Central Highlands Planning Area Water Supply - Central Arizona Project Water

Water supplies in the Central Highlands Planning Area include surface water, groundwater and effluent.  Central Arizona Project (CAP) water diverted from the Colorado River via the CAP canal is stored in the planning area but is not utilized within it.  Surface water from local streams is used extensively for agricultural irrigation in the Verde River Basin and to some extent in the Salt River Basin where it is also diverted to meet mining demand, primarily outside of the planning area.  It is estimated that about 36% of the total water demand in the planning area is met with surface water.  Groundwater is the primary water supply in the planning area, accounting for about 63% of the demand.  Effluent is utilized for golf course irrigation in the Tonto Creek and Verde River basins, contributing 1% of the planning area’s water supply. (see Figure 5.0-15)

For purposes of the Atlas, water diverted from a watercourse or spring is considered surface water and if it is pumped from wells it is accounted for as groundwater.  This is reflected in the cultural water demand tables in each basin section. 

Central Arizona Project Water

New Waddell Dam, located on the Agua Fria River in the Phoenix Active Management Area, stores CAP water in Lake Pleasant located in the Agua Fria Basin.  This water is not a direct supply for the planning area.  The dam also stores Agua Fria River water and provides flood control.  In the winter, water is pumped from the CAP canal to Lake Pleasant.  When demand increases in the summer, water is released through the same canal to downstream CAP contractors within the Central Arizona Water Conservation District (CAWCD) service area; Maricopa, Pima and Pinal counties.

Six municipal and industrial water providers or water users and three Indian Tribes in the planning area were allocated an entitlement of CAP water (Table 5.0-7).  In order to physically acquire water under their respective subcontracts, it was anticipated that subcontractors located outside of the CAP service area would exchange their CAP entitlement for a locally available surface water supply that was held by a downstream senior water right holder located within the CAP service area. The CAP entitlements held by Indian Tribes could also be included in any future, potential water settlement.

Due to environmental issues associated with the potential exchange of its CAP entitlement for East Verde River water rights held by SRP, the town of Payson chose to sell its CAP entitlement to the City of Scottsdale.  The transfer process was completed in 1994.  The money acquired from the sale was deposited into a trust fund managed by the U.S. Bureau of Reclamation for the purpose of developing alternative water supplies for Payson.

Table 5.0-7 CAP subcontractors and transferred entitlements in the Central
Highlands Planning Area*

*Does not reflect the reduction associated with equivalency charges and capital costs due to CAWCD or other fees associated with the entitlement transfer actions.

In response to the proposed transfer of Payson’s CAP subcontract to Scottsdale, the Department developed a transfer policy to govern the transfer of a CAP entitlement from a subcontractor located outside of the CAP service area.  Subsequent to the adoption of this policy, Camp Verde Water System, Inc., Cottonwood Water Works, Inc. and the Mayer Domestic Water Improvement District decided to transfer their subcontracts to Scottsdale.  Monies resulting from the sale of these entitlements were also placed in separate trust fund accounts for each entity.  Table 5.0-7 lists the entitlement volumes that were eventually transferred to Scottsdale and the gross proceeds that resulted from the respective transactions.

In accordance with each trust fund agreement, the Department provides oversight regarding expenditures from these accounts to ensure that trust fund monies are used to defray expenses associated with “designing, constructing, acquiring and/or developing an alternative water supply in an amount which may include, but is not limited to, a combined net increase” in the subcontractor’s “water system capacity to replace the CAP allocation” that it sold.

Plans regarding the CAP entitlements held by Phelps Dodge Miami, Inc. and Pine Water Company are not known.  The San Carlos Apache Tribe leases a portion of its CAP allocation to the City of Scottsdale and as exchange water for use by Freeport McMoRan at Morenci in the Southeastern Arizona Planning Area.  The Tonto-Apache and the Yavapai-Apache tribes have no current uses or exchanges.

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