Loss balance calculators
Build a water balance (IWA layout, with the Infrastructure Leakage Index) or an energy balance (with a feeder table) from your own figures. The calculators organise your numbers and show what is left unexplained. They do not find losses.
WATER: VOLUMES (m3 per year)
From your system input and billing data
Illustrative placeholder. Replace with your own figure.
Illustrative placeholder. Replace with your own figure.
Illustrative placeholder. Replace with your own figure.
For example utility own use that is metered.
For example flushing and firefighting, estimated.
WATER: APPARENT LOSS ASSUMPTIONS
Your estimates, not measured values
Your estimate. Starting value is an illustrative assumption.
Your estimate from meter tests, if you have them.
Your estimate from billing audits, if you have them.
WATER: NETWORK DATA FOR ILI
Needed to work out unavoidable annual real losses
Property boundary to customer meter.
WATER: VALUING THE VOLUMES
Optional. Enter your own unit values.
Usually the marginal production cost. Leave at 0 to hide values.
Usually the retail tariff. Leave at 0 to hide values.
WATER BALANCE
| Component | m3 per year | Share of system input | Value (EUR) |
|---|
Layout follows the IWA/AWWA standard water balance. ILI = current annual real losses divided by unavoidable annual real losses (UARL). UARL = (18 x Lm + 0.8 x Nc + 25 x Lp) x P litres per day, with Lm = mains length in km, Nc = number of service connections, Lp = total private pipe length in km between property boundary and customer meter, and P = average operating pressure in metres (Lambert et al., IWA Water Loss Task Force). The formula is intended for systems with more than about 5,000 connections, more than 20 connections per km of mains and pressure above 25 m; outside that range treat the ILI with caution. Reference bands are shown for orientation only. Confirm the method and the bands with a water-loss engineer before relying on them.
ENERGY: NETWORK TOTALS (kWh per year)
From input metering and billing data
Illustrative placeholder. Replace with your own figure.
Illustrative placeholder. Replace with your own figure.
For example network own use and unmetered public lighting.
ENERGY: ASSUMPTIONS AND VALUES
Your estimates. Optional values in EUR.
Your estimate, for example from an engineering study. Starting value is illustrative.
Usually the cost of supply. Leave at 0 to hide values.
Needed for AT&C. Leave at 0 to skip.
Needed for AT&C. Leave at 0 to skip.
ENERGY BALANCE
| Component | kWh per year | Share of energy input | Value (EUR) |
|---|
Total losses = energy input minus energy billed minus authorised unbilled use. Technical losses are your estimate (for example from an engineering study). The remainder is the non-technical loss indicator: it is whatever the figures leave unexplained, so it includes measurement and billing errors and requires verification. AT&C losses = 1 minus billing efficiency times collection efficiency.
FEEDER TABLE
Compare areas. The table ranks where the indicator is largest, to help choose where to look first.
| Feeder or area | Energy input (kWh) | Energy billed (kWh) | Technical loss (%) | Total loss | Non-technical indicator | Indicator (kWh) |
|---|
Technical loss defaults to the network-wide assumption above when left empty. A larger indicator means the figures leave more unexplained, so it is a reason to review the data and then check on site. It is not a finding about any customer. Feeder-level data usually carries more measurement error than network totals.
Starting values are illustrative placeholders, not benchmarks and not figures for any utility. The calculators organise your numbers and show what remains unexplained. They do not detect or confirm loss, fraud or theft, and nothing here is advice or a promise of savings. Methods and reference bands should be confirmed by a qualified water-loss or network engineer. Results are indicators that require verification and human review.