State of Michigan v. U.S. Army Corps of Engineers

Dist. Ct. did not err in denying plaintiffs' request for preliminary injunction in action alleging that defendants' failure to close down parts of Chicago Area Waterway System to avert potential invasion of Asian carp into Lake Michigan constituted public nuisance under federal common law. While Dist. Ct. erred in finding that plaintiffs had shown only minimal chance of succeeding on merits where record showed progression of carp and where plaintiffs would endure substantial likelihood of harm if carp were to gain access to Lake Michigan, denial of request for preliminary injunction was appropriate where defendants showed that balance of harms favored them where costs associated with entry of preliminary injunction were substantial, and where record showed that there was nothing that any preliminary injunction could add, apart from substantial steps already taken by defendants and others to keep Asian carp out of Lake Michigan, that would protect Great Lakes from said invasion while instant lawsuit is being adjudicated.