Page 1 GAO-24-107493 Clean Water Act
Wetl
ands, streams, and other aquatic resources are critical to maintaining
healthy ecosystems. Wetlands support a number of valuable functions, including
flood controls, improving water quality, and providing wildlife with habitat. To
restore and maintain the integrity of these waters, discharging dredged or fill
material into waters of the United States—which can include wetlands and
streams—is generally prohibited without a permit from the U.S. Army Corps of
Engineers (Corps). For a Corps permit to authorize discharge, parties
responsible for it must generally avoid and minimize adverse impacts to
wetlands, streams, and other aquatic resources to the extent practicable. In fiscal
year 2023 alone, the Corps issued permits for permanent and temporary impacts
to more than 73,000 acres of aquatic resources.
For unavoidable adverse impacts, compensatory mitigation may be required to
replace the loss of wetland or aquatic resource functions to the extent
practicable, generally in the same watershed. Compensatory mitigation refers to
the restoration, establishment, enhancement, or—in certain circumstances—
preservation of wetlands, streams, and other aquatic resources for the purpose
of offsetting unavoidable adverse impacts that remain after achieving all
appropriate and practicable avoidance and minimization. Compensatory
mitigation includes activities such as planting trees and erecting in-stream
structures. Permittees may perform the work themselves (known as permittee-
responsible mitigation) or pay a third-party mitigator to improve or preserve
aquatic resources and assume responsibility for successful completion of the
mitigation project. The Corps issues permits for the discharge of dredged or fill
material into waters of the United States and as part of the permitting process
can require compensatory mitigation under section 404 of the Clean Water Act
and its implementing regulations. The Corps’ 38 district offices are responsible
for issuing these permits.
The Water Resources Development Act of 2022 includes a provision for GAO to
review the costs of carrying out compensatory mitigation activities borne by the
federal government, a permittee, or any other involved entity. (Pub. L. No. 117-
263, div. H, tit. LXXXI, § 8236(d)(2)(B)(iv), 136 Stat. 2395, 3772.) This report
discusses the types and amounts of costs for carrying out compensatory
mitigation activities borne by the federal government, third-party mitigators,
section 404 permittees, and any other involved entities, such as state
government agencies.
• Certain federal agencies and state environmental agencies incur costs for
reviewing and approving third-party mitigation projects and reviewi
ng
m
onitoring reports for those projects. Federal and state agencies may als
o
U.S. Government Accountability Office
Clean Water Act: Costs of Compensatory
Mitigation Activities for Losses of Aquatic
Resources
-24-107493
Report to Congressional Committees
25, 2024
