What is a domestic water improvement district and how does it work in Arizona?

When no city or company will serve a rural area, Arizona lets residents build and own their own water system through a domestic water improvement district (DWID), a local public taxing district that constructs, buys, or runs a water system for an area with no city water line. Arizona authorizes it under A.R.S. Title 48, Chapter 6, the law for county special taxing districts. The way it works is simple. Property owners in an unincorporated area petition the county board of supervisors to form the district. The board holds a hearing and votes. If it passes, the district becomes a small government body. It can charge fees, levy assessments, and even sell bonds to pay for water lines, wells, storage, and delivery. Arizona statute defines it as "a county improvement district that is formed for the purpose of constructing or improving a domestic water delivery system or purchasing an existing domestic water delivery system."

Here is what a DWID is, how one forms, how it pays for water, and the real Rio Verde Foothills case where residents tried to form one.

What a domestic water improvement district is

A DWID is a unit of local government that delivers water where no city or private utility does, and it has real taxing power. It is one type of the broader county improvement district in A.R.S. Title 48, Chapter 6. That law lets counties and their residents build local public infrastructure like sewers, roads, lighting, and water. When the purpose is drinking water, it becomes a domestic water improvement district.

The district is its own public body, separate from the county and from any city. Once formed, it has a board of directors. It can hire a clerk and a superintendent to run the system. The statute spells out these roles. It defines the clerk as "the person appointed by the board of directors to act as the clerk for the district." The board sets the water rates, oversees the system, and answers to the property owners who pay into it.

The key thing to understand is that a DWID is public, local, and funded by the people it serves. It is not a private water company chasing a profit, and it is not the city extending a line. It is the neighbors banding together, using a state-authorized structure, to build and own their own water supply. That power to tax and assess is what lets a small rural community finance a water system it could never buy individually.

How a DWID forms in Arizona

A DWID forms when property owners petition the county board of supervisors. The board then holds a hearing and votes to create the district. The county is the gatekeeper. A.R.S. 48-902 states that "an improvement district may be established in any unincorporated area... by the board of supervisors of the county." Only unincorporated land qualifies, since incorporated cities already have their own water authority.

The process runs in clear steps:

1. Petition. Property owners file a petition with the clerk of the board of supervisors. The petition needs strong owner support. That usually means a majority of the people who own real property in the area, or the owners of 51 percent or more of that real property. The petition names the district, draws its boundaries, and explains how it serves the public.
2. Notice and hearing. The board sets a public hearing and gives notice to affected owners. Owners can object. A property owner can even ask to have their parcel left out, by filing a verified statement before the board adopts the formation resolution.
3. Board vote. The board of supervisors rules on objections and votes on whether to form the district. This is a real vote, not a rubber stamp. The board can say no.
4. Operation. If approved, the district seats a board of directors, sets rates and assessments, and begins building or buying the water system.

The whole structure runs through the county for one reason. Under Arizona law, counties cannot regulate water service on their own. The special taxing district is the legal tool that lets a county-area community finance and govern its own water.

How a DWID pays for water

A DWID pays for its water system through fees, assessments, and bonds, charged to the property owners inside the district. This is the trade for getting public water where none existed: the people served are the people who pay, through their property and their water bills, not through a citywide rate base.

A district raises money three ways. First, it charges water rates for the water customers use, like any utility. Second, it can levy special assessments on the property in the district. Those pay the upfront cost of building lines, wells, and storage. Third, it can issue bonds. The district borrows against future fees to fund big construction now and pays it off over years. That bonding power is what makes a multi-million-dollar water system possible for a small community.

The cost lands on the parcels in the district. That is why owner support matters at formation. A DWID can be the right answer when an area has enough committed owners to share the cost and a real water source to tap. It can be a hard sell when owners disagree about taking on the tax burden. That split is exactly what played out in Rio Verde Foothills.

The Rio Verde Foothills case: a DWID proposed, then passed over

Rio Verde Foothills is the best-known recent Arizona example. It shows that proposing a DWID and forming one are two different things. The City of Scottsdale ended hauled-water access on January 1, 2023. In response, a group of residents proposed forming a domestic water improvement district to take over water delivery. Maricopa County set a vote for August 31, 2022. As the county noted, special taxing districts require board approval, and "state law does not give counties authority to regulate water."

The board of supervisors voted no on the special taxing district. Instead, the county backed a different path. It brought in EPCOR, a private water utility regulated by the Arizona Corporation Commission (ACC), to build and run a permanent standpipe. The state legislature also passed a temporary fix, often called the Standpipe District. It directed Scottsdale to keep supplying water through an intergovernmental agreement until the long-term solution was ready. That stopgap was written to self-repeal on January 1, 2026, the day EPCOR's permanent fill station opened.

So Rio Verde Foothills weighed the DWID route, then took the regulated-utility route instead. The lesson for a buyer is that a "water district" in a rural area can mean very different things. It might be a true DWID the property owners own and tax themselves. It might be a regulated private utility like EPCOR. It might even be a temporary legislative district that has since dissolved. Before you buy a lot, confirm exactly which structure serves it and what it costs. For how this shook out on the ground, see our guide on building in Rio Verde Foothills under the water rules and how to get water to a home in Rio Verde Foothills. For the wider rural checklist, see what you need to build on rural land in Rio Verde. Because water structures and rates change, confirm the current water service and district status for your specific parcel before you close.

Where Jematell Homes comes in

Wells, septic, and hauled-water setups are routine on the rural lots we build. If you are planning a custom home in Scottsdale, Rio Verde, or the greater Phoenix metro, we are happy to walk through your project.

Sources

• A.R.S. 48-902 (Authorization for improvement district; areas and lands excluded)
• A.R.S. 48-1011 (Domestic water and domestic wastewater improvement districts; definitions)
• Arizona Revised Statutes Title 48 (Special Taxing Districts)
• Maricopa County: Board Sets Date to Vote on Rio Verde Foothills Water Issue
• Maricopa County: Advocates for Partnership with Private Water Provider (EPCOR)