How shared resources and a community-focused water management system could be the solution to a land ravaged by climate crisis

The Limpopo River Basin is the driest it has been for 35 years. It winds its way through four countries – Botswana, Mozambique, South Africa, and Zimbabwe. Underneath the arid, burnt-yellow landscape, are groundwater-holding aquifers. They too, are at risk of running low during droughts, but better management of the groundwater supplies could transform residents’ lives. Groundwater is the foundation of water security and climate resilience across Africa. It’s plentiful, and yet four in ten people across the continent lack access to good, clean drinking water. Just one percent of farmland is irrigated using groundwater, and drought is a serious problem for many countries.

Background

The Limpopo Basin’s population is increasing. In 2012, the population was around 18 million, and it is estimated to grow to 20 million by 2040. This population increase is putting pressure on the region’s natural resources. In addition, major cities including Johannesburg, Pretoria, and Gaborone lie upstream, which adds to the pressure on water supply, and causes scarcity and pollution downstream.

Source: http://population.city/south-africa/adm/limpopo/

The Limpopo Basin has experienced severe droughts in the past, as boreholes and rivers dry up. Reduced rainfall led to declaring the Limpopo Province in South Africa a disaster area in 2016. Crop failure and economic hardship was widespread. It is clear that to avoid serious drought impacts again, the river basin needs to be resilient and able to absorb shocks.

Groundwater could be the answer, but it is not always easily accessible. Sometimes it doesn’t replenish quickly enough, it is deep below the ground surface, and other times, especially when aquifers are close to the sea, they might become saline. The transboundary Ramotswa Aquifer, shared between Botswana and South Africa, is ‘user-friendly’, in the sense that it provides ample groundwater when you insert boreholes, it is relatively shallow and it’s located close to where people live. Hence, the project aimed to improve people’s access to clean water from this aquifer, while also addressing farmers’ hardship in getting groundwater for their crops outside of the Ramotswa Aquifer area. IWMI is a leading partner in the RAMOTSWA project.

The challenge

Before IWMI and their partners took on the project, there was limited knowledge around the role the Ramotswa Aquifer, and other transboundary aquifers, could play in supporting resilience in the basin. Also, it was unclear how to manage such ‘shared’ or transboundary resources, as this was never attempted before. The key aim of the project was to jointly understand the aquifer and the water challenges in the area, while identifying possible solutions, both from a technical and management perspective, so that these resources could help underpin resilience long into the future – a future with a more erratic climate.

Implementing a solution 

Kicking off in 2015, the RAMOTSWA project used both innovative and traditional techniques to better understand the aquifer. Some of these included the use of ‘airborne geophysics’, computer models and scenario analysis of various solutions that could enhance the secure access to sufficient and clean groundwater from the aquifer. Fundamental data were collated with the help of local and national partners to ‘stitch’ the knowledge together across the border, which had never been done before. Data were then shared between the countries and through joint learning the issues around groundwater and its use and management were ‘unearthed’ and discussed. This led to consensus on key development challenges and priorities in terms of investments that could enhance water security in the border region.

An integrated hydrological computer model was then created, in order to understand the underground processes of water flow in the Ramotswa area. This also helped the researchers understand the interactions between the aquifer and the river running along the border between Botswana and South Africa, as well as the predominant groundwater flow direction between the two countries.

The model, as part of a larger transboundary diagnostic, allowed the team to develop potential scenarios for groundwater management, e.g. how to augment the replenishment of groundwater through managed aquifer recharge – meaning how to put more water underground for future storage and use, e.g. from flood waters. The assessments led to a joint strategic action plan. This supported local and national policy-makers in identifying priority investments for the area.

The joint strategic action plan, developed as a cooperative process between the countries, identified priority actions, each belonging to one of the following categories:

• Managing water for sustainable use, availability and access
• Enhancing institutions and capacity
• Expanding research and knowledge

The joint strategic action plan emphasized the need for cooperation around effective data management and sharing between the countries. This meant developing a joint data management system, the Ramotswa Information Management System (RIMS), containing data collected with support from national governments and universities. It aligns data collection and management systems, ensuring data compatibility, and implementing data sharing procedures between the different transboundary actors. The purpose of the database is to help improve decision making on how best to manage the aquifer.

The joint strategic action plan also highlighted a need for strengthening existing transboundary institutions – principally LIMCOM – to incorporate, for the first time, the management of transboundary aquifers into their portfolio.

To formalize this significant step, LIMCOM established an international committee between the four countries for the management of groundwater resources in 2019, the LIMCOM Groundwater Committee. This committee focuses on establishing best practices for transboundary aquifer governance in the basin and more broadly in the region. Out of 12 international river basin organizations in the SADC region, LIMCOM is the second to establish a dedicated institutional mechanism to oversee shared aquifer management.

The next step of the project was to support agricultural water management. The researchers adapted a set of tools, which local farmers could use to optimize their groundwater use for irrigation. Through simple soil moisture probes and nutrient measurements, farmers learned how they could save up to 40% of water, 30% of energy (for pumping groundwater) and 80% of fertilizers on their crops and even enhancing their crop production. This creates great savings and additional incomes for the farmers.

Finally, in 2020, IWMI piloted a transboundary groundwater monitoring system in the Tuli Karoo Aquifer area to gauge groundwater levels.

The aquifer underlies an arid triangle of land in the upper Limpopo Basin, shared between Botswana, South Africa and Zimbabwe. Irrigation from both ground and surface water is key to the production of cereals, legumes, and vegetables as well as high-value crops and livestock.

Yet, in most years, water shortage results in farmers not fully cultivating all irrigable land in their schemes. Four existing wells in strategic locations were equipped with automatic data loggers and connected to a telemetry system and a visualization platform to monitor and transmit data on water levels, temperatures and electrical conductivity in real time.

This allowed farmers to gauge their water consumption and their prospects for short and long-term irrigation. The pilot is under expansion to cover 58 strategic locations in total.

After years of work, our project has made a big difference:

• A project is deemed a success by the sheer number of people it helps, the valuable relationships it builds, and the essential data and information it generates. The transboundary RAMOTSWA project achieved all three, and more.