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

> Source: https://netray.co/tools/water-usage-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Build a simple plant water balance: consumption, intensity per unit, recycle rate and the yearly cost of water and sewer charges.

## Category

ehs-workforce

## Industry

Manufacturing

## Audience

- EHS manager
- Utilities engineer
- Sustainability lead

## Tool

**Kind:** calculator

**Inputs:**

#### Fresh water withdrawal per month

**Key:** withdrawal

**Type:** number

**Default:** 5200

**Min:** 0

**Step:** 100

**Unit:** m3

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

#### Wastewater discharged per month

**Key:** discharge

**Type:** number

**Default:** 3900

**Min:** 0

**Step:** 100

**Unit:** m3

**Help:** Sewer meter or discharge permit monitoring.

#### Water recycled or reused per month

**Key:** recycled

**Type:** number

**Default:** 1800

**Min:** 0

**Step:** 100

**Unit:** m3

**Help:** Reclaimed from rinse, cooling or condensate loops.

#### Units produced per month

**Key:** units

**Type:** number

**Default:** 21000

**Min:** 1

**Step:** 500

**Unit:** units

#### Water price

**Key:** water_price

**Type:** number

**Default:** 3.1

**Min:** 0

**Step:** 0.1

**Unit:** per m3

#### Sewer and discharge charge

**Key:** sewer_price

**Type:** number

**Default:** 2.6

**Min:** 0

**Step:** 0.1

**Unit:** per m3

**Outputs:**

#### Water consumed (m3 per month)

**Key:** consumption

**Expr:** max(withdrawal - discharge, 0)

**Format:** integer

**Description:** Water that leaves the site by evaporation or in product, not via discharge.

#### Recycle rate

**Key:** recycle_rate

**Expr:** if(gt(withdrawal + recycled,0), recycled / (withdrawal + recycled) * 100, 0)

**Format:** percent

**Primary:** true

**Description:** Share of total water use supplied by reuse.

#### Litres withdrawn per unit

**Key:** l_per_unit

**Expr:** withdrawal * 1000 / units

**Format:** decimal

**Primary:** true

#### Monthly water and sewer cost

**Key:** monthly_cost

**Expr:** withdrawal * water_price + discharge * sewer_price

**Format:** currency

#### Annual cost

**Key:** annual_cost

**Expr:** monthly_cost * 12

**Format:** currency

#### Annual cost saved per 10% less withdrawal

**Key:** annual_saving_10

**Expr:** annual_cost * 0.1

**Format:** currency

**Description:** Assumes discharge falls in proportion to withdrawal.

**Chart:**

#### Recycle rate vs water recycled

**Type:** line

**X:** recycled

**From:** 0

**To:** 4000

**Steps:** 24

**Series:**

- recycle_rate

**Disclaimer:** 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.

## Content

**Intro:** 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.

**Sections:**

#### How to use it

**Body:** 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.

**Bullets:**

- 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

**Body:** 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

**Body:** 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

**Body:** 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.

**Cta:** 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.

**Faq:**

#### What is the difference between withdrawal and consumption?

**Answer:** 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?

**Answer:** 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?

**Answer:** 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?

**Answer:** 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.

## Search terms

water usage calculator, industrial water consumption calculator, water intensity per unit, plant water balance template, water recycling rate calculator, factory water footprint, water cost savings calculator, m3 per tonne water intensity

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