Cape Town desalination is one piece of a four-part plan to make the city less dependent on rain by 2031: a R5-billion seawater plant, a wastewater reuse scheme, three groundwater wellfields, and the demand discipline that 2018 forced into the system.
In September 2025, the City of Cape Town finally put a price on the desalination plant it has been planning for nearly a decade. Roughly R5 billion in 2023 prices, for a single plant on the Atlantic coast at Paarden Eiland producing 70 megalitres of drinking water a day. Procurement starts in 2026; first water is expected around 2030; full operations are now targeted for the end of 2031.
It is also smaller than people often assume. Cape Town used about 1,025 ML a day on average across 2025. The Paarden Eiland plant, at design capacity, replaces roughly 7 percent of that.
Cape Town’s water future is not a single dam-substitute. It is a portfolio. Three new sources do not need rain — desalination, water reuse, groundwater — and one quiet part has saved more water than all of them combined: the city using less.
The R5-billion plant at Paarden Eiland
The plant lives in a narrow strip of industrial coast between Table Bay Harbour and Milnerton. Atlantic water comes in through an offshore intake, runs through pre-treatment to take out sand and biological matter, and is pushed at very high pressure through reverse-osmosis membranes that block the salt. The clean water is mineralised back to drinking-water chemistry, chlorinated, and pumped into the same network that already carries dam water from the Western Cape Water Supply System into people’s homes.
Cape Town has done this before, briefly. During Day Zero, three temporary plants at the V&A Waterfront, Strandfontein and Monwabisi pulled small volumes of seawater out of the Atlantic on short-term contracts. They were costly, contested in court, and switched off when the dams refilled. Paarden Eiland is the City’s first attempt at a permanent, at-scale plant.
The catch, which the City is candid about in its own documents, is electricity. Reverse osmosis runs roughly the power of a small town. A 70 ML/day plant on a coal-leaning grid carries an emissions footprint dam water does not. The brine the membranes leave behind, twice as salty as the sea it came from, is discharged back into the ocean and has to be modelled carefully so it does not damage marine life close to the outfall. The procurement was criticised as expensive in late 2025 by the Cape Argus.
For the data behind why desalination went from “if needed” to “definitely needed” between 2014 and 2018, see the Cape Town drought case study.
Water reuse: the Faure scheme
The largest single addition in the New Water Programme is not the desalination plant. It is the Faure New Water Scheme, which will treat wastewater from the Zandvliet sewage works to drinking-water standards and put it back into the network.
The process runs treated effluent through ozone, biological activated carbon filtration, ultrafiltration membranes, and ultraviolet disinfection. The output meets the South African National Standard for drinking water (SANS 241) and the World Health Organization’s drinking-water guidelines. It is then blended at roughly 20 percent reuse to 80 percent dam water before being put into the supply.
At full capacity, Faure will add 100 ML a day, about 10 percent of current use. First water is targeted for the 2030/31 financial year.
The catch with water reuse in Cape Town is psychological more than technical. Singapore’s NEWater, the Goreangab plant that has supplied Windhoek since 1968, parts of California and Texas — all of these already drink their wastewater after this kind of treatment. The water is, on chemistry, indistinguishable from any other drinking-water source by the time it reaches the tap. The barrier is the idea of it.
Groundwater: three aquifers around Cape Town
The third leg of the new water plan is groundwater, drawn from three aquifers around Cape Town.
The Cape Flats aquifer sits south-east of the city under the suburbs and townships of the sandy Cape Flats, a shallow primary aquifer that recharges from winter rainfall directly through the dunes. The Atlantis aquifer, north of the city, has been managed since the 1970s with stormwater and treated effluent injected back into the ground to top it up. The Table Mountain Group aquifer is the deep one, fractured sandstone of the same geology that holds up Table Mountain itself, accessed near the Steenbras dams.
Phase-1 wellfields are already online and supplying about 80 ML a day. The full programme could push that up to roughly 120 ML a day, depending on the sustainable yield each aquifer can take without damage.
The catch with Cape Town groundwater is that aquifers are still rain-fed. Pump too much, the level drops, wetlands above lose their feeder springs, and at the coast seawater seeps in to replace what was taken. The limit is sustainable yield, not the maximum a borehole can deliver.
300 ML a day, drawn to scale
Add the three new sources together and you get the New Water Programme’s headline figure: +300 ML a day by the end of 2031, including 30 ML/day from pressure management, leak detection, and metering improvements that recover water already running through the system.
That is meaningful. Against the 1,025 ML/day the city actually uses, it is also less than a third.
The bar above is the entire daily demand. The coloured part on the left is the new water the City is building. The hatched part on the right is the share that still comes from the dams. Even with everything in the New Water Programme delivered on time, rain is still doing the heavy work.
Demand is the faster lever
The other half of the answer to “can Cape Town stop running out of water?” does not show up on a procurement budget. It is the city using less.
Between 2015 and 2018, Cape Town’s combined daily water use fell by about half. Citywide consumption dropped from a peak of roughly 1,200 ML/day in 2014 to around 555 ML/day by April 2018. Residential per-person use went from around 183 litres a day to 84. That happened with no new water plant, no desalination, no reuse — just progressive tariffs, water-management devices, pressure management, and a relentless public campaign. Oxfam’s Avoiding Day Zero is the standard reference for how it was done.
The headline number obscures who actually saved. Pre-drought consumption in Constantia, Newlands and Bishopscourt ran at two to three times the citywide average, on thirsty gardens and swimming pools. The collapse from 183 to 84 litres a day was, in practice, those households cutting hard. In Khayelitsha, Mitchells Plain and Philippi, where many residents already drew water from communal taps and had been living at or below the Day Zero per-person target for years, there was little headroom to give back.
That lesson sits awkwardly with the optimism around new infrastructure. New supply takes years to build, billions of rand to finance, and adds emissions. Demand reductions take weeks, cost a fraction of that, and can be reversed when the rain comes back. A working assumption among the City’s water engineers, written into the 2019 Cape Town Water Strategy, is that long-term per-capita use should sit closer to the 2018 floor than to pre-drought levels.
That assumption is being tested. Citywide consumption ran above the City’s 975 ML/day conservation benchmark through 2025, in part because metropolitan population continued to grow while per-capita use crept back up.
The pipe-replacement programme is the boring counterpart that actually delivers. In the three years to the end of 2025, the City replaced 171 km of leaky water main. Replacing pipes claws back losses without building anything new. It is the cheapest megalitre on the menu.
The timeline keeps slipping
The New Water Programme was originally promised for 2030. The October 2025 progress report from the City pushed that to December 2031. Procurement complexity, regulatory approvals, and rising infrastructure costs were named, in the careful language of local-government progress reports.
A year of delay on a programme this size is not unusual. Capital infrastructure projects everywhere slip. The point worth holding onto is what the slippage means for the dams between now and 2031: they still do almost all of the work.
What the future actually looks like
Cape Town desalination, on its own, does not save the city. With water reuse, groundwater, leak repair and the demand discipline that 2018 forced into the system, it makes Cape Town much harder to run dry.
The combined system on the most recent reading sits at 48.3%, against 59.9% the same week last year, with daily use just under the 975 ML/day target. The new sources are still five to seven years out at full delivery. The dams are still where Cape Town’s water comes from. They are also getting harder to depend on alone, on the rainfall pattern climate models project for the southwestern Cape: drier winters and less reliable refill.
For the question of what saves the city, the most accurate answer is several things, no one of them by itself. Cape Town desalination is one. Demand discipline, the part that took half the system’s daily use off the books in three years, is still the most leveraged. Watch for the procurement awards in 2026, and for today’s combined dam levels to see what the rain does between now and then.