Thought Leadership - Water-Energy-Food

The Nexus Approach To Sustainable Development

By Lani van Vuuren - Knowledge Dissemination Manager - WRC

South Africa needs to ensure that its natural resources remain in circulation for longer to alleviate food insecurity and deal with its challenges concerning water and energy. The water-energy-food (WEF) nexus strategy is gaining recognition globally as an intersectoral approach to resource management and sustainable development. Unlike integrated water resource management, which is water-centric in nature, the goal of the WEF nexus is to approach resource management more holistically by utilising a multi-centric philosophy.

Individually, food, energy and water are all vital for a sustainable future. However, these resources are also mutually connected or linked. So energy, for example, requires water, often in large volumes for fuel production, mining, hydropower and power plant cooling. On the other hand, energy is needed for pumping, treatment and distribution of water as well as the collection, treatment and safe discharge of wastewater. In turn, both energy and water resources are required to produce food. Water, energy, and food securities are inextricably linked, with the usage of resources within one sector influencing the use and availability in the adjacent sectors.

The Water Research Commission (WRC) with its research partners have been conducting studies on the WEF nexus for over a decade. Through this focused research, the Commission has not only been able to establish the nexus as an important framework for development in the country, but has been able to demonstrate successfully several initiatives aimed at improving sustainable development, especially at the local, community level. A couple of recent initiatives are highlighted here.

Ensuring Sustainable Development of Hydropower

Despite being a water-scarce country, South Africa has numerous river systems, more than 4 500 dams, thousands of weirs, irrigation networks comprising over 6 500 km of canals, hundreds of water and wastewater treatment plants and thousands of kilometres of water distribution networks with numerous pressure reducing locations. These structures offer the potential for power generation, ranging from pico (<20kW), micro (up to 100kW), or even mini (up to 1MW) schemes, which could possibly supply a school, clinic or even a whole community with electricity, among others.

To date, the lack of recognition of hydropower as a future contributor to renewable energy in South Africa has been due to the uncertainty pertaining to hydropower potential in th e country. To fill this knowledge gap, the WRC funded a project, undertaken by the University of Pretoria, to create So uth Africa’s first hydropower atlas (available here, http:// bit.ly/3o5qhl3). The aim of the project was to enhance the uptake of microhydro technology, making local stakeholders (private sector, financial sector, government entities etc.) aware of the opportunities that this technology brings, and the efforts required to get this technology successfully implemented in South Africa.

The South African Hydropower Atlas was developed on a Geographic Information System (GIS)-based platform to not only visualise the hydropower opportunities in South Africa, but to create a database where data related to hydropower quantification can be shared. This allows for private entities, water utilities, developers and general users of the atlas to share available data and aid in the identification of additio nal sites or to improve the reliability of data already included in the atlas.

The atlas includes several data layers, including existing hydropower plants, potential hydropower sites, South African electrical infrastructure, hydrological and rainfall layers, to name a few. These layers aim to enhance the visualisation of South African water infrastructure and rivers and the hydropower that exist within.

The KwaMadiba small-scale hydropower plant in Eastern Cape

Harvesting Rainwater and Biogas

In the villages of Krwakrwa and Upper Ncera, in the foothills of the Amathole mountains in the Eastern Cape, the WRC with the Agricultural Research Council (ARC), the provincial Department of Rural Development and Agrarian Reform (DRDAR), the Fort Cox College of Agriculture and Forestry, and the University of Fort Hare undertook a six-year project to assess rainwater harvesting and conservation practices for production of food as well as renewable energy in the form of biogas.

In these villages, as with many in South Africa, few households have a monthly income exceeding R2 000, so poverty and food insecurity is rife. Most households are headed by elderly women, some of whom tend household gardens. Electricity is expensive so it is typically only used for lighting, while c ooking and heating is done with firewood collected from the veld. This not only results in deforestation, but is a health and safety hazard through exposure to smoke and the risk of accidental burns and house fires.

Within the villages, demonstration plots were established to show how water harvesting, vegetable crops, cow dung and bioenergy can be integrated. Thanks to additional funding from DRDAR, 14 biodigesters – seven in each village – could be installed at households that had their own water storage tanks as well as ready access to cow dung. Project team members helped the households to construct in-field rainwater ha rvesting (IRWH) basins in their gardens and provided them with seeds and seedlings.

With the IRWH technique the households are now able to produce a variety of vegetable crops throughout the year, as they can use water from the tanks for supplemental irrigation during the dry season. Bioslurry effluent from the biodigesters is used as a fertiliser source while the biogas is piped into householders’ kitchens, providing a valuable energy supply.

Farmers' days were held to allow the selected beneficiaries to display the fruits of their labour and share their knowledge and challenges with stakeholders and other villagers.

Biodigesters were installed at 14 households that already had water storage tanks and access to cattle nearby, since the biodigesters needed to be 'fed' with water and cow dung at least every five days

The WRC projects under the WEF nexus theme raise awareness about the interlinkages between water, energy and food, and create a platform for discussion of practical solutions that include the negotiation of synergies and trade – offs linked to the WEF nexus issues. The WEF nexus presents an opportunity to promote integrated planning in a sustainable manner. The WRC will continue to drive research, development and innovation linked to knowledge generation on the WEF nexus.