Colorado water wells drilled outside of a designated ground water basin were required to be permitted. Colorado law defined a “well” as “any structure or device used for the purpose or with the effect of obtaining ground water for a beneficial use from an aquifer.” In turn, Colorado law defined “beneficial use” as “the use of that amount of water that is reasonable and appropriate under reasonably efficient practices to accomplish without waste the purpose for which the appropriation is lawfully made.” William Vance and others (the ranchers) (plaintiffs) possessed senior riparian water rights on local water subject to the jurisdiction of the Colorado State Engineer and Division Engineer for Water Division 7 (the engineers) (defendants). Oil and gas companies in the region produced coalbed methane (CBM), a process for which water is necessary. The engineers did not require the oil and gas companies to obtain permits for their CBM wells. The ranchers brought suit in the Colorado District Court, Water Division 7, seeking a declaratory judgment that the use of water in the CBM production process was a beneficial use, requiring the CBM wells to be permitted by the engineers. The engineers argued that the use of water during the production of CBM constituted a nuisance, rather than a beneficial use, because the water was an “unwanted byproduct” of the CBM process. The water court granted the ranchers summary judgment, finding that the use of water during the production of CBM was a beneficial use, and that it required a water well permit. The engineers appealed.