No do-overs. When it comes to legal issues, courts call the no do-over rule the doctrine of collateral estoppel, or issue preclusion. It applies when there is an old order on an issue and someone wants a new order on that same issue. To prevent a court from re-visiting a decision on an old order, the opposing party must show all the following conditions: 1) the issues must be identical, and the new issue must have been actually or “necessarily” decided by the old one, 2) the parties must be identical (or nearly so), 3) a final judgment on the old issue, and 4) a full and fair opportunity to have litigated the old issue. This case examines, in the context of a water court order, if an old, but final issue “necessarily” decided the new one. Here, the Court found the old issue could have been decided on grounds different from the new one, so the new issue was not “necessarily” decided.