San Diego sues Homeland Security and Defense over border concertina wire installed on city-owned conservation land
Lawsuit targets border barrier work in Marron Valley near Otay Mountain
The City of San Diego has filed a federal lawsuit seeking to stop further installation of concertina (razor) wire on city-owned land near the U.S.-Mexico border, alleging federal agencies and military personnel entered the property without authorization and damaged environmentally sensitive habitat.
The complaint, filed Jan. 5 in the U.S. District Court for the Southern District of California, names the Department of Homeland Security and the Department of Defense, as well as senior federal officials, as defendants. The city alleges U.S. Marines and other federal personnel began work in December in Marron Valley, an area east of Otay Mountain, and installed coils of wire and related fencing across open-space terrain.
What the city says was harmed
San Diego’s filing alleges the fencing caused “irreparable harm” to protected habitat, including riparian areas and vernal pools, and that the work interfered with long-standing conservation commitments associated with the property. The city also contends the barrier blocks municipal access needed to monitor and manage the land.
The site is part of the city’s Multiple Species Conservation Program, a regional habitat and open-space network designed to protect 85 covered plant and animal species through designated conservation areas and corridors. San Diego argues that unpermitted construction in these areas can create compliance risks for conservation plans that govern habitat stewardship and mitigation requirements.
Location cited in the complaint: Marron Valley, near the Otay Mountain area of south San Diego County.
Material at issue: concertina wire installed as a barrier reinforcement measure near the border.
Impacts alleged: damage to protected habitat features and interference with access for land management.
Federal response and the city’s requested remedies
San Diego is asking the court to order federal defendants to cease further construction and to recognize the city’s rights to ownership and use of the land. The filing also raises constitutional and property-rights claims tied to alleged unauthorized occupation or use of municipal property.
Public statements from federal agencies have been limited. The Department of Defense has declined to comment on the merits while litigation is pending. The Department of Homeland Security has not publicly detailed a response in court filings as of late January 2026.
Broader context: military support at the border and legal friction
The case lands amid continued federal efforts to reinforce existing border barriers in the San Diego region, including through engineering support missions involving military personnel working in coordination with federal border authorities. The lawsuit sets up a dispute that blends land ownership, environmental compliance obligations, and the scope of federal authority when border infrastructure intersects with locally managed conservation land.
The court will likely be asked early to decide whether emergency limits on further work are warranted while the broader claims proceed.
Next procedural steps may include the federal government’s formal response to the complaint and a hearing schedule on any request for immediate injunctive relief.