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Population of the Southeastern Arizona Planning Area

Census data for 2000 show about 188,300 residents in the Southeastern Arizona Planning Area.  Arizona Department of Economic Security (DES) population projections forecast about 294,600 residents by 2030.  Historic, current and projected basin populations are shown in the cultural water demand tables for each basin in Sections 3.1-3.14. Projections may not accurately reflect the most recent proposed developments.

The most populous basins reported in the 2000 census are the Upper San Pedro (78,013), Safford (42,281), Douglas (26,220), Lower San Pedro (15,515), and Willcox (12,354) basins.  Six basins in the planning area are sparsely populated, with less than 200 residents including Aravaipa Canyon, Bonita Creek, Donnelly Wash, Dripping Springs Wash, San Bernardino Valley and San Rafael basins.  The 2000 Census population of the San Carlos Apache Reservation was 9,385, an increase of over 2,000 residents since the 1990 census.  The 2000 Census populations for each basin and Indian reservation, listed from highest to lowest, are shown in Table 3.0-4.

Table 3.0-4 2000 Census Population of the Southeastern Arizona Planning Area and Indian Reservations

Basin/Reservation 2000 Census Population
Upper San Pedro
San Carlos Apache 8,270
Lower San Pedro
Cienega Creek
Duncan Valley
Dripping Springs Wash
Donnelly Wash
San Rafael
Aravaipa Canyon
San Bernardino Valley
Bonita Creek
San Carlos Apache

Table 3.0-5 Communities with a Census population greater than

1,000 (listed by 2000 population)

Communities Basin 1990 Census Pop. 2000 Census Pop. Percent Change 1990-2000 2006 Pop. Estimate* Percent Change 2000-2006 Projected 2030 Pop.
Sierra Vista USP 32,983 37,775 14.5 44,870 18.8% 67,264
Sierra Vista SE USP 9,237 14,348 55.3 16,551 15.4% 23,398
Douglas DOU 13,137 14,312 8.9 17,660 23.4% 28,685
Safford SAF 7,359 9,232 25.5 9,835 6.5% 9,953
Bisbee USP/DOU 6,288 6,090 -3.1 6,355 4.4% 8,483
Benson USP 3,824 4,711 23.2 4,820 2.3% 4,856
San Manuel LSP 4,009 4,375 9.1 NA -- 5,102
Thatcher SAF 3,763 4,022 6.9 4,970 23.6% 6,994
Willcox WIL 3,122 3,733 19.6 3,910 4.7% 4,491
San Carlos SAF 2,918 3,716 2.7 4,918 32.4% 6,074
Oracle** LSP 3,043 3,563 17.1 NA -- NA
Clifton MOR 2,840 2,596 -8.6 2,485 -4.3% 2,526
Whetstone USP 1,289 2,354 82.6 2,810 19.4% 4,228
Kearny LSP 2,262 2,249 -0.6 2,270 0.9% 3,740
Swift Trail Jct. SAF 1,203 2,195 82.5 2,558 16.5% 3,878
Pima SAF 1,725 1,989 15.3 2,080 4.6% 2,529
Morenci MOR 1,799 1,879 4.4 1,821 -3.1% 1,828
Huachuca City USP 1,782 1,751 -1.7 1,825 4.2% 2,145
Mammoth LSP 1,845 1,762 -4.5 1,805 2.4% 2,228
St. David USP 1,468 1,744 18.8 1,862 6.8% 2,229
Tombstone USP 1,220 1,504 23.3 1,655 10.0% 2,032
Dudleyville LSP 1,356 1,323 -2.4 NA -- 2,769
Peridot SAF 957 1,266 32.3 NA -- NA
Total >1,000   109,429 128,489 17.4 NA -- 195,431
Remainder of Planning Area   46,236 59,793 29.3 NA -- 99,197
Total    155,665 188,282 20.9 NA -- 294,628
Sources: ADOC 2006, U.S. Census 2006
* 2006 population shown is the 2006 estimate for incorporated areas and the 2006 projection for unincorporated areas.
** The community of Oracle is located in the Lower San Pedro Basin but its water supply comes from wells at Oracle Junction in the Tucson AMA.
USP = Upper San Pedro, DOU = Douglas Basin, SAF =  Safford Basin, WIL =  Willcox Basin, LSP =  Lower San Pedro Basin MOR = Morenci Basin

Shown in Table 3.0-5 are incorporated and unincorporated communities in the planning area with 2000 Census populations greater than 1,000 and growth rates for two time periods. Communities are listed from highest to lowest population in 2000. As shown, there are several rapidly growing communities including Sierra Vista and adjacent areas, Douglas, Whetstone and Swift Trail Junction south of Safford. The largest municipality in the planning area is Sierra Vista with a 2000 Census population of 37,775, or 20% of the planning area population. The population of the Sierra Vista subwatershed (roughly the southern half of the basin), contained about 37% of the planning area population in 2000. Approximately half the population of the San Carlos Apache Reservation resides in the communities of Peridot and San Carlos (the 10th largest community in the planning area and the tribal headquarters). Some communities in the planning area, including Clifton, Kearny and Mammoth have lost population due to declines or closures of mining operations. Between 1990 and 2000, the population living in smaller communities and rural areas grew faster than the population living in communities with 1,000 or more residents.

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.  None of the counties in the planning area fit this population criterion.  However, Cochise County has incorporated water resource planning into its comprehensive plan, has adopted water use guidelines for certain area plans and has adopted a Water Conservation and Management Policy Plan for the Sierra Vista sub-watershed portion of the basin.

Its goal is to “sustain an adequate, safe water supply through water conservation measures; policies; incentive programs; education; conservation and enhancement of natural recharge areas; and cooperative, multi-jurisdictional planning”.  The Act also requires that twenty-three communities outside AMAs include a water resources element in their general plans.  In the Southeastern Arizona Planning Area this includes the communities of Benson, Douglas, Safford and Sierra Vista. Plans must consider water demand and water resource availability in conjunction with growth, land use and infrastructure. References to completed plans are listed in basin references in this volume.

Beginning in 2007, all community water systems in the state were required to submit Annual Water Use Reports and System Water Plans. 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 and by the end of 2008, plans were submitted by 61 community water systems in the planning area.  Almost all of the larger systems submitted plans and were used to prepare this document. Annual water report information and a list of water plans are found in Appendix B.  For more information see the Department's community systems water webpage.


Sierra Vista

City of Sierra Vista including Fort Huachuca, in the

Upper San Pedro Basin.  Sierra vista is the largest municipality in the planning area.  The Sierra Vista Subwatershed contained about 37% of the planning

area population in 2000.

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.  The Cochise County Board of Supervisors was the first in the state to adopt the provisions of SB 1575 in March, 2008. The Town of Patagonia, located in Santa Cruz County, has also adopted the provision since Santa Cruz County has not adopted the new standards.

Table 3.0-6 Summary of Water Adequacy Determinations in the Southeastern Arizona Planning Area through December 2008

Basin Number of Subdivisions Number of Lots* Adequate Inadequate Approx. Percent Inadequate
Aravaipa Canyon none none none none none
Bonita Creek none none none none none
Cienega Creek 13 >1,023 867 >156 15%
Donnelly Wash 1 59 0 59 100%
Douglas 8 433 83 350 81%
Dripping Springs Wash none none none none none
Duncan Valley 3 >268 61 >207 77%
Lower San Pedro 12 >1,211 1,195 >16 1%
Morenci 11 >1,859 >1,825 34 2%
Safford 23 >905 139 >766 85%
San Bernardino Valley none none none none none
San Rafael none none none none none
Upper San Pedro 202 >24,923 >18,218 >6,705 27%
Willcox 20 >1577 989 >588 37%
TOTAL 293 >32,258 >23,377 >8,881 28%


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 3.0-6.  Also 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. As of December, 2008, AAWS applications had been approved in three basins for a total of 10,357 lots: Cienega Creek Basin, 189; Lower San Pedro Basin, 2,948; and Upper San Pedro Basin, 7,220.  (See tables 3.3-11, 3.8-11 and 3.13-11)

Six water providers in the planning area are designated as having an adequate water supply for their entire service area.   A service area designation exempts subdivisions from demonstrating water adequacy if served by the provider. Designation information and the general location of the service area are also shown in basin maps and tables. As of December, 2008, designated providers included:

  • City of Benson
  • City of Douglas
  • City of Safford
  • City of Willcox
  • Empirita Water Company – West of Benson, Cienega Creek Basin
  • Bachmann Springs Utility Company – Bachman Springs Development near Tombstone


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