absolute water right

A water right, with a specifi priority date, that has been placed to a beneficial use

acre foot

The volume of water required to cover one acre of land to a depth of one foot (43,560 cubic feet or 325,851 gallons).


Adjustments to natural and human systems to moderate harm or exploit beneficial opportunities in response to actual or expected effects of climate change.

adaptive capacity

The ability of systems, organizations, and individuals to (1) adjust to actual or potential adverse changes and events, (2) take advantage of existing and emerging opportunities that support essential functions or relationships, and/or (3) cope with adverse consequences, mitigate damages, and recover from system failures. It is an indicator of how well a system will adjust to and/or recover from external changes or large perturbations (e.g., severe floods or droughts). See also resilience.

Adaptive Management

(AM), also known as adaptive resource management (ARM), is a structured, iterative process of optimal decision making in the face of uncertainty, with an aim to reducing uncertainty over time via system monitoring. In this way, decision making simultaneously maximizes one or more resource objectives and, either passively or actively, accrues information needed to improve future management.


The judicial process through which the existence of a water right is confirmed by court decree.

adverse use

Using decreed water owned by another appropriator.

agricultural applied water use

The applied water use for irrigated agriculture including water applied for groundwater recharge.

agricultural lands stewardship

Conserving natural resources and protecting the environment by compensating owners of private farms and ranches for implementing stewardship practices. Context: Resource Management Strategy.

agricultural water use efficiency

The ratio of applied water to the amount of water required to sustain agricultural productivity. Efficiency is increased through the application of less water to achieve the same beneficial productivity or by achieving more productivity while applying the same amount of water. Context: Scenario Factor, Resource Management Strategy.