Judge Sue Robinson's ruling late Wednesday upheld the Corps' claim that its federal duty to maintain waterway navigation can override individual state powers.
Robinson said Delaware failed to act in a reasonable time frame on the plan to deepen the channel between Philadelphia and the Delaware Bay, but she barred the Corps from deepening in other sections of the project, pending a new Delaware permit review.
Supporters say dredging will keep local ports competitive. But opponents say it will stir up toxic sediments.
Pennsylvania has supported the idea, but New Jersey joined Delaware in suing the Corps.
