Chuo Shinkansen Construction Injunction and Damages Lawsuit

In 2021, Shizuoka Prefecture filed a lawsuit against Central Japan Railway Company (JR Central) seeking an injunction to halt construction of the Chuo Shinkansen maglev line's Southern Alps tunnel. The prefecture argued that the environmental impact assessment was inadequate and that the project risked causing serious damage to the Oi River water resources. The Tokyo District Court dismissed the claim in 2023, and the Tokyo High Court upheld the decision in 2024. In 2025, the Supreme Court of Japan rejected the final appeal, ruling that JR Central had taken sufficient environmental measures. The decision ended a major legal hurdle, allowing the controversial high-speed rail project to proceed.

The Supreme Court dismissed the appeal in 2025, finalizing the lower courts' denials of the injunction and permitting construction to continue without further interruption.

Whether JR Central's environmental impact assessment adequately evaluated the risks of the Southern Alps tunnel construction on the Oi River's water flow and ecosystem, and whether an injunction was justified under environmental protection and public interest laws.

The prolonged lawsuit delayed the Chuo Shinkansen timeline and intensified national debate over balancing megaproject development with environmental sustainability. It forced JR Central to implement enhanced water monitoring and mitigation commitments, while the ruling was widely viewed as a judicial precedent favoring critical infrastructure over local environmental objections.