Water Reuse Savings Calculator

Work out water reuse savings instantly with clear inputs, formula shown and shareable results.

About Water Reuse Savings Calculator

Water reuse saves the cost of fresh water and often the cost of discharging effluent, less the cost of treating it to the required standard. The net saving per cubic metre is the difference between fresh water cost and reuse treatment cost — reuse only pays where that gap is positive and the reuse demand is genuine.

Formula

Reuse saving

Net saving = volume reused x (fresh water cost - reuse treatment cost)

Worked example

With the default values below, Water Reuse Savings Calculator returns Annual Net Saving of $5,775,000.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Wastewater Availableminimum 0 m3/day: 500 m3/day
Fraction Suitable For Reuseaccepts 0–100 %: 60 %
Fresh Water Costminimum 0 per m3: 85 per m3
Reuse Treatment Costminimum 0 per m3: 30 per m3

Results

Annual Net Saving: $5,775,000.0
Net Daily Saving: $16,500.00
Volume Reused: 300.00
Net Saving Per Cubic Metre: $55.000

Step by step

1Values used
2Reuse saving
3Annual Net Saving= 5,775,000.0
4Net Daily Saving= 16,500.00
5Volume Reused= 300.00
6Net Saving Per Cubic Metre= 55.000

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Water reuse for any application involving human contact is subject to microbiological and chemical quality standards. Confirm the applicable reuse regulations and validation requirements.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Water reuse for any application involving human contact is subject to microbiological and chemical quality standards. Confirm the applicable reuse regulations and validation requirements.

Frequently Asked Questions

What are the common reuse applications?

Cooling tower make-up, boiler feed after further polishing, process washing, irrigation, toilet flushing and dust suppression. Each has a different quality requirement and therefore a different treatment cost.

Should avoided discharge cost be included?

Yes where effluent is charged volumetrically or where discharge capacity is constrained. It often turns a marginal reuse case into a clearly positive one.