On March 30, 2026, the U.S. District Court for the Northern District of California issued a decision in Center for Biological Diversity v. U.S. Department of the Interior, No. 24-cv-04651, vacating four federal regulations governing how the U.S. Fish and Wildlife Service (“FWS”) and the National Marine Fisheries Service (“NMFS,” together the “Services”) conduct interagency consultations under Section 7 of the Endangered Species Act (“ESA”). The pre-2019 versions of those regulations are now in effect until the Services issue replacements.
The decision has immediate and practical consequences for any project requiring a federal permit, license or other federal action that may affect a listed species or its critical habitat — including infrastructure, energy, transportation, water resources and large-scale development projects.
What the court vacated
The Court invalidated four provisions added in the 2019 rulemaking and largely retained in the 2024 rulemaking:
- The “reasonably certain to occur” standard in the definition of “effects of the action” (50 C.F.R. § 402.02). The Court held that this standard was more demanding than the statute’s “likely” threshold and improperly excluded relevant scientific evidence from the consultation analysis.
- The treatment of non-binding mitigation measures under 50 C.F.R. § 402.14(g)(8). The Court held that the Services cannot satisfy their duty to “insure” against jeopardy by relying on mitigation that is not legally binding or otherwise guaranteed.
- The “as a whole” qualifier in the definition of “destruction or adverse modification” (50 C.F.R. § 402.02). The Court held that this language permitted piecemeal degradation of critical habitat in a manner inconsistent with the statute.
- The removal of the Services’ duty to request reinitiation of consultation under 50 C.F.R. § 402.16(a). The Court held that the Services failed to adequately justify eliminating a regulatory duty that had been in place for more than 25 years.
The Court upheld two challenged Section 4 regulations concerning the “foreseeable future” standard for threatened species listings and the conditions under which concurrent critical habitat designation may be deemed not prudent.
What this means for clients
Project proponents currently in formal consultation should anticipate delays. The Services are pausing pending biological opinions while internal guidance is developed for applying the reinstated pre-2019 framework. Mitigation-dependent projects warrant particular attention: measures previously credited as proposed but non-binding may now require firm, enforceable commitments — through permit conditions, project descriptions, or other binding mechanisms — to count in the jeopardy analysis.
Clients with recently issued biological opinions should consider whether those opinions were materially based on the vacated provisions, particularly the mitigation-measure rule, and assess potential vulnerability to challenge.
Clients planning future federal actions with ESA implications should expect a period of regulatory uncertainty extending through 2026 and likely beyond.
What’s next
The Services are expected to appeal the ruling to the U.S. Court of Appeals for the Ninth Circuit. Separately, in November 2025, the Services published proposed rules that would re-adopt much of the 2019 framework; final rules are anticipated by late 2026 and will likely face their own legal challenges. The interaction between the appeal, the pending rulemaking, and any future litigation will shape ESA compliance obligations for the foreseeable future.
This is an evolving situation. We will continue to monitor and provide updates as developments warrant.
Last updated: May 8, 2026
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Smith Hulsey & Busey advises clients on federal environmental permitting, ESA compliance, and related regulatory matters. If you have questions about how this ruling may affect a current or planned project, please contact John Wallace at jwallace@smithhulsey.com .
This publication intends to offer readers information on current topics of general interest. It is important to note that this publication does not establish, suggest, or formalize the existence of an attorney-client relationship. The content herein should not be regarded as legal advice or opinion, as it may not be applicable to the specific circumstances of a particular situation. Given the continual evolution of guidance in various areas, it is advisable to periodically monitor for updates and seek legal counsel prior to making any decisions.
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