Bill comparison / Establish the baseline
Start with consumption, not the dollar total
Use consistent volume unitsAverage daily water use = billed water volume ÷ billing days
A larger bill can reflect more water, a longer billing period, or changes in rates, sewer charges, and fees. Locate the consumption figure, its unit, and the number of billed days. Divide volume by days to compare average daily use; keep units consistent rather than comparing gallons with a different billing unit.
Compare with both the previous period and the same season last year when available. Note guests, new planting, pool filling, or controller changes. A higher daily average is a reason to investigate, not proof of a leak. If consumption is similar but charges rose, ask your utility to explain the account and bill.
Usage monitoring: Phoenix Water’s high-bill guidance.
Separate indoor, pool, and irrigation water use
Check for a running toilet, dripping fixtures, appliance cycles, and a water softener regenerating unexpectedly. A pool autofill can replace evaporation, but an unusual fill pattern may need a pool professional’s assessment. These uses can affect the same property meter as irrigation. Do not assume an outdoor-looking increase belongs to the sprinklers.
Outside, note damp ground, runoff, displaced drip tubing, or heads operating beyond their scheduled time. Record when each symptom occurs: all day, after a cycle, or only while one zone runs. That timing helps the appropriate professional narrow the source without treating a meter reading as a diagnosis.
Household and irrigation checks: EPA WaterSense: Start Saving.