If you buy acreage in Aguila this fall, the well comes with paperwork. The seller completes the Arizona Association of REALTORS® Domestic Water Well/Water Use Addendum. After closing, the well's registration moves into your name at the Arizona Department of Water Resources. Those documents describe the well as it stands on closing day. They can't describe the aquifer under it, which is the McMullen Valley basin. That basin is at the center of a statewide water dispute, and two decisions may come before spring: a likely return of groundwater-export legislation when lawmakers convene in 2027, and a local special election on March 9, 2027.
For an Aguila buyer, the house, barn and acreage are easy to evaluate. The well is what decides the property's value over the long term.
The Two Pages That Come With the Well
The AAR addendum goes with any property served by a well. It asks the seller to answer questions about:
- Whether the well is registered to the seller, plus the registration number
- Whether the well is shared among households, and whether any well agreement is in effect or recorded
- Where the well and any storage tanks are located
- Whether the property is inside an Active Management Area
- Any known water-quality tests and flow-test results
- Any past problems with inadequate production or equipment
- Other water sources serving the property
- Whether a Statement of Claimant is on file
The form also includes a notice telling the buyer to investigate the water-use laws and water-right issues that apply to the property.
On the state side, ADWR requires the registered owner to notify the department when ownership changes, and the new owner supplies information to keep the registration current. The filing is Form 55-71A. It can be submitted on paper or through ADWR's online change-of-ownership application. It carries a $30 fee and asks for proof of land ownership and an assessor parcel map marked with the well's location.
The addendum's "AMA status" question has a simple answer in Aguila today, since the McMullen Valley basin is not an Active Management Area. The rest of this post explains why that answer could change during an escrow that opens this winter.
How Deep the Water Sits Around Aguila
The most detailed published survey of the basin's water levels is ADWR's hydrologic monitoring report, released in September 2020. It reflects measurements from water year 2017, so treat it as a historical baseline rather than current readings.
| Area of McMullen Valley | Depth to water, WY2017 | Water-level change, WY2005 to WY2017 |
|---|---|---|
| Around Aguila | Over 500 feet, two wells over 700 feet | Declines of 4 to 37 feet |
| Between Aguila and Wenden, along Centennial Wash | 249 to 570 feet | Declines of 5 to 27 feet |
| Around Salome and Wenden | 107.6 to 616.4 feet | Declines of 38 to 82 feet |
Aguila's water was the deepest in the valley in that survey, but its decline over those twelve years was smaller than at the western end of the basin. As a result, a well near Aguila typically starts deep and costs more to drill, while the water level under it had been falling more slowly than it was near Salome and Wenden. ADWR also measured a basin-wide median change of 19.2 feet across 78 well pairs, at a median rate of about 1.6 feet per year.
The cost of going deeper shows up in Wenden. The Arizona Mirror reported in March 2026 that the Wenden Domestic Water Improvement District spent $1.3 million drilling its wells to 1,500 feet. One resident's household well was 250 feet deep and a neighbor's was 600 feet. Those are Wenden figures, not quotes for an Aguila parcel. They do show the range of costs between a household well and community-scale drilling in the same aquifer.
Why This Basin Draws Interest From Outside the Valley
The McMullen Valley basin covers about 720 square miles in La Paz, Maricopa and Yavapai counties. It includes Wenden, Salome and Aguila, and about 3,000 people live there. Most of the water use is not residential. ADWR's November 2023 basin assessment attributed 99% of demand to agriculture. It found that from 1990 to 2022, an average of three acre-feet left the basin for every acre-foot supplied, and in 2022 that ratio reached five to one. The same report said further depletion could require well owners to deepen or replace wells at significant cost.
The basin's legal status adds another layer. Since 1991, McMullen Valley has been one of Arizona's "transportation basins," a designation that allows groundwater to be moved from it into an Active Management Area. In practice, that means the Phoenix area. Phoenix once owned a 12,000-acre farm in the basin and sold it in 2012.
In 2024, Emporia III, a subsidiary of New York-based Water Asset Management, bought about 13,000 acres of McMullen Valley farmland for $100 million. As the law stands, those owners can't sell the groundwater to Valley customers. House Bill 2758 would have changed that. Reports differ on how much water the bill would have allowed. KTAR described a cap of up to 33,000 acre-feet a year. The Arizona Mirror calculated roughly 78,000 acre-feet a year from a limit of six acre-feet per acre across 13,000 acres. The bill also included a 1,200-foot pumping-depth limit and a cap on basin-wide decline averaging 10 feet per year over 100 years.
Compare that 1,200-foot limit with the depths in the table above. A household well that reaches water at 500 or 700 feet around Aguila would sit well above the floor that bill set for export pumping.
The Dates a Buyer Closing This Winter Will Own Through
Here is the sequence so far:
- February 19, 2026. HB 2758 passed the Arizona House 32 to 24.
- Spring 2026. The bill did not pass the Senate. KTAR reported in September that residents expect the measure to return next session.
- August 2026. Residents launched the McMullen Valley Water Defenders PAC to petition for a special election on forming a local Active Management Area. The petition needs signatures from 10% of the valley's registered voters, and the group set a goal of 200. Only valley residents, including those in Aguila, Salome, Wenden and Harcuvar, can sign and vote.
- October 1, 2026. The Arizona Capitol Times reported that signature collection was still underway and the PAC chair expected the measure to qualify. That report did not mention any filing or an official call for the election.
- March 9, 2027. This is the target date for the special election, which falls in the middle of the next legislative session.
The two efforts don't cancel each other out. Sarah Porter, director of ASU's Kyl Center for Water Policy, told KJZZ that creating an AMA would not change McMullen Valley's status as a transportation basin. KTAR quoted the PAC's view that an AMA would not stop export efforts but would slow them significantly. Either outcome, or both, could arrive within months of closing on a property bought today.
What an AMA Looks Like One Basin Over
The neighboring Ranegras Plain basin shows what AMA rules look like in rural western Arizona. ADWR Director Tom Buschatzke designated it the state's eighth AMA on January 9, 2026. ADWR said withdrawals there had exceeded natural recharge by roughly 900%, and that one well had dropped more than 240 feet since the 1980s.
Under the Ranegras designation, most high-capacity non-exempt wells must now measure and report how much groundwater they pump. New irrigated acreage is generally limited to land irrigated in the five years before a November 5, 2025 baseline, with an exception for substantial capital investment. Those rules target large irrigation wells, which matches McMullen Valley's own demand picture, where agriculture accounts for nearly all use. Ranegras is a separate basin, and any McMullen AMA would be shaped by its own process, so this is an illustration of how the rules work rather than a forecast for Aguila.
Reading an Aguila Parcel With All of This in Mind
The addendum questions carry more weight once you know the basin's background. A recent flow test and a record of past production give you a starting point for the specific well on the property. A recorded shared-well agreement tells you how water would be divided among households if output declined. If the addendum lists other water sources, such as storage tanks or hauling arrangements, it shows what the property relied on before. The registration number confirms the well is on file with ADWR, so the 55-71A transfer can proceed after closing.
The basin-level numbers describe the aquifer that every one of those wells draws from. Around Aguila, that means deep water, a slower recorded decline than at the western end of the valley, and a policy calendar that will be active through March 2027.
A Few Questions I Hear Often
Is Aguila in an Active Management Area right now? No. As of October 2026, the McMullen Valley basin is not an AMA. A special election on forming one is targeted for March 9, 2027, if the petition qualifies.
Did the Ranegras Plain AMA change anything for Aguila wells? The January 2026 designation applies to the Ranegras Plain basin, which is separate from the McMullen Valley basin where Aguila sits.
Who handles the well registration transfer? ADWR's rules call for the registered owner to report the ownership change and for the new owner to keep the registration current, using Form 55-71A and a $30 fee.
Are the Wenden well depths typical for Aguila? No. They come from the western end of the basin. ADWR's most recent published survey placed depth to water around Aguila at more than 500 feet in 2017.
If you're looking at acreage or horse property around Aguila and want to go through a well addendum, a flow test or the 2027 water calendar before you commit, Connie Jenson is glad to go over it with you. Let's Connect.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
