The majority of the money utilized by the AWBA comes from existing revenue sources and from fees paid by those that benefit directly from the stored water. There are restrictions on the manner in which funds must be expended based on their source of generation. The AWBA obtains its funding from three sources:
- Fees for groundwater pumping collected within the Phoenix, Pinal and Tucson Active Management Areas (AMA). In the Phoenix AMA, Tucson AMA and most areas of the Pinal AMA, fees are charged at $2.50 per acre foot. Credits accrued with these monies must be used to benefit the AMA in which they were collected.
- A four cent ad valorem property tax in the three county CAP service area. The CAWCD is statutorily authorized to levy this tax through 2016. If the money is not needed for certain CAP costs, the funds are deposited into a District fund and are used to defray the AWBA's costs associated with the purchase of CAP water. It has done so every year since the AWBA’s inception. Money from this source must be used to benefit the county in which it was collected.
- A general fund appropriation in an annual amount determined to be appropriate by the Arizona Legislature and the Governor. Funding from this source has not been available. Water stored with these funds may be used to assist communities along the Colorado River, to assist in meeting state water management objectives or as a component of Indian water rights settlements.
In addition to the three general funding sources, an additional $8 million for intrastate storage was made available from the Southern Nevada Water Authority (SNWA) pursuant to the Arizona-Nevada Shortage Sharing Agreement. This fund, referred to as the Shortage Reparation Fund, is intended to assist Arizona in storing water to offset impacts from Colorado River shortages that may occur during the Interim Period (2008 through 2026).
In 2005, the AWBA received funding to meet the terms of the Amended Agreement for Interstate Water Banking. The initial $100 million received in 2005 is intended to be an “insurance” payment to develop alternative water resources for Nevada if needed. To pay for the cost of water delivery and storage, Nevada was originally scheduled to make ten payments of $23 million each beginning in 2009 through 2018 .
Pursuant to the Letter Agreement dated December 8, 2010, the payment schedule was modified to resume in 2014 and end in 2024.
In the future, additional sources will likely include fees collected from the replacement of general fund credits used for drought protection and fees associated with water banking services agreements.
Through December 2012, the AWBA is expected to have expended over $300 million in the process of developing an estimated 3.8million acre-feet of long-term storage credits. The 2013 Plan of Operation is currently being developed.