Food service directors and dietitians in many parts of the United States are having to cope with rationed water and use filtered water. Throughout the country, theEnvironmental Protection Agency reports that one third of our drinking water supply is contaminated. The water problem might well become more serious than the energy crisis. An in depth report on what has happened and what should be known about one of the nation's most urgent, but least accepted, problems is presented. Illustrative photographs and numerous tables accompany the report.

Data on the volumes of renewable water resources and the specific dependable water supply are given for countries with the least water resources available. Data on the current volumes of water resources withdrawal, irrigated land area, and the population size in largest world countries are given. Measures taken by various countries with the aim to enhance water resources availability for agriculture are described. The further increase in the area of arable and irrigated lands, with the current technologies still in use in the agriculture, is shown to be inadmissible. The role of reclamation in the ensuring of food safety in Russia is demonstrated.

This brochure has been developed for the Water for Food and Ecosystems programme on behalf of the 3rd World Water Forum

To meet the food demand of a growing global population, agricultural production will have to more than double in this century. Agricultural land expansion combined with yield increases will therefore be required. This thesis investigates whether enough water resources will be available to sustain the future food production. Using a global scale hydrology and crop growth model, the combined effect of climate change and socio economic changes on water scarcity and food production were quantified. The first thing to explore was where water for agriculture is currently extracted. Reservoirs behind large dams are found to be very important for agriculture and contribute around 18% of the total irrigation water today. It is shown however that with current reservoir capacities and irrigation efficiencies, not enough water can be supplied to sustain an increased food production. Irrigation water shortage can lead to a loss of 20% of the irrigated crop production globally, but with important regional differences. Regions particularly at risk include basins in Southern Africa and South Asia, where production losses on irrigated cropland can become over 50%. This means that unless major investments are made towards improving irrigation efficiency and increasing storage capacity, water shortage will put a serious constraint on future food production.

Water scarcity is already a reality. More food will be required for a growing and wealthier and urbanized population that will put more pressure on water resources. With several water-related limits reached or breached - groundwater decline, shrinking rivers and threatened fisheries - we must ask, Will there be enough water to grow enough food? It is possible to produce the food needed, but if present practices continue it is not probable that we will solve the many poverty and environmental challenges confronting us. To share a scarce resource and to limit environmental damage in the face of climate change, it is imperative to limit future water use. Important pathways to growing enough food with limited water are to increase productivity of water in irrigated and rainfed areas, improve water management in low-yielding rainfed areas, and to consider our own food consumption patterns. In pockets of poverty in sub-Saharan Africa and Asia, expanding access to water through a range of water management solutions holds the key to food security and poverty reduction. For sustainable water use, water managers must consider agriculture as an ecosystem and how other ecosystem services are impacted through water. These actions will require serious changes in how we think about water and food, and how we govern water and land resources.

Water and food are major environmental transmission routes for Cryptosporidium, but our ability to identify the spectrum of oocyst contributions in current performance-based methods is limited. Determining risks in water and foodstuffs, and the importance of zoonotic transmission, requires the use of molecular methods, which add value to performance-based morphologic methods. Multi-locus approaches increase the accuracy of identification, as many signatures detected in water originate from species/genotypes that are not infectious to humans. Method optimisation is necessary for detecting small numbers of oocysts in environmental samples consistently, and further work is required to (i) optimise IMS recovery efficiency, (ii) quality assure performance-based methods, (iii) maximise DNA extraction and purification, (iv) adopt standardised and validated loci and primers, (v) determine the species and subspecies range in samples containing mixtures, and standardising storage and transport matrices for validating genetic loci, primer sets and DNA sequences.