The future of Cape Town's water · honest framing

Can desalination
save Cape Town?

A new desalination plant at Paarden Eiland will start producing drinking water around 2030. Together with water reuse and groundwater, the City plans roughly 300 megalitres a day of new supply by the end of 2031 — and uses about 1,025 every day already.

This page sets the planned new sources next to today's daily use — drawn to the same scale, with each figure linked to its source. No alarm, no spin. Just the numbers.

Demand vs supply · drawn to scale
Cape Town water demand vs new water sources by 2031 Stacked horizontal bars comparing current daily demand of about 1,000 megalitres per day to the planned 300 megalitres per day of additional supply from desalination, water reuse, groundwater and management interventions by 2031. CAPE TOWN · WATER · 2026 CAPETOWNDAMLEVELS.CO.ZA Can desalination save Cape Town? The City's planned new water sources, drawn to scale against today's demand. WHAT CAPE TOWN USES EVERY DAY ~1,000 ML/day 1,025 ML/day average through 2025 · target benchmark 975 ML/day WHAT TODAY'S DAMS CAN SUPPLY · WHEN FULL depends on rain In drought, supply falls. The 2018 Day Zero crisis was the system at 21%. WHAT NEW PROJECTS WILL ADD BY 2031 +300 ML/day EVERYTHING NEW · STILL SMALLER THAN DEMAND DESALINATION 70 · WATER REUSE 100 · GROUNDWATER 100 · MANAGEMENT 30 FIGURES · CITY OF CAPE TOWN · WATER STRATEGY 2019 · OCT 2025 STATUS REPORT · ML/DAY = ONE MILLION LITRES PER DAY

The top bar is what Cape Town drinks, washes and waters its gardens with on an average day. The middle bar is what the dams supply when full — they currently meet demand, but only when it has rained. The bottom bar is everything new the City has planned: meaningful, but smaller than today's demand on its own.

The three new sources · in plain terms

Each project does something different and each has trade-offs. The City's strategy is to combine all three so that the city is no longer entirely dependent on rainfall.

01 / 03 Desalination
70 ML/day
About 7% of current daily use
50–70 ML/day during ramp-up; 70 ML/day at design capacity
Where it stands
Procurement begins 2026 · first water 2030 · full operations targeted November 2031
What it costs
About R5 billion (excluding VAT, 2023 prices)
How it works
A plant on the Atlantic coast pulls in seawater and pushes it at very high pressure through fine membranes. The membranes block the salt and let clean water through. The clean water is treated, then added to the city's drinking-water network.
The honest catch
Desalination uses a lot of electricity — running this plant alone needs roughly the power of a small town. Removing the salt also leaves a concentrated brine that has to be discharged back into the sea, which can affect marine life close to the outfall if not carefully managed.
Sources
02 / 03 Water reuse
100 ML/day
About 10% of current daily use
70 ML/day at first; 100 ML/day at ultimate capacity
Where it stands
Procurement begins 2026 · first water targeted financial year 2030/31
How it works
Treated wastewater from the Zandvliet sewage works is run through extra purification — ozone, carbon filters, ultrafiltration, ultraviolet light — until it meets drinking-water standards. It is then blended with dam water (roughly 20% reuse, 80% dam) before going into the supply.
The honest catch
The biggest barrier is public acceptance — many people feel uneasy about drinking water that started as sewage, even after multi-stage purification meets South African and WHO drinking-water standards. The plant is also expensive to build and is being procured as a public-private partnership.
Sources
03 / 03 Groundwater
100 ML/day
About 8–12% of current daily use
80 ML/day from current Phase-1 wellfields, up to about 120 ML/day at full development
Where it stands
Phase-1 wellfields already online; full programme continues through the decade
How it works
Boreholes pump water from rock and sand layers underground — the Cape Flats aquifer south-east of the city, the Atlantis aquifer to the north, and the deep Table Mountain Group aquifer near Steenbras. The water is chlorinated and fed into the city's network.
The honest catch
Aquifers are recharged by winter rainfall — the same rain the dams depend on. If too much water is pumped out, the underground level drops, which damages wetlands and lets seawater seep into coastal aquifers. Sustainable yield is the limit, not the maximum that can be pumped.
Sources
The other half of the strategy · using less

New supply and lower demand aren't competing strategies. The City's plan is both. Saving 100 megalitres a day costs nothing and delivers immediately; building 100 megalitres a day of new infrastructure costs billions and takes years.

When does new water arrive?

The new sources don't all arrive on the same day. Procurement begins in 2026, first water flows around 2030, and the full 300 ML/day is targeted by the end of 2031 — already a year later than the 2019 strategy planned.

Cape Town water supply timeline 2026–2035 Horizontal timeline showing when the City's planned new water sources come online. Today's daily demand is drawn as a horizontal line at 1025 ML/day. A wedge growing from 2030 represents the +300 ML/day delivered by the New Water Programme by 2031. TODAY'S DAILY DEMAND · 1,025 ML/DAY NEW SOURCES COMING ONLINE +300 ML/DAY · BY 2031 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 NOW PROCUREMENT BEGINS 2026 FIRST WATER ONLINE 2030 NWP TARGET 2031 · Dec

The City's October 2025 progress report records that the programme's completion has slipped from 2030 to December 2031, attributed to procurement complexity, regulatory approvals, and rising infrastructure costs.

The honest synthesis

New supply helps. Saving water helps. Neither alone is enough. The next decade of Cape Town's water security is about both — building 300 megalitres a day of rainfall-independent supply, and continuing to use less of what falls.

Desalination won't replace the dams. It complements them. The honest reading of the City's own published figures is that even with every planned project delivered on time, the system is balanced — not abundant — and Cape Town will still depend on winter rainfall and household discipline for the foreseeable future.

→ How to save water at home → Today's dam levels