Improving irrigation management

Irrigation system management can be improved to provide more reliable water supply to farmers through storage and improved operation of reservoirs, better distribution of water with improved control structures as well as more responsive management.More reliable water supply allows farmers to invest in better on-farm water management such as better land leveling, zero tillage, or pressure irrigation. Improved management usually requires improved institutions as well as improved technologies.Governments rarely manage to operate and maintain irrigation systems successfully on their own. Farmer participation increases success rates. Schemes have to be financially self-sufficient on operation and maintenance and farmers can, and do, pay for well-performing systems.

Multiple use systems: single systems for domestic use, agriculture, aquaculture, agroforestry and livestock.

Rural people often do not distinguish between water for domestic or livelihood purposes. However,water projects and water experts usually still focus on a single purpose. Increased value can be captured by designing, planning and managing projects that enable multiple uses in an
integrated manner.

Enhancing the safe and productive use of wastewater in irrigated agriculture

Growing water demands of rapidly expanding urban areas also create the opportunity to re-use the equally growing wastewater flows. Making an asset out of wastewater for peri-urban small-scale farmers may make sanitation affordable for poor urban dwellers.Development of appropriate treatment systems to make the waste water biologically safe,while keeping the nutrients that replace fertilizer for farmers, is the challenge. Potential benefits include improved health in urban slums, livelihoods for peri-urban farmers, improved nutrition (vegetables) for the urban poor, and reduced pollution.

Wastewater is being increasingly used in
agriculture and can be a valuable asset
for productive use if it can be properly
treated
Photograph by Sanjini de Silva IWMI

Adapting farming practices to increased water scarcity

When water is relatively abundant, and its cost to farmers is negligible, farmers are not motivated to conserve water. As water moves out of agriculture to cities, and population densities increase in rural areas, the scarcity and value of water increases. Farmers can, and will, respond to increased scarcity, or higher cost such as pumping cost at greater depth at realistic energy prices, by using water more effectively.

WP-field: The amount of crop output in physical terms (crop yield in kilogram) or monetary terms (crop yield times its price in financial or economic terms) divided by the amount of water consumed (evaporated from the soil or transpired by the plant, the evapotranspiration) - in other words, the crop per drop.

WP-basin: At the basin level, water productivity needs to be understood in the widest possible sense, including crop, livestock and fishery yields, ecosystem services as well as social impacts such as on health, together with the systems of resource governance that assure an equitable distribution of these benefits.

Increasing water productivity is therefore equivalent to obtaining more value from each drop of water.

Improving water productivity by 40% on rainfed and irrigated lands could reduce the need for additional withdrawals for irrigation over the next 25 years to zero.

Typical water productivity figures for staple cereal crops (rice and wheat):

Typical low performing irrigation system - 0.5 kg per cubic meter
State-of-the-art irrigation system in Asia - 2.0 kg per cubic meter
Rainfed systems in Sub-Saharan Africa - 0.2 kg per cubic meter
Rainfed systems in Europe/North-America - 2.0kg per cubic meter