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Central Arizona Project Holds Workshop on Firming, Wheeling and Exchanges

On February 1st, the Central Arizona Project held a workshop on Firming, Wheeling and Exchanges on CAP facilities.  With the prospect of shortages on the Colorado River looming, the Central Arizona Project faces the risk of cutbacks of 320,000 AF in available annual Colorado River supplies.  The workshop reported on extensive recent stakeholder efforts to resolve long-standing issues regarding the use of CAP facilities for firming, wheeling and exchanges.

The presentation provides an excellent summary of the historical context of the issues and proposed actions.  First, key definitions:

  • Firming: “the use of one supply to increase the reliability of another supply” (primarily through the recovery of stored water during shortages)
  • Wheeling: transporting project or non-project water on CAP facilities with unused capacity
  • Exchanges: swapping of one water supply for another, such as Colorado River water for effluent or Colorado River water for groundwater in conjunctive use programs.

A draft CAP System Use Agreement between the Central Arizona Water Conservation District (“CAWCD”) and the United States would set the framework for firming, wheeling and exchanges.  The Agreement would authorize CAWCD to deliver recovery exchange water, replenishment exchange water and non-project water for firming, on-river firming and interstate agreements.  Other non-project water deliveries would require a federal or CAWCD wheeling agreement.  The Agreement would include an approved standard form wheeling agreement.

The proposal would use the CAWCD Annual Operating Plan to determine scheduling priorities for the use of CAP facilities.  It would set a uniform 5% loss factor for non-project water (exempting firming water). Once the initial annual delivery requests of CAP water users are received, the availability and timing of unused capacity would be determined.  Wheeling requests would be met in accordance with the following priorities (firming water carries the scheduling priority of the supply it replaces):

  1. Long-term contracts delivered directly or by exchange for use within the contractor’s service area or reservation, or leases, exchanges and underground storage within the same segment or an upstream segment
  2. The agricultural settlement pool through 2030
  3. CAWCD Wheeling Contracts after project completion and verification
  4. Long-term contracts delivered for leases, exchanges and underground storage in downstream segments
  5. Other excess water
  6. Federal wheeling for Indian and federal agency purposes
  7. Federal wheeling for other purposes
  8. CAWCD Wheeling Contracts before system improvement and project completion

The proposal would require that any water put into the CAP system met standards set by the CAWCD and the Bureau of Reclamation.  It would also allow the CAWCD to impose fees, charges and revenues to recoup its costs for developing firming supply and retain improvement fees for capacity expansion projects, subject to Reclamation oversight.

Changes in water resource practices are often driven by the need to address challenges.  With shortages on the Colorado River looming, the time may be ripe for the resolution of wheeling and exchange issues dating back to the 1980s.  If current efforts culminate in a CAP firming, wheeling and exchange policy, it will provide the needed framework for Arizona to better manage its water resources in times of shortage.  A successful venture in Arizona may provide a template for how other federal water projects can address their issues over wheeling and exchanges.

CAWCD expects to release a draft CAP System Use Agreement by the end of the year.


Written by Rodney T. Smith, Ph.D.