South Africa’s water infrastructure is under mounting strain due to climate variability, ageing systems, and institutional breakdowns. The 2023 Blue Drop Progress Report revealed that nearly half of the country’s water supply systems are at high or critical risk. In response, national initiatives like the Water Services Amendment Bill and the National Water and Sanitation Master Plan call for urgent investment in reliable, long-lasting solutions.
This is where stainless steel plays a vital role. Known for its corrosion resistance, durability, and low maintenance needs, stainless steel offers a practical, proven way to improve water infrastructure performance.
Its use in both above- and below-ground systems can significantly reduce leaks, improve hygiene, and lower long-term operating costs. Drawing on international examples such as Tokyo and Seoul, and successful South African cases like the Drakenstein Municipality, this article explores how stainless steel can support sustainable water management and serve as a key driver of national water security…
Understanding the Global Water Crisis
The global water crisis refers to the growing scarcity of clean, accessible water resources. Around 703 million people worldwide, about one in ten, lack access to water, and more than two billion lack safe drinking water. Even in countries with adequate natural resources, scarcity is often caused by poor infrastructure, contamination, mismanagement, or conflict.
This crisis affects basic hygiene, public health, and economic activity. In South Africa, regions swing between extreme drought and destructive flooding. Climate change is expected to intensify these conditions, while ageing infrastructure and underperformance by municipalities make matters worse. Scarce water also drives up costs, increasing the financial burden on communities.
Economic and Technical Benefits of Stainless Steel
Stainless steel brings significant long-term economic and operational benefits to the water sector. It has a strong track record in water treatment applications, thanks to its excellent corrosion resistance, durability, and hygienic qualities. Austenitic stainless steels (300 series) are especially well-suited to the harsh conditions found in water systems, but duplex and other specialised grades are also widely applicable.
Why Stainless?
Stainless steel forms a self-healing passive film that protects it from corrosion in most environments without the need for coatings. This simplifies design and eliminates concerns about coating degradation, leaching, and ongoing maintenance. As a result, there’s no need to over-specify wall thicknesses to allow for corrosion loss.
Its corrosion resistance ensures stainless steel piping and components retain their performance over decades, reducing both operating costs and unplanned outages. At the end of their lifecycle, these materials retain residual value and are typically fully recycled.
With no internal corrosion or scaling, stainless steel preserves flow efficiency. Its strength and ductility allow for lightweight, thin-walled designs that are easier to transport and install, especially when welded or joined using loose flanges. Duplex grades enable further weight reduction in large installations like buried pipelines or bridge spans.
Best Practices in Design and Fabrication
For stainless steel to perform as intended, correct grade selection must be followed by attention to fabrication details. Welded joints should be prioritised to avoid crevices where corrosion could initiate. While galvanic corrosion is rare, it may occur if stainless steel is paired with less noble metals like carbon steel or galvanised iron. Proper electrical insulation or using compatible materials is essential in such cases.
Welding is the most common point of failure, but problems are avoidable with best practices: full-penetration welds, elimination of heat tint, and thorough post-weld cleaning. Contamination with iron particles can cause rust staining or pitting and should be avoided with proper material handling and workshop discipline.
Case Study: Tokyo’s Long-Term Stainless Steel Strategy
Tokyo once suffered massive water losses due to an ageing and fragmented infrastructure. In 1945, water loss rates exceeded 80%. While improvements brought this down to 30% by 1950, continued urban expansion kept the physical volume of lost water unsustainably high.
The city responded with a systematic intervention based on three pillars:
- Service Line Replacement: The “last metre” of delivery often still in lead-was replaced with corrugated stainless steel pipe, offering flexibility and reducing joint-related leaks. Other components such as flanges, pumps, and valves were also upgraded to stainless steel.
- Proactive Leak Detection: Scheduled inspections covered the entire system every 10 years, supported by a 24-hour mobile leak detection unit for rapid repairs.
- Technology and Skills Development: Ongoing innovation in detection methods, alongside skills development through international partnerships, created a sustainable programme.
By 2011, the city reduced its water loss rate to just over 2%. Annual leak repairs dropped from 69 000 in 1980 to 12 800 in 2011. The knock-on effects included fewer traffic disruptions, better mobility, and a 53 700 ton annual reduction in CO₂ emissions, the equivalent of removing 22 900 cars from the road. In addition, water loss fell from 133 000 in 1980 to 6 400 cubic metres per day by 2011 equating to a financial saving of $480-Million a year.
South Africa: Local Proof of Concept
South Africa’s average water loss rate exceeds 35%, but some municipalities have demonstrated that world-class performance is possible. For example, the Drakenstein Municipality in the Western Cape reduced losses from over 30% two decades ago to below 10% today. Its strategy mirrors Tokyo’s:
- Corrugated stainless steel piping (Grade 304 above ground, 316 underground)
- Fast response to leaks
- Planned preventative maintenance
The results speak for themselves: significantly lower water loss, reduced maintenance costs, and a more resilient infrastructure. It proves that stainless steel is not just suitable for high-income urban centres, but adaptable to local conditions in South Africa.
A Strategic Material for South Africa’s Future
It’s clear that stainless steel offers unmatched long-term value for water infrastructure particularly in a country where system failure often comes down to materials and maintenance. South Africa does not need to invent a new solution given that global case studies and local proof points already exist.
The path forward involves prioritising quality over short-term savings, investing in competent municipal management, and committing to long-term infrastructure improvement. Stainless steel may carry a higher upfront cost, but the lifecycle savings, namely fewer leaks, reduced energy use, better hygiene and recyclability, far outweigh the initial outlay.
Conclusion
South Africa stands at a water crossroads. With increasing pressure on supply, failing infrastructure, and environmental stress, the country needs robust, future proof solutions. Stainless steel delivers the performance, reliability, and economic logic required to meet this challenge.