In many states where water is in relatively short supply, statutes have passed authorizing a system of prior appropriation in which owners downstream do not necessarily have to wait for what's left after those upstream have drawn their fill. Priority–who gets to appropriate water first–is instead established by date of approved filing and continued conformity with any rules and limitations on use imposed by the jurisdiction. What is this system called?
1) Doctrine of Prior Appropriation
2) Doctrine of Riparian Rights
3) Doctrine of Absolute Ownership
4) Doctrine of Reasonable Use