Cape Town Day Zero

Cause

An exceptional multi-year rainfall deficit against a supply system dependent on surface reservoirs, with demand that had grown faster than resource development.

Impact

• Dam storage fell below 20% of capacity
• Personal consumption restricted to 50 litres per person per day
• City-wide demand roughly halved

Response

A restriction regime combined with tariff changes, pressure management, a public water map showing household consumption, and intensive communication. Day Zero was never reached.

Aftermath

The most successful large-scale urban demand reduction on record: Cape Town cut consumption by more than half and avoided failure. It became the reference case for demand management as a drought response, and for the political difficulty of maintaining low consumption after rains return.