When the Water Fights Back: Why Western Cape Plumbing is Under Siege
Published on October 13, 2025
The Western Cape is no stranger to water crises. From Day Zero fears to ongoing drought management and water restrictions, the province has learned to treat every drop with care. But there’s a lesser-known crisis brewing beneath the surface in the very pipes that deliver that water.
What if we told you the water in the Western Cape isn’t just hard to come by, it’s hard on your plumbing.
Trouble Zones: Where Water Quality Is Worst
According to the City of Cape Town Inland Water Quality Technical Report (2024), four high-risk zones consistently show the poorest water quality performance due to a combination of salinity, turbidity, microbial content, and chemical imbalance:
- Central False Bay: Highly variable quality with high turbidity and organic matter, and according to Kretzmann (2024), 382 million liters of untreated sewage are released into Cape Town’s rivers and oceans, with 216 million liters going into False Bay every day.
- Lagoon Beach (Milnerton): Influenced by stormwater runoff, high TDS, and salinity spikes.
- Macassar to Gordon’s Bay: pH fluctuations, high sulfate content, and intermittent supply issues.
- Three Anchor Bay (Sea Point): High chlorine demand, biofilm buildup, and infrastructure age.
These are not remote areas; they’re urban zones with thousands of households and businesses suffering the consequences: leaks, corrosion, pipe failures, and costly repairs
Figure 1: Watkins, K, 2024. Chronic water pollution at lagoon beach – report.
Figure 2: Van Zyl, I, 2023. Concerns as three anchor bay water turns brown.
Why Traditional Systems Are Failing
Copper
In Macassar and Three Anchor Bay, multiple plumbers report pinhole leaks in copper pipework as early as 3 to 5 years post-installation. The culprit? Low pH water combined with turbulent flows and high chlorine levels.
MLP (Multi-Layer Pipe)
In Lagoon Beach and Gordon’s Bay, UV exposure and poor water stability cause seal degradation and inner aluminum corrosion, a known weakness in mixed-material systems.
Steel/Galvanized Systems
Older infrastructure in Central False Bay is full of rusted, non-functional galvanized pipework, costing municipalities and schools millions in reactive maintenance annually.
While copper might hold its own on the first day of installation, the Western Cape’s aggressive water conditions tell a different story over time. When tested under SANS 198 flow assessments at P.E.S.C., Untwists PP-R MonoGold pipe showed flow rates within just 5% of copper at 3 bar pressure, 32.65 L/min vs 34.37 L/min for 15 mm, and 40.81 L/min vs 42.96 L/min for 22 mm.
But here’s where the difference truly matters: copper’s internal bore is prone to scaling, pitting, and corrosion, all of which are accelerated by the high chloride, variable pH, and turbidity found in areas like Gordon’s Bay, Lagoon Beach, and Central False Bay. These deposits shrink copper’s flow diameter over time, reducing its performance and increasing maintenance needs. Unitwist, by contrast, features a smooth, non-corrosive inner wall that resists buildup, preserving full flow rate for life. Combine that with our full-bore fittings, no solder lips or compression olives to restrict flow and you get a system that improves its performance edge as the years go on. In the Cape, where water fights back, Unitwist is built to push through.
Figure 3: Hamlin, J, 2025. Tides of controversy: coastal water quality becomes a battleground in Cape Town.
What’s in the Water That’s Wreaking Havoc?
Let’s break it down:
| Parameter | Impact on Plumbing |
| Chloride (Cl⁻) | Causes stress cracking in copper and steel. |
| Sulfate (SO₄²⁻) | Leads to scale and corrosion in steel lines. |
| Low pH (acidic water) | Leaches copper and damages seals. |
| High Conductivity (TDS) | Accelerates corrosion in metal components. |
| Turbidity / Biofilms | Traps debris in fittings, creating microbial corrosion. |
| Chlorine Residuals | Breaks down plastic seals and fittings over time. |
Why Unitwist Is Built for the Western Cape
Western Cape’s water isn’t just hard; it’s harsh. It corrodes metal pipes, cracks plastics, and strips copper overnight. That’s why Unitwist was engineered differently from the start. With zero metal in our fittings, there’s zero risk of corrosion or electrochemical breakdown, even in high-salinity or acidic environments. Our patented slip nut and seal design means leak-free performance without any tools, even under poor water pressure or compromised water quality.
Untwists materials are UV-resistant and pressure-tested in real coastal conditions to avoid cracking or warping. And with no scrap value, our fittings stay in place, unlike copper or brass, which often disappear within hours in theft-prone areas. Backed by a 25-year guarantee and SANS 15874-5 compliance, Unitwist doesn’t just survive the Cape; it thrives in it.
If the Water Won’t Change, Maybe Your Plumbing Should
The Western Cape’s water isn’t going to get less salty, less acidic, or less corrosive any time soon. And most systems just aren’t made to handle that long term.
That’s why Unitwist was built differently from the ground up, for conditions like these.
No metal. No tools. No drama. Just a system that lasts, even when the water doesn’t go easy.
Learn more about Unitwist
Explore the full Unitwist range and see why it’s made for places where the water fights back.
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Bibliography:
Figure 1: Watkins, K, 2024. Chronic water pollution at lagoon beach – report. [Online]. Available at: https://tabletalk.co.za/news/2023-10-11-chronic-water-pollution-at-lagoon-beach-report/ [Accessed 9 October 2025].
Figure 2: Van Zyl, I, 2023. Concerns as three anchor bay water turns brown. [Online]. Available at: https://www.capetownetc.com/news/concerns-raised-as-three-anchor-bay-water-turns-brown/ [Accessed 9 October 2025].
Figure 3: Hamlin, J, 2025. Tides of controversy: Coastal water quality becomes a battleground in Cape Town. Daily Maverick. 9 January. [Online]. Available at: https://www.dailymaverick.co.za/article/2025-01-09-tides-of-controversy-coastal-water-quality-becomes-a-battleground-in-cape-town/ [Accessed 9 October 2025].
Kretzmann, S. 2024. Failing sewage plants continue to pollute false bay. GroundUp. 16 February. [Online]. Available at: https://groundup.org.za/article/failing-sewage-plants-continue-to-pollute-false-bay/ [Accessed 9 October 2025].
City of Cape Town. 2024. City releases annual inland water quality report. [Online]. Available at: https://www.capetown.gov.za/Media-and-news/City%20releases%20Annual%20Inland%20Water%20Quality%20Report [Accessed 9 October 2025].