Water balance by country · Updated 2026-09-29
Water balance and No Drop in South Africa: municipal NRW, the WRC water balance and pressure management
How South African municipalities calculate the IWA water balance for the Department of Water and Sanitation's No Drop programme, the WRC water-balance model, and why pressure management is the first lever.
Calculator settings for South Africa
- Units
- Metric
- Benchmark category
- Standard for metros; low & middle income for rural municipalities
- Meter location
- Boundary in formal areas; unmetered/flat-rate in many informal settlements
- Supply
- Continuous in metros; intermittent in some rural and stressed systems
- Reporting
- DWS No Drop certification; municipal Water Services Development Plans; WRC water balance and benchmarking
South Africa reports municipal water losses through the Department of Water and Sanitation's No Drop programme, which scores each water services authority on its water balance, NRW and water-loss management. The Water Research Commission developed the standard South African water balance model on the IWA framework and has published national benchmarks for more than a decade; national NRW has sat in the 40–47% range, with metros generally better than district municipalities.
South African specifics
- Free basic water (the first 6 kL per household per month) is authorised consumption — bill it at zero, but it is not NRW. Put it in billed metered or billed unmetered according to how it is recorded, and keep it out of the loss components.
- Informal settlements with communal standpipes are unbilled authorised consumption; estimate from population and standpipe flow surveys.
- Illegal connections and meter bypasses are material in many municipalities; the WRC's guidance suggests survey-based estimates with wide bands.
- Meters are at the boundary in formal areas (0–2 m of service pipe).
- High pressures in hilly metros (Cape Town, Durban, Johannesburg's ridges) are why pressure management has delivered such large savings — Emfuleni's Sebokeng/Evaton scheme is the textbook case. Enter pressure by zone and use the what-if lever to size a PRV programme.
Typical results
Metros sit around ILI 4–8 with real losses of 200–400 litres per connection per day; many district municipalities are in band D. Because the No Drop scorecard rewards a complete and reliable balance as much as a low number, the completeness score and uncertainty bands in this calculator map directly to what assessors look for.