Yemen is set to be the first country in the world to run out of water, providing a taste of the conflict and mass movement of populations that may spread across the world if population growth outstrips natural resources. Government and experts agree that the capital, Sanaa, has about 10 years at current rates before its wells run dry but the city of two million continues to grow as people are forced to leave other areas because of water shortages. In Yemen, which is fighting three insurgencies, the battle lines of tribal wars have traditionally followed the lines of the wadis, desert valleys that become rivers when the rare rains fall. Amid one of the world's highest rates of population growth � 3.46% last year � the water shortage has become critical and is driving civil unrest. Water available across Yemen amounts to 100 to 200 cubic metres per person per year, far below the international water poverty line of 1,000 cubic metres. Groundwater reserves are being used faster than they can replenish themselves, especially in the Sanaa basin, where water once found 20 metres below the surface is now 200 metres deep, and despite the rainwater tanks on the roofs of most houses. In desperation some citizens have dug unlicensed wells, compounding the problem. In Taiz, in the south, tapwater is available only once every 45 days. In the mountainous Malhan district in the north, women and children climb a 1,500m mountain to collect water from a spring, often in the small hours to avoid long queues. Yemeni citizens have lived on scarce water supplies for thousands of years but the problem has been exacerbated by widespread production of the local drug of choice, qat, which consumes up to 40% of water. About 70% of Yemeni men chew the leaves each day, and bushy qat trees are often the only spots of green in the dry landscape. The Deputy Planning Minister, Hisham Sharaf, admitted: "We have a water shortage which reflects itself in fighting between the people� If we continue spending this much water on qat Sanaa has 10 to 15 years." The Government is considering a desalination plant for seawater, but this is an expensive solution and may come too late. The only other option is to cut down on the agriculture industry, importing even more food.