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Industrial Water Usage Calculator (Litres per Unit and Recycle Rate)

Water is a cost, a permit constraint and a reporting item for many plants, especially in water-stressed regions. This calculator gives a first-pass water balance and intensity so you can find where to look before installing submeters.

Your numbers

m3

Utility meter or well meter reading, municipal and ground water combined.

m3

Sewer meter or discharge permit monitoring.

m3

Reclaimed from rinse, cooling or condensate loops.

units
per m3
per m3

Your results

Recycle rate
25.7%
Share of total water use supplied by reuse.
Litres withdrawn per unit
247.619
Water consumed (m3 per month)
1,300
Water that leaves the site by evaporation or in product, not via discharge.
Monthly water and sewer cost
$26,260
Annual cost
$315,120
Annual cost saved per 10% less withdrawal
$31,512
Assumes discharge falls in proportion to withdrawal.

A true water balance needs metering at each major user. Evaporation, boiler blowdown and water embedded in product are estimated here only by the difference between intake and discharge.

Save results:

Recycle rate vs water recycled

Sweeps Water recycled or reused per month from 0 to 4000, holding your other inputs fixed.

Report water per product from your ERP

Optional: a short conversation about tying utility meters to production quantities.

Optional. The tool and every export work without this. No spam.

How to use it

Enter one typical month. Withdrawal comes from the main meter, discharge from the sewer or permit meter, and recycled water from any reuse loop, such as a rinse recycle or cooling tower blowdown reuse. Add the units produced and your tariffs. The tool returns consumption, recycle rate, litres per unit and annual cost. Run it for different months to see seasonal effects from cooling load.

  • Use readings from the same dates for all meters
  • Include well water as well as municipal supply
  • Enter tariffs including fixed charges averaged per m3
  • Check discharge against permit limits

The method behind it

A water balance says inputs equal outputs plus storage change. Consumption here is withdrawal minus discharge, which captures evaporation, drift and water leaving in product. Recycle rate is reused water divided by total water used, meaning fresh plus recycled. Intensity divides withdrawal by output. Reporting frameworks such as CDP and GRI separate withdrawal, discharge and consumption, and ask for stress-area breakdowns, so keep the three figures distinct.

Reading the result

High consumption relative to withdrawal means evaporative loads such as cooling towers, humidification or open tanks. A low recycle rate with high intensity suggests rinse water or once-through cooling that could be reused. Cost often shows that the sewer charge matters as much as the supply price, so reducing discharge volume can pay back faster than reducing supply alone.

Common mistakes

Common errors are comparing intake bills from different date ranges, missing unmetered uses like fire system tests, treating rain or stormwater as process water, and assuming discharge equals withdrawal. Leaks between meters appear as consumption, so a sudden jump may be a leak rather than a process change. Submeter the largest users to validate the balance.

Frequently Asked Questions

What is the difference between withdrawal and consumption?

Withdrawal is all water taken from a source. Consumption is the part not returned to the source or sewer, lost to evaporation or incorporated into product. Discharge is the part returned. Consumption equals withdrawal minus discharge.

How do I calculate water intensity?

Divide water withdrawn in a period by the output for the same period, for example litres per unit or m3 per tonne. Use a consistent boundary and denominator so trends mean something.

What is a good recycle rate?

It depends on process and regulation. Plating, rinsing and cooling often reach high reuse, while pharma or food lines may be limited. Use trend and comparison with similar sites rather than a single target number.

Why does my discharge exceed withdrawal?

Usually stormwater inflow, unmetered sources such as wells, meter reading date differences or meter error. Review the metering points and read all meters on the same day.

Netray can connect utility meter data with production orders in your ERP so litres per unit is reported by product and line, not just for the whole site.