South Africa's dam levels are published every week by the Department of Water and Sanitation (DWS) in its Weekly State of Dams report, which tracks roughly 218 dams holding more than 90% of the country's managed water storage. The single number most people are looking for — what share of capacity the country's dams are holding right now — is a capacity-weighted average of those dams, and it moves with the seasons and the rainfall region. This guide explains where that figure comes from, how it breaks down across the nine provinces, and where to read the live level for any individual dam. The current national figure and the province-by-province map are on the South Africa dam levels page.
Key takeaways
- South Africa's dam levels come from the DWS Weekly State of Dams report — updated weekly and covering about 218 dams that together hold more than 90% of national storage. reservoirs.earth mirrors it on the South Africa page.
- The national figure is a capacity-weighted average, not a simple average of percentages. A large dam such as Gariep moves the national number far more than a small farm dam does.
- Storage is very unevenly spread. The Free State alone holds more than half of national capacity, anchored by Gariep and Vanderkloof on the Orange River; Gauteng, the economic heartland, stores almost none of its own water and leans on the Integrated Vaal River System.
- The Western Cape's 2017–2018 "Day Zero" crisis is why the country watches these numbers closely — Theewaterskloof, Cape Town's largest dam, fell close to empty.
- You can track any single dam — Midmar, Sterkfontein or Kammanassie — on its own page, with the latest reading and multi-year history.
Where South Africa's dam-level data comes from
There is one authoritative source for national dam levels: the Department of Water and Sanitation (DWS) and its Weekly State of Dams report. DWS measures the water in every major state dam continuously to run releases and supply, and publishes a consolidated snapshot once a week — usually on a Monday. Each dam is expressed as a percentage of its full supply capacity (FSC), the volume it holds when filled to its design level.
The report covers around 218 dams, which between them account for more than 90% of South Africa's managed storage, so the weekly figure is a genuine read on national water security rather than a sample. reservoirs.earth re-publishes those DWS readings on each dam's page, adds the multi-year history, and rolls them up into the national and provincial view.
The national picture
South Africa's monitored dams hold a combined full supply capacity of roughly 29 billion m³ (about 29 km³). The headline "% full" you see for the country is the total water currently stored divided by that total capacity — a capacity-weighted average. That weighting matters: Gariep alone (full supply capacity ~4,904 Mm³) carries more weight than hundreds of small dams combined, so the national number tracks the big Orange and Vaal system dams more than anything else.
Read the national figure with that in mind. A single wet province can prop up the average while another runs dry, which is why the province breakdown and individual dam pages matter as much as the country-wide percentage. The live national figure updates with each DWS release on the South Africa dam levels page.
Province by province
Storage is spread very unevenly across the nine provinces. The short version:
- Free State — the largest by a wide margin, holding more than half of all national capacity. It anchors the country's two biggest dams, Gariep and Vanderkloof on the Orange River, plus the Vaal Dam and the strategic Sterkfontein Dam.
- KwaZulu-Natal — the second-largest store, where the Umgeni system and Midmar Dam supply Durban and Pietermaritzburg.
- Mpumalanga — sits over the Vaal headwaters; dams such as Grootdraai and Jericho feed the Vaal system and the power stations on the Highveld.
- Western Cape — a winter-rainfall region whose supply turns on dams like Theewaterskloof; the Klein Karoo's Kammanassie Dam sits in the same province.
- Eastern Cape — supplied in part by Kouga Dam and a string of smaller dams.
- Limpopo — many small-to-mid dams including Vondo.
- North West — dams such as Klerkskraal on the Mooi River.
- Northern Cape — little local storage; Boegoeberg Dam regulates Orange River supply.
- Gauteng — the smallest local store of all. The country's economic heartland keeps almost no water of its own and depends on the Integrated Vaal River System, including transfers from the Lesotho Highlands.
Each province page shows the current capacity-weighted fill for that province and lists its dams.
Major dams to watch
These are the dams that carry the national figure (and the ones people search for most), with their full supply capacity from DWS data. Each links to a live page with the latest reading and history:
- Gariep Dam — Free State, Orange River. ~4,904 Mm³ — South Africa's largest dam.
- Vanderkloof Dam — Free State, Orange River. ~3,137 Mm³ — the second-largest.
- Sterkfontein Dam — Free State. ~2,617 Mm³, a 90 m wall completed in 1981; a strategic off-channel reserve for the Vaal system.
- Vaal Dam — on the Free State–Gauteng border. ~2,561 Mm³ — the supply backbone for Gauteng.
- Theewaterskloof Dam — Western Cape. ~479 Mm³ — Cape Town's largest dam and the centre of the Day Zero crisis.
- Grootdraai Dam — Mpumalanga, Vaal River. ~350 Mm³.
- Midmar Dam — KwaZulu-Natal, Umgeni River. ~236 Mm³, a 46 m wall completed in 1965.
- Kouga Dam — Eastern Cape. ~126 Mm³.
- Jericho Dam — Mpumalanga, Mpama River. ~59 Mm³.
- Kammanassie Dam — Western Cape, Klein Karoo. ~34 Mm³.
What "% full" actually means
A dam's level is reported as a percentage of its full supply capacity — the volume held when water sits at the dam's full supply level. So 60% full means the dam is holding 60% of its design storage, not 60% of the physical structure.
Two things trip people up. First, a reading can briefly read above 100%: during heavy inflows water can rise above the full supply level into the flood-storage zone before it is released. Second, a single weekly reading says little on its own — what matters is the trend across a season and against previous years. The multi-year chart on each dam page (and on the national page) is there for exactly that.
Why South Africa's dam levels matter
South Africa is a water-scarce country, and the weekly dam figure is its most direct gauge of supply risk. The clearest illustration was the Western Cape in 2017–2018: a multi-year drought drew Cape Town's supply dams, led by Theewaterskloof, down toward empty, and the city began counting toward "Day Zero" — the date taps would be switched off. Severe restrictions and better rains pulled it back, but it reset how the country reads these numbers.
The stakes are not only urban. Irrigated agriculture is the largest single user of South Africa's stored water, and Gauteng's economy runs on water moved in from the Vaal system and Lesotho rather than stored locally. A falling dam level is an early warning for farms, cities and power stations alike — which is the case for publishing it openly and often.
FAQ
What is the current dam level in South Africa? It changes every week. The live, capacity-weighted national figure — and the breakdown by province — is on the South Africa dam levels page, sourced from the DWS Weekly State of Dams report.
How deep is Sterkfontein Dam? Sterkfontein Dam is held back by a wall about 90 m high and has a full supply capacity of roughly 2,617 Mm³, making it one of South Africa's largest dams. It sits in the Free State and acts as a strategic reserve for the Vaal system.
Which province has the most dam storage? The Free State, by a wide margin — it holds more than half of national capacity, anchored by Gariep, Vanderkloof, the Vaal Dam and Sterkfontein. Gauteng has the least local storage despite being the economic heartland.
How often are South African dam levels updated? DWS publishes the Weekly State of Dams report once a week, typically on a Monday. reservoirs.earth refreshes its dam and country pages from that release.
Where can I check a specific dam's level? Each dam has its own page with the latest reading and a multi-year history — for example Midmar, Jericho or Kammanassie. You can search any dam from the South Africa page.
Were Cape Town's dams ever close to empty? Yes. During the 2017–2018 drought the city's supply dams, led by Theewaterskloof, fell to very low levels and Cape Town counted down to a planned "Day Zero" before rains and restrictions averted it.
South Africa publishes its dam data openly and weekly — which is unusual globally. See how that openness compares on the Reservoir Transparency Index.