BuildMeter guide · Water & Mechanical
Water Leak and Pump Energy Cost Guide
Convert hidden water loss and pumping runtime into annual operating cost. Includes measurement workflow, a worked example, decision table, ordering checkpoints, common failures and professional boundaries.
Direct answer
What to know first
Convert hidden water loss and pumping runtime into annual operating cost.
Open Water Leak Cost CalculatorA leak can cost both water and pumping energy
For homes using a well or booster pump, a continuous leak has two operating costs: the water itself where water is metered, and the electricity used to move that water. The two calculations need different inputs. Leak volume comes from flow × time; pump electricity comes from motor input power × runtime.
| Cost | Needed inputs | Calculation |
|---|---|---|
| Lost water | Leak flow and duration | Flow × time |
| Water bill | Lost volume and tariff | Volume × water/sewer rate |
| Pump runtime | Lost volume and delivered pump flow | Volume ÷ flow |
| Electricity | Pump input kW and runtime | kW × hours |
Worked leak example
A 0.25 gpm leak wastes 360 gallons per day (0.25 × 60 × 24). Over 30 days that is 10,800 gallons. If a well pump delivers 10 gpm while running, supplying the leaked water requires about 36 pump-hours during the month. At 1.1 kW input, that is about 39.6 kWh. At $0.18/kWh, pump electricity alone costs about $7.13, before any water/sewer charge or added pump wear.
Use the calculators
- Measure or estimate leak flow with the Water Leak Cost Calculator.
- Convert lost volume into pump runtime using the actual delivered pump flow, not the motor nameplate alone.
- Use the Water Pump Energy Cost Calculator with measured or rated input power.
- For cycling concerns, review pressure-tank drawdown and pump controls separately.
Common mistakes
- Confusing gallons per hour with gallons per minute.
- Using pump horsepower as electrical kW without accounting for motor/input efficiency.
- Assuming pump flow is constant regardless of pressure/head.
- Ignoring sewer charges that may be billed from metered water consumption.
Professional limits
Unexpected pump cycling can indicate leaks, pressure-tank issues, check-valve problems or other faults. Persistent cycling and water-system problems should be diagnosed rather than treated only as an energy-cost calculation.