Cape Town Dam Levels Drop to 47.8% as Drought Warning Returns

Cape Town's six major supply dams stood at 47.8% capacity on April 1, down from 67.4% at the same point in 2025, according to the City of Cape Town's weekly water dashboard. The 20-percentage-point gap is the largest year-over-year deficit since 2018, when the city came within weeks of shutting off municipal taps in what became known as "Day Zero."

The city supplies water to 4.7 million residents. If dam levels fall below 40% by May, Level 3 water restrictions will automatically take effect, limiting households to 105 litres per person per day, city water director Zahid Badroodien told the Cape Town city council on March 28.

Why Levels Are Falling

The Western Cape received 31% below-average rainfall between October 2025 and March 2026, according to the South African Weather Service. The shortfall was most severe in the catchment areas feeding the Theewaterskloof Dam — the city's largest reservoir — which sat at 38.2% on April 1.

Theewaterskloof holds 41% of Cape Town's total dam capacity. During the 2017-2018 crisis, it dropped to 13%.

Rising temperatures have compounded the rainfall deficit. Average maximum temperatures in the Western Cape ran 1.8°C above the 30-year mean for the October-March period, according to weather service data, increasing evaporation from open reservoirs.

"The combination of reduced inflow and increased evaporation is a double hit," said Piotr Wolski, a hydrologist at the University of Cape Town's Climate System Analysis Group. "We are entering the dry season with significantly less buffer than the city needs."

Demand Pressure

Cape Town's population grew by an estimated 147,000 people in 2025, according to Statistics South Africa's mid-year estimate. The growth rate of 3.1% outpaced the national average of 1.2%, driven by domestic migration from Gauteng and the Eastern Cape.

Daily water consumption averaged 892 million litres in March 2026, compared with 841 million litres in March 2025 — a 6% increase that Badroodien attributed to population growth and a warmer-than-normal summer.

The city has invested R8.2 billion ($440 million) in water infrastructure since the 2018 crisis, including three desalination plants, aquifer extraction systems, and water recycling facilities. Those systems now provide approximately 12% of the city's supply, up from near zero in 2017.

But the new capacity has been absorbed by population growth rather than building additional resilience, according to an audit by the Western Cape government released in February.

Regional Context

Cape Town is not alone. The Nelson Mandela Bay metro (Port Elizabeth) has been under severe water restrictions since 2022, with its Kouga Dam at 11.3% as of March 30. Gqeberha residents have been limited to 50 litres per person per day for over a year.

Across southern Africa, drought conditions have intensified. Zambia declared a national drought emergency in February after hydroelectric output from the Kariba Dam fell to 10% of capacity. Zimbabwe's Harare has been rationing water to 12 hours per day since January.

The Southern African Development Community's climate services centre warned in its March outlook that below-normal rainfall was likely to persist across the region through June, driven by a weakening La Niña pattern and above-average Indian Ocean temperatures.

What Happens Next

Cape Town's water department will release updated dam projections on April 7 based on revised seasonal forecasts. If the current depletion rate continues, dams will reach 40% — the restriction trigger — by late April.

Mayor Geordin Hill-Lewis urged voluntary conservation in a public address on March 30, asking residents to limit showers to two minutes and stop irrigating gardens.

"We are not at Day Zero," Hill-Lewis said. "But we are at the point where every litre counts."

The city's next formal dam level report is due April 8. Winter rains, which typically begin in May, will determine whether Cape Town faces a difficult dry spell or a full-scale water crisis.