Water: Navigating a triple nexus – concept to scalable solutions

Proven to boost resource security, cut costs, and drive growth, South Africa’s Water-Energy-Food Nexus needs discussion, with gaps in technology, finance, and policy slowing the scale-up of successful projects

The Water-Energy-Food (WEF) Nexus describes the inextricable links between three critical resources. Energy is essential to pump, treat, and distribute water, while water is a key input for energy plant cooling and generation, and food production. In turn, both water and energy underpin agricultural productivity.

Historically, resource governance has been fragmented, with separate departments and policies for water, energy, and agriculture.

This silo-ed approach risks inefficiency and even counterproductive outcomes, solving one problem while unintentionally worsening another.

For instance, switching from flood irrigation to high-pressure sprinklers would reduce water use, but it does require significantly more electricity to pump the water.

This change may reduce water stress but worsen energy costs. The WEF Nexus advocates an integrated, technology-driven model that balances water security, energy access, and food resilience, supporting a transition towards a circular economy.

Low-hanging fruit enabling viable nexus models

Innovation plays a pivotal role in operationalising the Nexus, where solutions build on existing technologies, applied in integrated ways.

For instance, water reuse systems for irrigation or industrial processes, apps that optimise resource flows, and conduit hydropower that installs turbines in existing pressurised water pipelines to generate electricity.

Biogas production and nutrient harvesting from agricultural residues and wastewater provide further opportunities, creating renewable energy and fertiliser while reducing environmental impacts. Such use cases can reduce operating costs, enhance resource security, and contribute to broader climate resilience objectives.

How the financial world views the WEF nexus

Financing remains a decisive factor in scaling nexus-aligned projects. Commercial banks are beginning to treat such initiatives as critical infrastructure, aided by blended finance models that combine development funding with private capital.

Rising traditional resource costs and maturing technologies are improving commercial viability, making these projects attractive to asset managers with sustainability mandates.

Significantly, financial institutions are encouraging proactive investment before resource crises disrupt operations.

Furthermore, financiers no longer view these projects as purely sustainability measures but as economic opportunities that can stimulate industry, create jobs, and foster micro-economies.

Barriers to adoption and examples on the way

Despite the potential, policy frameworks remain outdated, often preventing water reuse or nutrient recovery despite their proven benefits. Skilled personnel with interdisciplinary expertise are in short supply, and many businesses remain unaware of the severity of resource challenges or the commercially viable solutions available. Early-stage innovations, in particular, struggle to secure funding without track records.

A business-as-usual mindset persists in most sectors, absorbing rising costs or passing them on to consumers rather than investing in systemic change. Nonetheless, initiatives demonstrating the value of integrated approaches include South African Brewery’s Ibhayi Brewery in the Eastern Cape.

The brewery uses a low-cost wastewater treatment system linked to hydroponics, agriculture, and biogas production. Bloem Water’s conduit hydropower project powers its offices entirely off-grid, inspiring the City of Tshwane to integrate similar systems across its reservoirs.

In the agricultural sector, a major citrus producer is exploring conduit hydropower to guarantee round-the-clock energy for juice production, benefiting surrounding communities. These examples show how small-scale ideas can evolve into industrial-scale solutions, significantly reducing water and energy footprints while creating jobs and socio-economic benefits. ESI

Cover photo:  olegganko©123rf.com