Hydropower Environmental Review Overview (9)

Information current as of 2023

A hydropower developer may need to comply with federal and state environmental review processes. A typical hydropower project will raise environmental issues that require permitting and/or regulatory approval from federal and state agencies. The environmental law in the United States is governed by federal law that is administered by both federal and state agencies, as well as state environmental laws that either complement federal law or go above and beyond it.

The National Environmental Policy Act (NEPA) was signed into law on January 1, 1970. NEPA establishes national environmental policy and goals for the protection, maintenance, and enhancement of the environment and provides a process for implementing these goals within the federal agencies. A developer will be required to go through the NEPA process if the project involves a "major federal action A major federal action is defined as “an action that the agency carrying out such action determines is subject to substantial Federal control and responsibility.” 42 U.S.C. 4336e (10). The level and scope of the NEPA review will vary depending on the nature of the project and to what degree the federal government will be involved. Some actions and projects will receive a categorical exclusion while others may require a full Environmental Impact Statement (EIS).

NEPA review is handled by a "lead agency." A “lead agency" is the federal agency responsible for writing the main NEPA document(s) and coordinating with any other federal, state, or tribal agencies. The lead agency is expected to follow the guidelines prescribed by NEPA in 42 U.S.C. 4336a. An EA must not be longer than 75 pages, not including appendices or citations and it must be completed within one year. 42 U.S.C. 4336a. An EIS has a page limit of 150 pages, not including appendices or citations, or if it is of extraordinary complexity the limit is 300 pages, not including any appendices or citations. An EIS must be completed within two years of the start date identified in 42 U.S.C. 4336a. The deadline may be extended by the lead agency in consultation with the applicant for only so much additional time as is necessary to complete the environmental document. 42 U.S.C. 4336a (g). If the deadline is not met for either an EA or an EIS, a project sponsor may file a written petition with a court to compel the agency to act more quickly. 42 U.S.C. 4336a (g)(3).

For many hydropower projects, the lead agency will be the Federal Energy Regulatory Commission (FERC). However, under certain circumstances the lead agency will be the Bureau of Reclamation (BOR), the U.S. Army Corps of Engineers (USACE), or a federal land management agency such as the United States Forest Service (USFS) or the Bureau of Land Management (BLM). A hydropower project may be required to undergo more than one NEPA review, each with a different lead agency. This would occur if, for example, USACE does not sign on as a cooperating agency for FERC review and instead completes a separate NEPA review for Section 404 permitting. An approach such as this would produce two distinct NEPA documents each potentially incorporating the contents of the other by reference.

A “cooperating agency” means any federal, state, local, or tribal agency other than a lead agency which has jurisdiction by law or special expertise with respect to any environmental impact involved in a proposal (or a reasonable alternative) for legislation or other major federal action significantly affecting the quality of the human environment. For example, where FERC is the lead agency for purposes of completing the NEPA process for hydropower development on federal land, other federal agencies with jurisdiction or special expertise take on the role of a cooperating agency.

To comply with federal environmental regulation, the developer is also required to comply with state environmental laws. Many states have adopted their own environmental laws and regulations.

Potential environmental impacts from hydropower development that may occur during the site evaluation, construction, and operation phases of the project include:

Vehicle emissions, volatile organic compound (VOC) releases from storage and transfer of vehicle/equipment fuels, carbon monoxide, nitrogen oxides and particulates from blasting activities, and fugitive dust from clearing, grading, excavating, and vehicle and equipment traffic;
Noise disturbances from drilling, blasting, vehicle traffic, turbine, generator, and transformer can impact migration, feeding, and reproduction patterns in species;
Direct and indirect impacts to cultural resources from surface disturbances or excavation, erosion, sedimentation, increased human access can increase exposure to contaminants, and interfere with behavioral activities of species;
Direct and indirect impacts to ecological resources (vegetation, wildlife, aquatic biota and their habitats) from introduction of invasive species from vehicle traffic, fugitive dust, erosion and runoff from excavation can limit a plant’s ability to photosynthesize, and impact habitats. Construction of roads, canals, pipelines, and transmission rights-of-way can fragment wildlife habitats affecting feeding and reproduction behaviors. Construction of intakes and dams can significantly alter the river leading to habitat loss and degradation for aquatic species; and
Water quality could also be affected by activities that cause soil erosion, including construction of the intake and dam, which could increase turbidity and suspended sediment transport.

Office of Indian Energy and Economic Development – Tribal Energy and Environmental Information Website.

Environmental Review Overview Process

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