Water scarcity in the Luvuvhu Catchment, Vhembe Biosphere Reserve
As part of the BE Resilient South Africa program, UNESCO worked toward sustainable water and ecosystem management with CRIDA. The Luvuvhu catchment, dryland experiencing increasing water stress, functioned as a pilot from which findings and tools can be up-scaled and replicated.
Контекст
The Luvuvhu River, a perennial watercourse in the Vhembe Biosphere Reserve, located in the northeast of South Africa. Its diverse catchment faces water management challenges, with significant dams regulating flow. Threats like land degradation, invasive species, and poor infrastructure impact water quality and ecosystem health.
Действия
In the first phase, CRIDA Step 1, the project focus and scope were developed through stakeholder workshops and community engagement. Water scarcity in the Luvuvhu River Catchment was selected as the focus of this project. In the second phase, CRIDA Step 1 and 2, tools and models were developed to evaluate the catchment's vulnerability to climate change. The results suggest that the catchment will become warmer and drier under climate change.
The third phase of the project, entailed CRIDA Step 3 and 4, formulating adaptation actions and evaluating the adaptation pathways. Three types of adaptation actions were evaluated: nature-based solutions (alien vegetation removal, grassland/forest restoration, and soil modification), traditional actions (increasing dam storage and limiting groundwater extraction), and community-based interventions suggested by locals to enhance resilience to climate change. The nature-based solutions were put into 5 adaptation pathways which were subsequently quantitatively and qualitatively evaluated (respectively through modelling and a scorecard).
Outcomes
The stress test results suggest that the catchment will become warmer and drier under climate change, with a projected 20% decrease in streamflow relative to historic flows in the next 20 years. In response, five adaptation pathways were developed through stakeholder workshops in collaboration with the Vhembe Biosphere Reserve, focusing on nature-based solutions. These pathways propose a range of strategies to mitigate water scarcity over time, offering flexibility for decision-makers.
The core actions include removing alien invasive species and replacing them with grasslands or forests, as well as soil amendments to increase water infiltration. These actions are supported by stakeholders and provide co-benefits, such as erosion control, which reduces sedimentation in reservoirs and prolongs the lifespan of critical water infrastructure during floods and droughts.
The evaluation stresses the importance of timing, sequencing, and location for the effectiveness of adaptation actions. Ongoing development could limit future options, so managing development is crucial to prevent worsening water scarcity. Uncontrolled groundwater extraction also needs addressing to avoid resource depletion and inequitable water access.
Overall, the study highlights that ecosystem-based approaches can improve the catchment's resilience to climate change, offering sustainable, long-term solutions to water scarcity while balancing environmental, social, and economic needs.