Water Harvesting - Guidelines to Good Practice
Water harvesting has been practiced successfully for millennia in parts of the world – and some recent interventions have also had significant local impact. Yet water harvesting’s potential remains largely unknown, unacknowledged and unappreciated. It is time to scale-up the ‘good practices’ of water harvesting that have survived or emerged from new experience, after decades of almost exclusive focus on mastering fresh water flows in rivers and lakes through investments in irrigation infrastructure. Water harvesting offers under-exploited opportunities for the predominantly rainfed farming systems of the drylands in the developing world. It works best in precisely those areas where rural poverty is worst. When practiced well, its impact is to simultaneously reduce hunger and alleviate poverty, as well as to improve the resilience of the environment. The principle is simple: capture potentially damaging rainfall runoff and translate this into plant growth or water supply. This makes clear sense where rainfall is limited, uneven or unreliable with pronounced dry spells. Yet despite these rainfall limitations, runoff occurs due to high intensity showers and the low water holding capacity of fields, pastures, and forests. And with the impacts of climate change already with us, here is an approach to better use a local resource for livelihood sustenance. These practical guidelines offer a menu of technologies that can form part of an overall adaptation strategy for rural people: farmers and nomads, women and men. Rainwater harvesting technologies presented in these guidelines are flexible and if needed can be adjusted to the local context while being embedded into institutional frameworks. The International Fund for Agricultural Development (IFAD) and the Swiss Agency for Development and Cooperation (SDC) have come together to present water harvesting in a way that makes good practice both understandable and accessible. These guidelines are intended to inform decisionmakers and donors, but are mainly geared to be of direct use to practitioners in the field, all the way up to watershed and river basin planners. A wide span of technologies are covered: these range from large-scale floodwater spreading that make alluvial plains cultivable, to systems that boost crop, fodder and tree production in small farms, as well as practices that collect and store water from household compounds. There is a hidden wealth of knowledge about these water harvesting technologies, and the settings in which they tend to perform best. This is the first time this knowledge has been uncovered, collated and made available in such an organized, illustrated and informative way – linking technologies to the knowledge networks that will serve the intended users of these practical guidelines to better understand and implement their choices.