Water Planning for Growing Southwestern Communities - Design with the Desert: Conservation and Sustainable Development - page 269

TABLE 15.1
Colorado River Allocations

Annual Allocation (Million
Acre-Feet per Year) State

Upper basin
Colorado

3.88 MAFY

Utah 1.73 MAFY

Wyoming 1.05 MAFY

New Mexico 0.85 MAFY

Lower basin
Nevada

0.30 MAFY

Arizona 2.85 MAFY

California 4.40 MAFY

Mexico 1.50 MAFY

Total 16.5 MAFY

stewardship at the home, but is aware that water saved at one household may enable the
next home to be built. 4
While the connection of population growth to water availability is obvious, there is often
a significant disconnect between land-use planning and water planning. Different agen-
cies and individuals split or share responsibilities, as in Arizona where water regulations
are handed down from the state level for municipalities to implement alongside local
comprehensive land-use plans. There is an intermingling of the private and public sector
in water provision. As communities in the Southwest find themselves growing into their
known water supplies or finding out that certain water supplies cannot be counted on as
reliably as previously thought, water planning has taken on a more visible and important
function. This essay considers key issues related to planning water supply portfolios and
water management strategies for growing Southwestern cities.

15.2 Traditional and Nontraditional Water Supplies
As discussed elsewhere in this volume, traditional sources of water have been groundwater
and surface water, the latter often diverted for delivery through human-made systems (see
Chapters 4, 21, and 26). Groundwater and surface water are connected, as any student of
the hydrologic cycle knows, but they are often managed as separate systems. Water quality
regulations are often established and enforced by different agencies than those that oversee
water quantity (water supplies), although water quantity and quality are obviously connected
as well. The quality of water is a key determinant of the water available for use. Seawater
had not been considered a water supply available for community use until the technology
to remove salt became economically feasible. The outflow of wastewater treatment plants—
called effluent —had been considered a nuisance or something to be disposed of rather than
a valuable water resource. Like desalinated seawater or brackish water, effluent treated to
high standards is now considered an important water resource. 5 Arizona laws consider
discharged effluent to be appropriable as surface water.* In New Mexico, state and regional

* 1989 John F. Long water rights case.