Efficiency in Western Water Law: The Development of the California Doctrine, 1850–1911

The development of water law in California has been heavily studied by legal historians. Much interest and controversy has surrounded the fact that early on, California adopted a system of water law that recognizes both riparian and appropriative rights and that persists to this day. How well this hybrid system has promoted economic efficiency in the use of water in California has been poorly understood. This article examines the early development of California water law to understand how such a hybrid system emerged and how well it promoted economic growth. The key argument is that nineteenth‐century California jurists, though constrained by legislative mandates to observe English common law, worked within the confines of that doctrine to mitigate some of its potential inefficiencies. This article provides empirical evidence that those jurists selectively promoted appropriative claims in situations of high transactions costs in order to encourage reallocation of water from existing riparian uses.