By Lewis van der Bank, N.Dip Civil Engineering, Penetron Africa
The Problem We’re Facing
In my work supporting concrete water infrastructure durability projects across Southern Africa, one issue keeps surfacing: critical water assets are failing far earlier than they should.
Africa is approaching a critical breaking point in water security. Across the continent, much of the infrastructure that communities still depend on, particularly in countries such as Mozambique, dates back to the colonial era. These ageing reservoirs, treatment plants and storage tanks are operating at or beyond their intended design life, yet they remain the backbone of public water supply systems.
As Wiljee Blom has observed, some newly constructed facilities are already showing signs of deterioration equal to, or worse than, structures built more than 50 years ago. This trend is being observed across multiple regions on the continent, and it’s deeply concerning.
Safe and reliable water supply depends on the integrity of these assets and national key infrastructure, most of which is constructed from concrete. When concrete begins to crack or leak, the consequences are immediate and severe: contamination of drinking water, rising operational costs, interrupted supply, and in extreme cases, risks to public health and safety. The materials and construction methods selected for new and existing concrete structures therefore represent a fundamental development priority.
Why Water Infrastructure Durability Matters More Than Ever Ever
For municipalities and both rural and urban utilities, durability determines whether a system will serve communities for generations or fail prematurely. Rural systems face particularly harsh conditions, including limited maintenance funding, fewer technical teams and increasing exposure to climate extremes such as prolonged droughts and intense rainfall.
Short-term remediation strategies, including surface-applied coatings and membranes, often shift long-term costs back onto communities. The pattern repeats itself: recurring water shortages, contamination risks, emergency repairs. The challenge is clear. Water infrastructure must be designed to last, protect water quality and reduce lifecycle costs.
How Crystalline Systems Work Differently
Crystalline waterproofing systems offer an alternative approach, and I’ve seen the difference they make firsthand. Unlike surface membranes, crystalline admixtures integrate into the concrete itself. They react with moisture and unhydrated cement particles to form microscopic crystals within the concrete matrix, permanently reducing permeability by sealing pores and microcracks.
This approach eliminates the need for reapplication and avoids materials that may introduce contamination risks. When microcracks occur, the presence of moisture can reactivate the crystalline process, enabling internal engineered healing. In practice, this supports reduced maintenance requirements, safeguards potable water quality and contributes to lower whole-life costs.
Real Projects, Measurable Results
The benefits of integral concrete protection are already visible in operational infrastructure. At the Crown Gardens 2ML Pressure Tower in Johannesburg, crystalline admixtures were specified to support the long-term durability of a high-capacity municipal asset supplying a growing urban population. By integrating durability into the concrete at the construction stage, the structure was designed for resilience, reduced maintenance and secure water delivery.
In Mozambique and other parts of the continent, many existing reservoirs aren’t designed with ring-feed systems. Conventional repair methods, such as internal linings, therefore require tanks to be drained and taken offline. For rural utilities, this often means cutting water supply to entire communities. Crystalline technology offers a practical alternative because it can be applied from the negative side of the structure, permanently sealing leaks without decommissioning the reservoir.
A further example is the Polana Serena Hotel, which has been in service for over a century and relies on ageing water storage infrastructure. Rehabilitation of the domestic water reservoir was carried out from the negative side whilst the reservoir remained operational. This allowed repairs to be completed without disrupting hotel operations or introducing contamination risks, extending the service life of a critical asset whilst maintaining continuous water supply.
What This Means for Africa’s Development
This discussion extends beyond any single technology or project. Decisions made at the design stage are directly linked to Africa’s broader development goals: reliable water supply, reduced public health risks and infrastructure that makes better use of limited public funds.
In most African countries, where rural settlements are dispersed, budgets are constrained and climate extremes are severe, durability isn’t optional. Building once, and building correctly, is essential to protecting communities and supporting long-term economic growth. We’ve seen what happens when shortcuts are taken, and the cost is always paid by the communities who can least afford it.
Building for the Long Term
Securing Africa’s water future depends on building better, not simply building more. Engineers, architects, municipalities and funders must prioritise integrated, non-toxic waterproofing strategies at the design stage. Equally important is the training of local teams to apply and inspect durable systems, reducing dependency and improving long-term outcomes.
The concrete choices made today will determine whether future generations inherit resilient water infrastructure or face recurring failures and public health risks. The path forward is clear: specify for durability and implement with intent.
About the Author
Lewis van der Bank holds a National Diploma in Civil Engineering and is part of the technical team at Penetron Africa. He works with engineers, contractors and municipalities on concrete durability and water infrastructure projects, with a focus on long-term performance and sustainable asset protection.