ABSTRACT
Variety is found in the water law doctrines that have developed in the Western states. The doctrine of prior appropriation is the prevailing doctrine everywhere, but it is modified or constrained in a variety of ways. Diversity is also encountered in the institutional structures for development and management of water. These structures range from private and mutual water companies, to public entities that themselves take a variety of forms. The varied physical circumstances in which water is found and applied affects public policy and the extent to which various policy approaches may achieve conservation goals. The character of the groups that are engaged in irrigation agriculture also affects water policy, constraining options and revealing possibilities. Both diversity and complexity are found in existing and potential political and financial arrangements. The general discussion of the concepts of conservation and efficiency provides a necessary backdrop for a more detailed examination of these concepts as they apply to irrigation agriculture.
