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Western Plateau Planning Area Population

The Western Plateau Planning Area is the most sparsely populated planning area in the state although there are some rapidly growing areas.  Census data for 2000 show almost 17,500 residents in the planning area.  Arizona Department of Economic Security (DES) population projections suggest that the planning area population will more than double by 2030, to about 35,000 residents.  Historic, current and projected basin population is shown in the cultural water demand tables for each basin in sections 6.1-6.6.

The 2000 Census populations for each basin and Indian reservation, from highest to lowest, are listed in Table 6.0-4. The most populous basin is the Coconino Plateau with about 9,200 residents in 2000.  The Shivwits Plateau and Grand Wash basins have very low populations with 12 and 15 residents in 2000, respectively. 

Table 6.0-4  2000 Census Population in the Western Plateau Planning Area

Table 6.0-4

Table 6.0-5 lists  incorporated and unincorporated communities in the planning area with 2000 Census populations greater than 500 and growth rates for two time periods.  Communities are listed from highest to lowest population in 2000.  The planning area population grew by 35% between 1990 and 2000.  There are only three incorporated communities in the planning area, Colorado City, Fredonia and Williams.  Relatively rapid growth has occurred in several areas including Beaver Dam/Littlefield, Colorado City, Valle and Cameron.  The unincorporated areas of Beaver Dam/Littlefield and nearby Scenic, Arizona, are experiencing growth in large part due to their proximity to growth in Mesquite, Nevada. Mesquite experienced an annual growth rate of almost 12% between 2000 and 2008 (Hardcastle, 2008), fueled by development of retirement communities and its growing popularity as a resort destination.

Table 6.0-5 Communities in the Western Plateau Planning Area with a 2000 Census population greater than 500

Table 6.0-5

Population Growth and Water Use

Arizona has limited mechanisms to address the connections between land use, population growth and water supply.  A legislative attempt to link growth and water management planning is the Growing Smarter Plus Act of 2000 (Act) which requires that counties with a population greater than 125,000 (2000 Census) include planning for water resources in their comprehensive plans.  Of the two counties in the planning area, only Mohave County fit the size criteria in 2000.  The Mohave County water resources element will develop a water budget for each of the groundwater basins in the county and will prioritize this effort based on growth potential, water availability, number of wells and other factors (Freilich, Leitner & Carlisle, 2005). However, the County’s key water issues and planning efforts are related primarily to that part of the County south of the Colorado River. Although not required by law to include a water resources element in the county’s comprehensive plan, Coconino County has done so. The County Plan emphasizes conservation in tandem with resource development and recognizes the importance of incorporating climatic variability into water resource planning (Coconino County, 2003).

The Act also requires that twenty-three communities outside AMAs include a water resources element in their general plans.  In the Western Plateau Planning Area this requirement applies only to Colorado City.  Plans must consider water demand and water resource availability in conjunction with growth, land use and infrastructure.

Beginning in 2007, all community water systems in the state were required to submit Annual Water Use Reports and System Water Plans to the Department. The reports and plans are intended to reduce community water systems’ vulnerability to drought, and to promote water resource planning to ensure that water providers are prepared to respond to water shortage conditions.  In addition, the information will allow the State to provide regional planning assistance to help communities prepare for, mitigate and respond to drought. 

An Annual Water Use Report must be submitted each year by the systems that includes information on water pumped, diverted, and received, water delivered to customers and effluent used or received. The System Water Plan must be updated and submitted every five years and consist of three components, a Water Supply Plan, a Drought Preparedness Plan and a Water Conservation Plan.  By January 1, 2008 all systems were required to submit plans.  By the end of 2008, plans had been submitted by 18 systems including City of Williams, Colorado City, Fredonia, Grand Canyon National Park and HydroResources-Tusayan and were used to prepare this document.  Annual water report information and a list of water plans are found in Appendix B.

Williams Main Stree

Main Street Williams.  Beginning in 2007, all community water systems in the state were required to submit Annual Water Use Reports and System Water Plans to the Department.

The Department’s Water Adequacy Program also relates water supply and demand to growth to some extent, but does not control growth.  Developers of subdivisions outside of AMAs are required to obtain a determination of whether there is sufficient water of adequate quality available for 100 years.  If the supply is inadequate, lots may still be sold, but the condition of the water supply must be disclosed in promotional materials and in sales documents.  Legislation adopted in June 2007 (SB 1575) authorizes a county board of supervisors to adopt a provision, by unanimous vote, which requires a new subdivision to have an adequate water supply in order for the subdivision to be approved by the platting authority.  If adopted, cities and towns within the county may not approve a subdivision unless it has an adequate water supply.  If the county does not adopt the provision, the legislation allows a city or town to adopt a local adequacy ordinance that requires a demonstration of adequacy before the final plat can be approved.  As of September 2009, no counties or towns in the planning area have adopted this provision.

Subdivision adequacy determinations (Water Adequacy Reports), including the reason for the inadequate determination, are provided in basin tables and maps and are summarized in Table 6.0-6.  As shown, 86 subdivisions with over 5,400 lots were reviewed for an adequacy determination through 2008. All subdivisions were found to have an inadequate water supply in the Coconino Plateau Basin while all subdivisions were found to have an adequate supply in the Paria Basin.

Table 6.0-6 Water adequacy determinations in the Western Plateau Planning Area as of 12/2008

Table 6.0-6

Shown in the basin sections are approved applications for an Analysis of Adequate Water Supply (AAWS). This application is typically associated with large, master planned communities. The only AAWS determinations in the planning area are in the Virgin River Basin where two applications totaling 27,700 lots have been approved.

No water providers in the planning area are designated as having an adequate water supply for their entire service area as of the date of publication of this document.  However, an application for a designation of adequate water supply was pending for Beaver Dam Water Company as of September 2009. A service area designation exempts subdivisions from demonstrating water adequacy if served by the provider.


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