Board of Water Works Trustees of the City of Des Moines, Iowa v. Sac County Board of Supervisors, as Trustee of Drainage Districts 32, 42, 65, 79, 81, 83, 86, and Calhoun County Board of Supervisors and Sac County Board of Supervisors as Joint Trustees of Drainage Districts 2 and 51 and Buena Vista County Board of Supervisors and Sac County Board of Supervisors as Joint Trustees of Drainage Districts 19

WATERMAN, Justice.

This high-profile litigation pits one political subdivision of the State of Iowa against several other political subdivisions. The plaintiff is a municipal waterworks; the defendants are upstream drainage districts and their trustees. The plaintiff provides drinking water to central Iowans and is suing for money damages and other remedies to recover its costs to remove nitrates from Raccoon River water. The case was brought in federal court. Our role is simply to answer the following questions of Iowa law certified by that court.

Question 1: As a matter of Iowa law, does the…