Colorado River Information for Utah
Revised: January 2, 2007
Utah is signatory to the Colorado River Compact and the Upper Colorado
River Compact. These compacts basically divide the river so the upper basin states
(New Mexico, Colorado, Utah, and Wyoming)
have an obligation to deliver to the lower basin (Nevada, Arizona, and California) 7.5 million acre feet per
year measured at Lee Ferry (just below Glen Canyon Dam). The Upper Basin
is then entitled to deplete up to the next 7.5 million acre feet from
the Colorado River Basin which is divided
among the states by percentage (Utah's share is 23 percent). After accounting
for reservoir evaporation losses and treaty obligations to Mexico Utah's share
is about 1.4 million acre-feet. The many agreements, laws, and Court Decisions
which constitute the rules for operation on the Colorado River are referred to
as the Law of the River.
Water depletion accounting
is an important component of the Colorado River operation. The
United States Bureau of Reclamation (USBR) operates as a technical resource
to the Secretary of Interior who has oversite over river project operations.
The USBR also maintains
federal project water records which
are helpful to understand operation of the river.
Flaming Gorge and Lake Powell are federal storage projects on the Colorado System
in Utah which were constructed to generate power and to serve both
in state project needs and provide a buffer so the lower basin obligation
can be met. Click the links at the left to review historical storage trends in
the two reservoirs.
Utah is a participant in the
Upper Colorado River Endangered Fish Recovery Program. This partnership
works to recover the endangered species while allowing continued and future
Evaluation of the long term water supply on the Colorado is a topic of
particular interest since the division of the river is based upon assumed
hydrology. Correlation with tree rings is being used to estimate the long
term trends. Information is available on
Lees Ferry streamflow reconstruction.