Windhoek, Namibia
#00173
Case study of
#00185 Potable reuse of treated wastewater behind multi-barrier treatment and long acceptance-building
Implementer
City of Windhoek / Windhoek Goreangab Operating Company
Timeline
Since Jan 1, 1968
Location
Description
Windhoek pioneered direct potable reuse in 1968, making it the world's first city to return purified wastewater directly to its drinking supply. The New Goreangab plant (2002) produces about 21,000 m³/day, supplying roughly 25% of the city's water and up to 35% in drought years. Because Windhoek is inland, RO brine disposal is impossible, so the plant runs a multi-barrier train without reverse osmosis; strict segregation of industrial sewage from the domestic stream feeding the plant is a prerequisite. A DPR II expansion, backed by roughly $43M from KfW, aims to raise reuse to about 50% of supply.
Metrics
4Funding
Lessons learned
- Direct potable reuse has been safe in continuous municipal operation since 1968 when the multi-barrier train is run rigorously.
- Inland cities can run potable reuse without RO, but only with strict segregation of industrial sewage from the domestic stream feeding the plant — this is a non-negotiable operational prerequisite.
- Decades of visible, incident-free operation are themselves the strongest acceptance-building tool; the local framing used was that water should not be judged by its history, but by its quality.
Documented Jul 24, 2026