West Branch Valley Flood Protection Association v. Stone

In West Branch Valley Flood Protection Association v. Stone, a nonprofit association sued the United States Army Corps of Engineers (Corps) alleging violations of the National Environmental Policy Act (NEPA) and the National Historic Preservation Act (NHPA) as a result of the Corps' construction of dikes and levees to protect the city of Lock Haven, Pennsylvania, from flooding. Planning for the project began in the mid-1970s when the Corps developed an environmental impact statement (EIS) proposing various alternative flood protection measures. The Corps periodically refined the original project as new information developed and, in 1980, supplemented the EIS.

In 1987, the Corps changed the design of the levee, conducted an environmental assessment (EA) of the project's impact, and made a finding of no significant impact. The Corps published a second EA in 1990 addressing changes in the levee alignment intended to avoid a hazardous waste site and, once again, made a finding of no significant impact. The Corps additionally published a supplemental information document to clarify environmental decisions involved in the project. As part of its environmental review process, the Corps also conducted eight studies of the archeological resources in that area and entered into a Memorandum of Agreement (MOA) with the Pennsylvania State Historic Preservation Office (SHPO), the Advisory Council on Historic Preservation, and the local flood protection authority.

Plaintiffs' NEPA argument focused on the Corps' decision not to supplement the 1975 EIS as required by the regulations implementing NEPA where there are "substantial changes to the proposed action or significant new circumstances." The court found that the Corps' decision not to supplement the EIS was neither arbitrary nor capricious. Reviewing the numerous studies conducted by the Corps during the lengthy planning for the project, it found that the studies did not pose "significant new information" warranting a supplemental EIS.

In a related NEPA argument, plaintiffs alleged that the EIS process had to be reopened because the Corps altered the mitigation plan. The court disagreed, finding NEPA to be satisfied as long as mitigation measures are sufficiently discussed in the EIS to demonstrate agency consideration of the project's adverse impacts. If the EIS sufficiently described the measures and the changes were not substantial, the agency might adopt a modified mitigation plan. . Similarly, the court found that an EIS need not be supplemented even if it is shown that an agency did not consider every possible reasonable alternative. The court noted that the Corps had considered approximately 60 project combinations before selecting the preferred alternative.

With regard to the NHPA claim, the court also ruled in favor of the Corps. Plaintiffs argued that although the Corps had entered into an MOA which provided a mitigation plan, the MOA was no longer valid because the Corps failed to amend the MOA when new data arose. The court examined the Council's regulations and determined that they did not require an MOA to be updated as new information developed and noted that the regulations allowed for but did not mandate amendment of an MOA.

Further, the court observed that while MOAs are strongly encouraged, the regulations do not require their formulation. Because the Corps had conducted multiple archeological studies, consulted with the Council and the SHPO, and entered into a valid MOA to address the project's impact, the court found that the purposes of NHPA had been fulfilled.