Of course that was 'long ago' in climate terms. Now the goal posts have moved, because of Qat and not population no less...
Among many problem sites, Sana'a, Yemen's capital, has doubled its population on average every six years since 1972 and now stands at 900,000 people. The aquifer on which the city depends is falling by six meters (20 feet) a year, and may be exhausted by 2010, according to the World Bank.(link)
According to water experts, more than four thousand wells in Sana’a have been specifically dug for the sole purpose of irrigating Qat fields, which has led to a lower water levels of an average of three to six meters a year. Experts warn of drought within the Sana’a area by 2015.(link)So in a few years (4) we'll have more experts to tell us why Yemen's capital is running out of water, if it indeed ever does.