This paper highlights the difficult choices that must be made as mounting pressure from the world’s growing population for more food could lead to greater water consumption and increasing environmental degradation. Globally, agriculture uses between 70 to 90% of developed water supplies and the livelihoods of 70% of the world’s poor depend largely on farming. Despite the benefits, large-scale irrigation systems have led to pollution in rivers and the drying up of wetlands: at least 30% of the world’s river flows need to be used to maintain the condition of freshwater ecosystems worldwide.The paper argues that there is less water available for the competing demands for water (water to feed people, water to reduce poverty and water to sustain natural ecosystems) because of increasing water demands by cities and industries. It identifies a number of ways of resolving this dilemma: <B>Improved water productivity:</B> this might be achieved through improved crop varieties, combined with better tillage methods and more precise drip or micro irrigation. Drought resistant seeds, water harvesting schemes and small plot technologies such as manually operated treadle pumps have the potential to boost yields by 100% in many areas of sub- Saharan Africa where most farmers depend on rain fed agriculture. An improvement of water productivity by 40% over the next twenty five years would be reduce the global need for extra water for irrigation to zero. <B>Influencing peoples’ diets:</B> Western diets based on meat from grain fed cattle account for as much as 5,000 liters per capita per day while vegetarian diets deplete less than half as much water. With prevailing land and water management practices, a balanced diet requires 3287 liters of water per day compared to the 50 used for an average household’s domestic needs. <B>Increasing the trade of ‘virtual water’: </B>this trade in food from water abundant countries to water scarce ones is another option to be considered, but it is questionable whether low income countries will be able to afford ‘virtual water’ and there may be negative consequences for poor farmers. <B>Increasing the use of urban wastewater for irrigation: </B> up to one-tenth of the world’s population eats food produced using wastewater from towns and cities. Using wastewater and saline water for irrigation may improve the quality of water available for ecosystems in basins where there is still some outflow<B>Reforming agricultural policy: </B> agricultural subsidies in the west are a major factor in keeping prices low for agricultural producers in developing countries. However, decisions on diet and trade tend not to factor in water issues directly. While diet transitions in developing countries increase water demands, and some farm practices can be changed, influencing people's diets may not be a practical means of addressing water scarcity across the world. Global trade flows similarly resist influence, as economic and political motivations tend to override environmental ones.Of these options, increasing water productivity and the upgrading of rain-fed systems have the most potential to improve food security and reduce poverty at the lowest environmental cost. The paper finds that gains from increased irrigation efficiency are a lot less than imagined.This draft version of the report was prepared for a World Water Week 2004 event held in Stockholm

With the increasing population and accelerated urbanization, demands for water are rising for different sectors around the world, including in South Asia. Integrated water resource management (IWRM) offers a promising potential to address multifaceted water demands. This study therefore aimed to address this issue by (i) reviewing key issues related to water, land, and food in South Asian countries, (ii) exploring the prevalent irrigation management strategies in those countries, and (iii) examining the IWRM situation based on a Nepalese case study, and it proposes some options to support effective implementation of IWRM. South Asia, the home to 24% of the world's population with only 15% and 7% of the world's arable and permanent crop land and water resources, respectively, is the worst-affected region in the world from undernourishment. Surface irrigation is the dominant irrigation application method in the region, which incurs high water losses due to the lack of flexible water control structures in canal networks. The Nepalese case study revealed a lack of clear institutional arrangements to implement IWRM and disparate and conflicting views about IWRM. Creation and strengthening of basin-level water user organizations, technological improvements, and awareness-raising activities are some potential ways forward to implement IWRM.

We explore processes that enable effective policies and practices for managing the links between water, energy, and food. Three case studies are assessed at different scales in the Mekong River basin, Sri Lanka and Zimbabwe. We find that there are considerable opportunities for improving outcomes for sustainable development by finding solutions that accommodate multiple objectives in the nexus. These include making data more publicly available, commissioning independent experts to advise on contested issues, engaging under-represented stakeholders in decision-making, sharing benefits, exploring different perspectives in forums where alternative development options can be tested and engaging decision-makers at different scales.

We explore processes that enable effective policies and practices for managing the links between water, energy, and food. Three case studies are assessed at different scales in the Mekong River basin, Sri Lanka and Zimbabwe. We find that there are considerable opportunities for improving outcomes for sustainable development by finding solutions that accommodate multiple objectives in the nexus. These include making data more publicly available, commissioning independent experts to advise on contested issues, engaging under-represented stakeholders in decision-making, sharing benefits, exploring different perspectives in forums where alternative development options can be tested and engaging decision-makers at different scales.

Urbanisation will be one of the 21st century's most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. >50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62–93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies.

Urbanisation will be one of the 21st century's most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. N50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62–93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies.

Contributed papers presented at the conference organized by International Water Management Institute, Irrigation Dept., Dept. of Agriculture, and Hector Kobbekaduwa Agrarian Research and Training Institute.