Unused Colorado River Apportionment
Under the current Law of the River, lower basin states (Arizona, California and Nevada) are allowed to use the unused apportionment of another state.
For example, if Arizona does not use its full allocation of 2.8 million acre-feet, Nevada and California are allowed the unused portion. None of the Water Authority planning charts includes the other lower basin states' unused apportionments, but SNWA will use this resource if it is available.