Past Peak Water in YemenYemen’s capital, Sana’a, is the fastest-growing capital in the world but experts predict it will run out of economically viable water by 2017. Its water supply catchment 20 km NW, Wadi Dahr, is also used to grow the trees that provide qat leaves, used as a mild narcotic by many Yemeni men. Together, the Sana’a population growing at 7% p.a. and the irrigation of qat, ensure that Wadi Dahr’s aquifer is being depleted at four times the rate of the annual rainfall replenishment. And it is not only Sana’a; 19 of 21 main aquifers in Yemen are depleting as a result of drought and increasing demand. Yemen’s national water resource provides about 200 m3 per person p.a. – compare New Zealand’s 100 000 m3 p.p. p.a. or the international ‘water poverty’ figure of 1000 m3 p.p. p.a. The problem is so serious that authorities have considered moving the capital, or pumping from a desalination plant on the coast, with a 2000 m lift. So far no solution is acceptable. And yes, ceasing to grow irrigated qat has been considered but also presents problems as it provides much-needed employment in a country where half the workforce earns less than US$2 per day. Yemen is also expected to run out of oil about 2017, which currently provides three quarters of government revenue. A sad irony is that state-subsidised diesel is used to pump water from aquifers, so the government is estimated to have spent about US$700 million depleting its own national water resource.