WaterCalcLabCosts & savings
Practical tools and clear methods for your next water decision.
Rainwater Savings Calculator
Bound potential mains replacement by both available rainwater and eligible demand in the same period.
Open calculator ↗Costs & savingsWater Cost Calculator
Calculate a single volumetric tariff plus a fixed charge in the same billing period.
Open calculator ↗Costs & savingsRainwater ROI Calculator
Estimate simple annual payback using eligible annual demand and actually available annual supply.
Open calculator ↗Costs & savingsAnnual Water Savings Calculator
Calculate annual replacement potential for a specified number of active days. Enter annual usable supply.
Open calculator ↗Costs & savingsWater Usage Comparison Calculator
Compare two measured or modeled volumes for the same period, population and use case.
Open calculator ↗Knowledge & next steps
Costs & savingsCommon Water Waste Problems
Unexpected bills, damp areas, dripping fixtures and irrigation running after shutdown can signal unnecessary consumption. Start with an observation log including time and which equipment was operating. Avoid assuming every damp patch is a pipe leak; rainfall, drainage and other causes can produce similar symptoms. Investigate systematically before choosing a repair.
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Costs & savingsRainwater System Payback Period
Simple payback divides initial investment by annual net cash savings. Net means avoided consumption charges minus relevant recurring costs. Gross roof collection is not an annual cash saving. Estimate water that actually replaces billed use, check the applicable tariff and keep assumptions dated. The calculation is a planning scenario, not a guaranteed investment return.
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Costs & savingsUnderstanding Water Costs
Find billed volume, billing period, volume units, fixed charges and the consumption-dependent tariff. Check whether water and wastewater appear separately. Utilities can use cubic metres, gallons or other billing units. Convert the volume first, then calculate cost. A bill total divided by volume may be an average paid rate, but it is not necessarily the rate avoided by using one less unit.
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Costs & savingsHow to Calculate Water Savings
Decide whether savings mean less utility water, less total water used or lower expenditure. Rainwater substitution can reduce utility demand without reducing total garden use. More efficient irrigation may reduce both. Keep these measures separate so one benefit is not counted twice. Describe the baseline and the proposed change before presenting a percentage.
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Costs & savingsWater Conservation at Home
List regular activities and any fixtures or equipment involved. Record occupancy and separate indoor use from irrigation where possible. Meter readings reveal the whole-home total; event measurements explain where it goes. Focus first on avoidable use that can be changed without compromising necessary hygiene, health or the performance of essential equipment.
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Costs & savingsRainwater Harvesting Costs
Describe connected roof area, usable storage, permitted end uses and the delivery endpoint before requesting quotes. Ask each installer to price the same scope. A barrel-and-hose arrangement and a buried, pumped building system are different projects. A useful budget makes those differences visible rather than combining them into one unsupported international average installation price.
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