Sustaining water: an update. Revised data for the Population Action International report Sustaining Water: Population and the Future of Renewable Water Supplies.

Data are presented on the annual per capita availability of renewable fresh water in 149 countries for the years 1955 and 1990 and on the annual per capita projected availability of renewable fresh water for UN low medium and high population projections in these countries for the years 2025 and 2050. Figures are given for total annual renewable fresh water by country in cubic kilometers population in thousands and per capita water availability in cubic meters. Renewable water is that which falls on a countrys territory or flows in from neighboring countries and is all the water a country can use sustainably. These updated figures reveal that if the UNs medium population projections become reality by the middle of the coming century 4.4 billion of the nearly 10 billion people on the planet will live in 58 countries experiencing either water scarcity or water stress. If the high projection occurs 7.7 billion people (65% of the worlds population) will live in 66 water-short nations. The low projection would see 3.5 billion people (44%) living in 51 water-short countries out of a total population of 7.9 billion.