Managing irrigation water for safe domestic use

Managing irrigation water for safe domestic use

Rural communities in most developing countries often obtain their drinking water from deep tube wells and hand-pumps that exploit groundwater, which is most often free from harmful bacteria and parasites. However, in large areas of South Asia, the Middle East and North Africa (MENA), groundwater is not always an option because of high levels of arsenic, fluoride, iron or salt. In such cases, irrigation water is often the only water available for multiple uses such as drinking, bathing and washing. Irrigation water that seeps from unlined canals, reservoirs and fields percolates through the soil layer and may form shallow pockets of groundwater. These provide a clean source of drinking water in areas where groundwater is otherwise not potable. This important indirect use is often not recognized by those authorities responsible for irrigation planning. Interventions designed to 'save' water, such as canal lining, can leave village wells high and dry. At the same time, the increased availability of water from irrigation canals can help to enhance hygiene and thus improve health. In many places, access to water has been facilitated by steps in the canal bank, or by special water releases. IWMI, in an effort to put this issue on the map, looked at the ways irrigation water can be made safer for domestic uses. A series of studies in Pakistan, Sri Lanka and Morocco examined the links between irrigation management, the domestic use of irrigation water and human health. Key research questions How important are nonagricultural uses of irrigation water for rural/agricultural development? How can the needs of nonagricultural users of irrigation water be incorporated into the management and design of irrigation systems? How can irrigation water be made safer for drinking, bathing and washing? What is the impact of irrigation management on the availability of fresh groundwater? What are the positive and negative health impacts of domestic use of irrigation water? How can the health hazards of this practice, such as exposure to the parasite which causes schistosomiasis (carried by water snails) when washing clothes or bathing in irrigation canals, be reduced?