for human consumption, we are now using between 38% and 64% (Rogers, 1993). In the long run the amount of freshwater available to any country is nearly constant, although technological advances can increase the percentage of the water that is economically extractable. Recycling and reuse are two examples of technology that can increase total supplies (Asano, 1997; Willardson, et al., 1997; Yaron, 1997b). Of course, the supply of water per capita is decreasing. The world's population is estimated to be 5.930 billion in 1998 and projected to reach 8.039 billion and 9.367 billion by the years 2025 and 2050, respectively (World Resources, 1998). Correspondingly, fresh water availability for 1998, 2025, and 2050 are estimated to be 6918, 5103 and 4380 m<sup>3</sup> per person per year. These figures indicate that there is no foreseeable shortage in per capita availability.

Unfortunately, this fresh water is distributed very unevenly in space and time. In 1994, twentysix countries had insufficient renewable water supplies within their own territories to meet most needs of their current population. Population growth rates are relatively high in some of these countries, particularly in Africa and the Middle East (Gleick, 1993; Postel, 1994). If we examine some spatial water distributions in different regions we can see the disparity in per capita fresh water distribution by continent. Asia enjoys abundant annual fresh water per capita on averages (above 2400 m<sup>3</sup> per person in 2050). However, India seats at the lower end of the Asian water distribution with 1207 m<sup>3</sup> per person in 2050 and, within India, the state of Tamil Nadu will have only 490 m<sup>3</sup> per person in 2050, a sever water shortage by any standard. Some suggest that 1000 m<sup>3</sup> year-l per capita is an approximate minimum necessary level for an adequate quality of life in a moderately developed country or that 500 m<sup>3</sup> year 1 per capita is sufficient in semi-arid regions with extremely sophisticated water management (e.g., Israel - Gleick, 1993). At levels below 500 m3 year- per capita water availability becomes the primary constraint to life. This is therefore commonly used as the standard indicator of water scarcity (Seckler et al., 1998). If we examine the water situation in the Jordan River Basin we can see that for the region renewable fresh water per capita will be halved by 2050 given current population and consumption growth rates. A closer look reveals critical levels of water availability occurring within the next two decades for all countries, but Lebanon. Similar patterns can be seen in Africa's Maghreb and Northeastern sub-regions.

# _1.2_ **_Food Demand and Water_**

In addition to increasing levels of per capita demand for water consumption are water needs for agricultural purposes. Irrigated agriculture is practiced on 18% of the total arable land in the "wrld (approximately 237 million HA) and produces more than 33% of the total agricultural production. Of these irrigated areas, 71% are found in LDCs (60% in Asia alone). For most of human history irrigated lands expanded at a faster rate than did populations. However, irrigated land coverage peaked in 1978 and has fallen off nearly 6% since then (Postel, 1994). One reason for this trend is a decline in public irrigation investments as a result of debt loads, political resistance, rising real costs of irrigation development, and declining real prices for food (Rosegrant and Svendsen, 1993). As an illustration, World Bank lending for irrigation projects has fallen 50% between 1978 and 1992 (Wichelns, 1998). In addition, it has become increasingly expensive to supply irrigated water. Some examples of increasing costs of irrigation development can be found in Rosegrant and Svendsen (1993) and Sampath (1992). In India and 2