Small reservoirs offer critical protection against drought but the construction, maintenance and management of these vital structures are often inadequate and the benefits they generate are rarely distributed equally.
Small reservoirs provide a lifeline for drought-prone communities across sub-Saharan Africa, making significant contributions to household income, food security and well-being. They allow communities to irrigate their crops during the driest months and water their livestock. They also provide water for essential domestic uses, including drinking, cooking, bathing and washing. But the benefits they provide are rarely distributed equally, tending to disadvantage women and youth, and there are concerns about their construction and maintenance which can lead to a range of negative outcomes, including siltation and poor water quality. Recent research suggests that some may even be hotspots for malaria transmission – posing a public health risk that threatens to undermine wider eradication efforts.
WLE-supported research aided by remote sensing data has helped broaden our understanding of these essential water structures: their number, size, characteristics and range. More in-depth studies and field assessments have also documented their many benefits as well as the challenges they face – helping to identify appropriate interventions that can secure and enhance their considerable value. Research has documented the effects of anthropogenic pressures, including land use changes such as crop production, which can increase soil erosion and siltation, and the application of chemical fertilizers and pesticides which damage aquatic health. The solution to these pressures, as suggested by the research, lies in diversifying the surrounding landscape, including the introduction of targeted soil and water conservation measures, reforesting degraded lands and strategically placing protected areas – or green zones – around reservoirs.
Studies have also highlighted the poor maintenance and management typical of small reservoirs, a challenge exacerbated by limited budgets and access to monitoring equipment which can detect, for instance, reservoir water levels and leakages. Researchers have further criticized a tendency to delegate responsibilities to water user associations which often prioritize small-scale irrigation and neglect other uses (and users). Power inequities are further reflected in the marginalization of women. Experience suggests that women will only benefit when local authorities and communities are sensitized to their rights, and women are themselves involved in the planning, implementation and management of small reservoirs.
Global evidence and data on small reservoirs is growing (for example see here) but it remains limited, complicating the wider application of WLE’s research and constraining the investments needed to construct, repair and maintain these vital structures. Legislation and regulations applicable to small reservoirs at the national level in most developing countries are also not well established, malpractices in planning and implementation are widespread and government support for the rehabilitation and maintenance of these structures is often not prioritized. Without defining responsibilities and establishing regulatory bodies, realizing the potential of small reservoirs becomes significantly more difficult.
Ensuring that small reservoirs help meet future water demand and support the resilience of rural landscapes and livelihoods requires urgent action to enhance regional capacities. Governments, contractors and engineers will need additional support to ensure the sound planning, construction and maintenance of small reservoirs. Crucially, capacity strengthening will also need to target local communities; their involvement in planning and design will promote a sense of ownership and encourage them to take on long-term responsibilities. Ultimately, community resilience and well-being will depend on more than access to the freshwater stored in reservoirs; they will also be contingent on access to key inputs such as efficiency-enhancing irrigation equipment, appropriate water management strategies and the strength of extension services.