Water-loss allocation

Where the gap comes from

A community that buys water through one master meter and then bills residents through individual submeters almost never sees the two numbers match. The master meter always reads higher than the sum of every submeter, because some water is lost along the way: leaks in the distribution piping between the master meter and the units, meter measurement error, flushing, or irrigation on unmetered lines. That difference is the "water loss" a board eventually has to decide how to handle.

Leaks are a bigger contributor than most boards assume. Nationally, household leaks waste an estimated 1 trillion gallons of water a year, an average of more than 9,300 gallons per household, which is a national aggregate, not a prediction for any one property. A simple check can catch a hidden leak before it inflates the next loss figure:

"Check your water meter before and after a two-hour period when no water is being used. If the meter changes at all, you probably have a leak."

Source: Fix a Leak Week, U.S. Environmental Protection Agency, WaterSense program

Why no formula exists

Boards often go looking for the "standard" way to allocate loss, a percentage, a per-square-foot add-on, something defensible. It is not out there. No statute reviewed in Texas, Florida, or California specifies a method for dividing unbilled or lost water among submetered units, so a board should check its own state's submetering statute and public utility commission rules for any required method.

States that do regulate submetering closely regulate adjacent things instead, cost recovery and disclosure, not loss itself. Texas caps what an owner can charge a tenant for submetered water at the utility's actual cost, plus a service charge capped at nine percent, and separately requires that any non-submetered, allocated billing method be disclosed in writing:

"An owner or condominium manager may not impose additional charges on a tenant in excess of the actual charges imposed on the owner."

Source: Texas Water Code 13.5031, Texas Legislature

California's submetering statute is framed around conservation and fairness rather than a billing mechanic. None of these speak to how to divide the gap between what the master meter registers and what every submeter adds up to.

What a defensible policy looks like

Absent a controlling statute, a board's best position is a written methodology, adopted before the charge appears on a bill, not invented after an owner disputes one. Three steps get you there. First, confirm your state has no required method, checking both the submetering statute and any public utility commission rules. Second, have association counsel or your water billing vendor draft the allocation method in writing, and have the board adopt it as policy. Third, apply it consistently to every billing cycle, and keep leak detection active so the gap itself stays small; the two-hour meter test above costs nothing and can be run community-wide.

A board that skips straight to "we'll just split it evenly" is guessing at a rule that, in the states researched, does not exist. A board that documents its reasoning is defending a policy instead.