Can my Arizona landlord bill me for water with a submeter or RUBS?

Yes. The Arizona Residential Landlord and Tenant Act, found in A.R.S. Title 33, Chapter 10, lets a landlord pass utility costs through to tenants. Section 33-1314.01 is the part that covers water, sewer, and other utilities billed by submeter or by a ratio formula. It sets the conditions a landlord must meet to charge you this way.

The first condition is disclosure. The lease or rental agreement has to tell you that water is billed back to you, and which method is used. If the lease says nothing about a separate water charge, a landlord generally cannot start sending you one out of the blue. For an existing tenant, a change to a billing method usually requires written notice well in advance, often a 90-day notice before the new charge starts.

The second condition is no profit. The landlord may bill you only for the actual cost of the water and sewer service, plus a reasonable, actual administrative or service fee that the statute allows. The landlord is not permitted to mark up the utility and turn your bill into a hidden source of income. The administrative fee is meant to cover the real cost of reading meters, doing the math, and sending statements, not to pad the rent.

The third condition is transparency. On request, the landlord must be able to show you the master utility bill and the usage data behind your charge. If you ask how a number was reached and the landlord cannot or will not back it up with the source bill, that is a red flag worth raising.

These rules apply whether you rent a single house, a duplex, or an apartment in a large complex. The method can differ from building to building, and some properties bill water as a flat monthly add-on instead of by use, which is a separate arrangement that still has to be spelled out in the lease. The common thread is that the charge must be written into your agreement, tied to the real cost, and backed by records you can inspect. A water charge that fails any one of those tests is worth questioning before you pay it.

The two methods sound similar but work in opposite ways, and the difference matters for your bill.

A submeter is a real water meter installed on the line feeding your individual unit. It measures the exact gallons that flow into your apartment. Your bill reflects your own use, the same way the city meter measures the whole building. If you cut back on showers and laundry, your submetered bill goes down. Submeters used for billing are treated as measuring devices, so they fall under Arizona Corporation Commission utility rules and state weights and measures oversight for accuracy.

RUBS is not a meter at all. With a Ratio Utility Billing System, the building has one master meter, and the landlord takes that single bill and allocates it across units using a formula. Common formulas use the number of occupants, the unit square footage, the number of bedrooms, or a blend. Because RUBS is an estimate, your share is tied to the formula, not to a meter on your door. A careful, low-water household in a building of heavy users can still pay an allocated share that feels high, since the math spreads the total rather than measuring you.

In plain terms: a submeter charges you for what you actually used, and RUBS charges you for an assigned slice of what everyone used. Neither is automatically unfair, but they answer your "why is it this much?" question very differently.

Landlords often choose RUBS because retrofitting an older building with individual submeters is expensive, and a master meter is already in place. That is legal in Arizona, but it shifts the fairness question onto the formula. If your building uses occupant-based RUBS, the count of people in each unit matters, so ask how the landlord verifies occupancy and how vacant units are handled. A formula that ignores empty apartments can quietly raise the share charged to the units that are occupied.

Before you pay or dispute a water charge, work through a short checklist. It turns a vague worry into specific questions a landlord has to answer.

• Lease disclosure. Find the clause that authorizes the water charge and names the method, submeter or RUBS. No clause usually means no valid charge.
• The method. Is there a real submeter on your unit, or is this a RUBS allocation? Ask which one in writing.
• The calculation. For a submeter, ask for your start and end reads. For RUBS, ask for the exact formula, the master bill total, and how your share was figured.
• The fees. Confirm any administrative or service fee is itemized and reasonable. Watch for a markup above the real utility cost, which the statute does not allow.
• The master bill. Ask to see the underlying city water and sewer bill. The landlord should provide it on request so you can check that the pass-through matches the real cost.

Keep copies of your statements and your written requests. A clear paper trail is the strongest tool you have if a charge looks wrong, and it is exactly what a housing counselor or attorney will ask for first.

Yes, and this is where plumbing and billing meet. A hidden leak can push a water bill far above normal, and the effect depends on the billing method.

With a submeter, a leak inside your own unit, such as a running toilet or a dripping water heater, shows up directly as higher metered use, so your bill climbs. A running toilet alone can waste a large volume of water every day. If your submetered bill jumps with no change in your habits, run a simple meter leak test and look for a silent leak. See our guides on a high water bill with no visible leak and how to do a water meter leak test.

With RUBS, the leak does not even have to be in your unit. A leak on the master-metered system, in a common area, an irrigation line, or another apartment, raises the building's total bill. Since RUBS splits that total, your allocated share goes up even though you used the same water. If every unit's RUBS bill spikes at once, a building leak is a prime suspect, and tenants can ask the landlord to find and fix it. Who pays for the repair itself depends on where the leak is and what the lease says, which ties into who is responsible for water line repairs.

For a building-wide spike, a landlord can have a plumber pressure-test the system and locate the leak before another billing cycle passes the cost on to tenants.

The rules above come from state statute, but landlord-tenant questions are fact-specific, and the details of your lease and your city's utility setup can change the answer. Use the primary sources, then get tailored advice if money is on the line.

Read A.R.S. 33-1314.01 yourself on the Arizona Legislature site, since it spells out the disclosure, no-profit, and access-to-records rules in the state's own words. The Arizona Department of Housing publishes plain-language material on the Residential Landlord and Tenant Act. For submeter accuracy questions, the Arizona Corporation Commission oversees utility submetering rules under the Arizona Administrative Code.

The statute itself ties the charge to real cost. A.R.S. 33-1314.01 directs that a landlord billing utilities this way charge for service in a way tied to the actual provider rates, and the Act bars turning the utility pass-through into profit. If your numbers do not line up with the master bill, that is the standard to point to.

If a charge still looks wrong after you have checked the lease and the math, talk to a landlord-tenant attorney or a local legal-aid or housing-counseling office before you withhold payment. Withholding rent on your own can put your tenancy at risk, so confirm your position against the statute and your specific lease first. This page is general information, not legal advice, and your situation may turn on facts only an attorney who reviews your lease can weigh.