Introduction

In Harrison County v. U.S. Army Corps of Engineers, the Fifth Circuit affirmed the dismissal of a challenge by several Mississippi local governments and industry groups seeking to compel the U.S. Army Corps of Engineers (the Corps) to obtain incidental take authorization under the Marine Mammal Protection Act (MMPA) before opening the Bonnet Carré Spillway. The spillway diverts Mississippi River floodwaters into Lake Pontchartrain, ultimately affecting salinity in the Mississippi Sound. The appellants alleged that past openings in 2011 and 2019 coincided with “unusual mortality events” for bottlenose dolphins and caused economic, recreational, and aesthetic harms across the region.

The district court dismissed the suit under Rule 12(b)(1) for lack of Article III standing, and the Fifth Circuit (per curiam, unpublished) affirmed. The court held the plaintiffs failed to show an injury that is “certainly impending” and thus lacked the imminent injury necessary to obtain prospective or declaratory relief. The decision underscores a concrete application of the Supreme Court’s imminence requirement in environmental cases that target episodic federal operations contingent on variable natural conditions.

Parties:

• Plaintiffs–Appellants: Harrison County, Mississippi; Cities of Biloxi, D’Iberville, and Pass Christian; Mississippi Hotel and Lodging Association; Mississippi Commercial Fisheries United, Inc. (collectively, “Harrison County”).
• Defendant–Appellee: U.S. Army Corps of Engineers.

Core issue: Whether plaintiffs had Article III standing to prospectively compel the Corps, via the Administrative Procedure Act (APA), to seek an MMPA incidental take authorization before any future opening of the Bonnet Carré Spillway.

Summary of the Opinion

The Fifth Circuit affirmed the district court’s dismissal for lack of standing, concluding that Harrison County did not demonstrate a concrete, imminent injury sufficient for prospective relief. The court emphasized:

• Past harm (e.g., dolphin mortality in 2011 and 2019) is insufficient by itself to show a “real and immediate threat” of future harm.
• The Spillway’s operation is contingent on unpredictable flood conditions, and no future opening was scheduled or forecasted at the time of filing.
• Not all Spillway openings cause the alleged harms (e.g., openings in 2016, 2018, and 2020 did not yield the same injuries asserted for 2011 and 2019), introducing another layer of uncertainty.

Citing City of Los Angeles v. Lyons, the court held that plaintiffs failed to show a “certainly impending” future injury. Distinguishing Crawford v. Hinds County, it noted that unlike the recurring, near-inevitable jury summons in a small county, future spillway-related injuries depend on numerous variables and are episodic. Because injury in fact was lacking, the court did not reach causation or redressability (though it noted the overlap between these elements in footnote 3). The panel also left unresolved the underlying APA theory, including whether the MMPA imposes any legally required, discrete duty for the Corps to seek incidental take authorization.

Analysis

Precedents Cited and How They Shaped the Decision

• Spokeo, Inc. v. Robins, 578 U.S. 330 (2016) and Lujan v. Defenders of Wildlife, 504 U.S. 555 (1992): The court invoked these cases for the fundamentals of injury in fact—requiring an invasion of a legally protected interest that is concrete and particularized. Spokeo reinforces that concreteness and particularization are distinct requirements; Lujan anchors Article III limits on federal judicial power in concrete adverseness.
• TransUnion LLC v. Ramirez, 594 U.S. 413 (2021): Emphasized that plaintiffs must have a personal stake; mere statutory violations or abstract risks are insufficient. It frames the standing inquiry’s rigor, especially for forward-looking relief.
• Friends of the Earth, Inc. v. Laidlaw Environmental Services, 528 U.S. 167 (2000): Cited for the three elements of standing—injury in fact, causation, and redressability—and the necessity of concrete harm, not just procedural grievances.
• Clapper v. Amnesty International USA, 568 U.S. 398 (2013): Central to the opinion’s “certainly impending” standard. The Fifth Circuit leaned heavily on Clapper to reject speculative future injuries built on chains of contingencies. Here, the contingencies included flood-stage thresholds, rainfall, runoff, Corps’ operational choices (whether, when, how long to open), and whether an opening would actually cause dolphin harm.
• City of Los Angeles v. Lyons, 461 U.S. 95 (1983): The key analog. Lyons held that prior harm from a chokehold did not establish a real and immediate threat of future harm; by analogy, past harmful spillway openings (2011 and 2019) did not establish that another harmful opening is imminent. The Fifth Circuit applied Lyons to reject prospective injunctive relief premised on episodic, non-scheduled, and contingent future events.
• Crawford v. Hinds County Board of Supervisors, 1 F.4th 371 (5th Cir. 2021): Distinguished. Crawford involved a wheelchair user repeatedly called to jury duty at an inaccessible courthouse. The Fifth Circuit characterized that injury as likely to recur based on a single variable (future summons) within a small population. By contrast, spillway operations implicate many variables and only sometimes result in the alleged harms, making future injury not “certainly impending.” The court also drew on Crawford’s “systemic vs. episodic” distinction: plaintiffs here alleged episodic harms from some—but not all—openings.
• James v. Hegar, 86 F.4th 1076 (5th Cir. 2023): Reiterated that for prospective relief, plaintiffs must show continuing harm or a real and immediate threat of repeated injury; mere possibility is not enough.
• FDA v. Alliance for Hippocratic Medicine, 602 U.S. 367 (2024): Cited for the insight that causation and redressability often operate as flip sides of the same coin. While the court did not reach these elements, it flagged their interplay with the imminence analysis.
• Book People, Inc. v. Wong, 91 F.4th 318 (5th Cir. 2024) and Simon v. Eastern Kentucky Welfare Rights Organization, 426 U.S. 26 (1976): Included to clarify causation need not be the sole cause (Wong) and to reiterate the necessity of likely redressability (Simon). Again, not dispositive here because injury in fact failed.
• Grupo Dataflux v. Atlas Global Group, 541 U.S. 567 (2004): Standing is measured at the time the action is brought—important because plaintiffs could not rely on later forecasts or generalized climate trends that did not concretize a scheduled or imminent opening as of filing.
• FW/PBS, Inc. v. City of Dallas, 493 U.S. 215 (1990); Steel Co. v. Citizens for a Better Environment, 523 U.S. 83 (1998): Reinforced that plaintiffs bear the burden to affirmatively allege standing and that courts must ensure jurisdiction exists before reaching the merits.
• Crane v. Johnson, 783 F.3d 244 (5th Cir. 2015); Barilla v. City of Houston, 13 F.4th 427 (5th Cir. 2021): Set out the standard of review and allowed consideration of materials outside the pleadings to test jurisdiction, which mattered because evidence suggested some openings did not harm dolphins and one declarant had successful dolphin cruises even in a year with an opening (2020).
• Norton v. Southern Utah Wilderness Alliance, 542 U.S. 55 (2004): Cited in a footnote to flag that an APA claim must seek to compel a discrete agency action that is legally required. The court did not reach this issue because standing failed, but its inclusion signals a substantial merits obstacle even if standing had been established.

Legal Reasoning

The plaintiffs sought declaratory and injunctive relief to compel the Corps to obtain an MMPA incidental take authorization before any future opening of the Spillway. To obtain such prospective relief, they had to show an imminent injury—a “certainly impending” threat—not merely a speculative or possible future harm.

The court’s reasoning proceeded in three steps:

1. Imminence of a future opening was not shown. The Spillway opens only when the Mississippi River reaches flood-stage thresholds determined by dynamic, unpredictable conditions (rainfall, runoff, surges). No opening was scheduled or forecasted at the time of filing. Thus, the prospect of a future opening, while possible, was not “certainly impending.”
2. Even if an opening were imminent, imminence of injury was not shown. Not all openings allegedly caused dolphin harms. Plaintiffs themselves highlighted 2011 and 2019 as injury-causing, yet the Spillway was also opened in 2016, 2018, and 2020. Evidence suggested 2020 did not depress dolphins in a way that produced the same injuries (a declarant operating dolphin cruises reported success). Therefore, beyond the occurrence of an opening, an additional (uncertain) causal step is necessary: that the opening would produce the injuries asserted. This layered uncertainty defeated imminence.
3. Past injury does not establish a real and immediate threat of future injury. Relying on Lyons and Clapper, the court held that past harm—even serious environmental harm—does not suffice to justify forward-looking relief absent a non-speculative likelihood of recurrence. Distinguishing Crawford, the court emphasized the multi-variable, episodic nature of spillway operations, contrasting them with the quasi-automatic recurrence of jury summons in a small county. The panel also analogized plaintiffs’ claim to “one-off, episodic” conduct, not a “systemic” policy that invariably causes injury when triggered.

Because the plaintiffs failed to carry their burden on injury in fact, the court did not analyze causation or redressability in full. In a footnote, it observed that the question of whether all openings lead to plaintiffs’ injuries bears on both imminence (injury in fact) and traceability (causation), but resolved the appeal solely on the first element. Likewise, the court did not reach the contested merits issues: whether the MMPA imposes a duty to apply for incidental take authorization and whether the APA would permit a court to compel such an application under Norton’s “legally required, discrete” action standard.

Impact

Although unpublished and thus non-precedential under 5th Cir. R. 47.5, this decision meaningfully signals how the Fifth Circuit analyzes imminence in environmental cases seeking forward-looking relief against episodic, contingency-driven federal operations:

• High bar for imminence in episodic environmental operations. Plaintiffs aiming to compel federal agencies to obtain incidental take authorization (or impose other preconditions) will struggle to show “certainly impending” injury where operations turn on natural variables and management discretion, unless a particular operation is scheduled or concretely forecasted at the time of filing.
• Past ecological events and climate trends, standing alone, are insufficient. The court treated references to climate-driven increases in rainfall or high river discharge as too general to establish an imminent, discrete injury from this agency’s operation. Future filings may need contemporaneous operational forecasts or formal agency notices to ground imminence.
• Episodic vs. systemic framing matters. The court embraced Crawford’s distinction: to secure prospective relief, targeting a systemic and consistently injurious practice is easier than targeting episodic conduct that only sometimes causes harm. Environmental plaintiffs may consider framing claims to systemic policies (e.g., water control manuals, operating criteria) rather than to single-event operations, particularly when the policy allegedly guarantees a risk of harm each time it is applied.
• APA pathway remains uncertain and demanding. Even if plaintiffs can establish standing, compelling an agency to seek an MMPA authorization via the APA would require identifying a discrete action that is legally required (Norton). The panel flagged but did not decide this hurdle. Parties should anticipate briefing on whether MMPA’s framework “authorizes” versus “requires” applications for incidental takes, and whether any duty can be enforced under §706(1).
• Strategic timing is critical. Standing is assessed at filing (Grupo Dataflux). Plaintiffs contemplating prospective relief should calibrate suits to coincide with specific, impending operations (e.g., announced or imminent openings) to satisfy Clapper’s “certainly impending” standard.
• Limited immediate operational effect on the Corps or NMFS. Because the court did not reach causation, redressability, or the merits of MMPA/APA interaction, the ruling leaves intact the Corps’ existing practice of not seeking MMPA incidental take authorization for spillway openings and does not bind NMFS to alter its incidental take regulations.

Complex Concepts Simplified

• Article III Standing: The constitutional requirement that plaintiffs show (1) a concrete and particularized injury that is actual or imminent; (2) the injury is fairly traceable to the defendant; and (3) a favorable court decision would likely redress the injury. For forward-looking relief (injunction/declaration), the injury must be a real and immediate threat of repeated harm—not just a fear of something that might happen.
• “Certainly Impending” Injury: A high standard from Clapper: courts reject suits based on speculative future events that depend on a chain of contingencies. Plaintiffs must show the threatened injury is genuinely on the verge of occurring.
• Lyons Analogy: Having suffered a past wrong (e.g., an improper chokehold or a harmful spillway opening) does not prove you are likely to face that wrong again. Prospective relief demands evidence that the same harm is poised to recur.
• Marine Mammal Protection Act (MMPA) Incidental Take Authorization: The MMPA generally prohibits “taking” marine mammals (harassing, hunting, capturing, killing). It allows a process for authorizing incidental takes associated with specific activities over up to five years if the impact is “negligible” and subject to mitigation and monitoring. The process typically involves a petition to NMFS, notice-and-comment, regulations, and a Letter of Authorization (LOA). The Act does not provide a private right of action to enforce its prohibitions; enforcement is by the federal government, which is why plaintiffs often resort to the APA.
• APA §706(1) Claims (Norton v. SUWA): The APA allows courts to compel agency action “unlawfully withheld or unreasonably delayed,” but only if the action is both discrete and legally required. If a statute merely authorizes (rather than mandates) agency action, §706(1) typically cannot be used to compel it.
• Unpublished Opinions (5th Cir. R. 47.5): Unpublished decisions in the Fifth Circuit are not binding precedent except in limited circumstances. They nonetheless illuminate how the court approaches similar issues and may be persuasive.
• Bonnet Carré Spillway Mechanics: The Spillway mitigates flood risk when the Mississippi River approaches levels that threaten levees. Opening it is not routine or scheduled; it depends on dynamic hydrologic modeling and forecasts. Its discharge can lower salinity in downstream ecosystems, potentially affecting species like bottlenose dolphins, but impacts vary with environmental conditions and the manner/duration of operations.

Conclusion

Harrison County clarifies an exacting requirement for environmental plaintiffs seeking prospective relief against episodic, contingency-dependent government operations: absent a scheduled or forecasted action that is “certainly impending,” and absent evidence that such action will imminently cause the asserted injury, Article III standing fails. Past harms and generalized predictions (even plausibly linked to climate trends) do not satisfy the imminence threshold where multiple natural and managerial variables intervene.

By analogizing to Lyons and relying on Clapper’s imminence standard, the Fifth Circuit underscores that plaintiffs cannot leverage historical environmental injuries to obtain forward-looking injunctions unless they can concretize a future injury at the time of filing. The opinion also hints at unresolved merits questions (especially under Norton v. SUWA) about whether the MMPA creates any discrete, legally required duty to seek incidental take authorization that a court could compel via the APA. While unpublished, the decision signals to litigants that timing, evidentiary specificity, and the systemic-versus-episodic framing will be decisive in future Fifth Circuit environmental standing disputes involving flood-control operations and marine mammal protections.