The Metropolitan Water District of Southern California can add the costs of transporting water via the State Water Project to what it bills its customers, but it cannot tack on so-called “water stewardship” charges, the California 1st District Court of Appeal says in a ruling Wednesday. Metropolitan says the ruling vindicates its position. But on the other side of the watery divide is the San Diego County Water Authority, which also says it won the day at the appellate court. The central issue in dispute is one of cost allocation