorized pilot
USACE to carry out a pilot program to manage and prevent
programs. Congress funds these programs annually, usually
the spread of Asian carp in the Cumberland and Tennessee
at a level higher than the Administration requested.
River watersheds using innovative methods. The pilot
program received $650,000 total from FY2022 and FY2023
Aquatic Plant Control Program. Section 104 of the River
appropriations for the Aquatic Nuisance Research Program,
and Harbor Act of 1958, as amended (33 U.S.C. §610),
and USACE has stated that it is developing a management
authorizes the Aquatic Plant Control Program, a program
plan for the pilot program. The act also directed USACE to
for the prevention, control, and progressive eradication of
carry out a pilot program to identify and develop strategies
noxious aquatic plant growths and aquatic invasive species
for terrestrial noxious weed control on USACE-managed
in U.S. waters. The program supports research and
land. USACE allocated $100,000 in FY2023 from funding
development of management solutions for invasive aquatic
provided for its O&M account to its Stewardship Support
plants that affect USACE missions. The Water Resources
Program to conduct an assessment across USACE projects
Reform and Development Act of 2014 (P.L. 113-121) and
and to implement two control projects. WRDA 2020 also
subsequent WRDAs have amended this authority to also
amended 33 U.S.C. §610 (1) to authorize USACE to enter
require USACE to establish and operate watercraft
into partnerships to control or eradicate invasive species in
inspection and decontamination stations in selected river
certain western river basins and (2) to authorize a pilot
basins to prevent the spread of aquatic invasive species
program to manage invasive species at public facilities
(such as quagga and zebra mussels) at USACE reservoirs.
associated with USACE reservoirs in the Upper Missouri
These watercraft inspection stations are to be constructed,
River Basin. These two authorities remain unfunded as of
operated, and maintained with a 50% federal cost share.
FY2023 and are set to expire after FY2024.
Appropriations are authorized at $130.0 million annually
Example USACE Nuisance Species Project
for these stations. For FY2023, Congress appropriated
In some cases, Congress has authorized USACE to
$38.0 million for the Aquatic Plant Control Program under
USACE’s
undertake nuisance species control efforts at specific water
Construction account, including $16.0 million for
resource projects. An example is USACE efforts in the
watercraft inspection and decontamination stations.
Chicago area to control the transfer of aquatic invasive
species, including Asian carp, between the Great Lakes and
Aquatic Nuisance Research Program. The
the Mississippi River basins. Congress funded USACE’s
Nonindigenous Aquatic Nuisance Prevention and Control
construction and operation of underwater electric barriers in
Act of 1990, as amended (16 U.S.C. §4722), authorized the
the Chicago Sanitary and Ship Canal, which is a hydrologic
Aquatic Nuisance Species Research Program. An expansion
link between the Great Lakes and the Mississippi River.
of the former Zebra Mussel Research Program, the program
Congress further authorized the Great Lakes and
supports research on new methods for preventing,
Mississippi River Interbasin Study to evaluate potential
detecting, monitoring, and controlling invasive aquatic
methods to prevent aquatic invasive species transfer
species, as well as HABs, that impact navigable waters,
between the basins. Study recommendations included a
infrastructure, and associated water resources. USACE
“Technology Alternative,” consisting of nonstructural
disseminates this information to its field offices. Program
measures, an acoustic fish deterrent, an air bubble curtain,
activities do not require a nonfederal cost share.
an engineered channel, an electric barrier, and a flushing
Congress has recently authorized and funded new HAB
lock at Brandon Road Lock and Dam. In 2019, the USACE
activities under this program. WRDA 2018 (Title I of P.L.
Chief of Engineers signed a report recommending this
115-270) directed USACE’s Engineer Research and
alternative with a construction cost of $830.8 million
Development Center to implement a five-year HAB
(FY2019 levels) at a 65% federal cost share and operation
technology development demonstration program. WRDA
and maintenance at an 80% federal cost share. WRDA 2020
2020 authorized $25 million for a HAB Demonstration
authorized construction for the project at 80% federal cost
Program, which was amended further in WRDA 2022 (Title
share and WRDA 2022 further amended the cost share to
LXXXI of Division H of P.L. 117-263). USACE released
90% federal. The project received $273.7 million total in
implementation guidance for the HAB Demonstration
Construction appropriations in FY2022 and FY2023.
Program in 2022 and anticipates releasing a request for
Anna E. Normand, Analyst in Natural Resources Policy
proposals in FY2023. In FY2023, Congress appropriated
IF11666
$23.0 million for the Aquatic Nuisance Research Program
https://crsreports.congress.gov
U.S. Army Corps of Engineers Nuisance Species Efforts
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
United States Government, are not subject to copyright protection in the United States. Any CRS Report may be
reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include
copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you
wish to copy or otherwise use copyrighted material.
https://crsreports.congress.gov | IF11666 · VERSION 7 · UPDATED