Yemen has the dubious distinction of being the first country that is expected to entirely run out of water, as the globe heats up. Its capital city Sana’a could be the first city to be emptied of its nearly half a million inhabitants by the catastrophic water scarcity that threatens billions by the the 2030s, with climate change. Except, for Sana’a, the end of water is expected in as soon as in six years, in 2017. So perhaps it is no surprise that it is a Yemeni who has had the winning idea for an international contest for “innovative ideas to improve the health and well-being in cities” Livable Cities Award, from Phillips, the US lighting company.
If there is one thing that makes a city unlivable it is no water.
Sabrina Faber, who has lived in Yemen for many years, and experienced water shortages herself, has won 75,000 Euros for her idea: a rainwater harvesting system incorporated into rooftops, based on the traditional designs she saw in the countryside.
Rooftop water cisterns are still in use in the countryside in Yemen, and throughout the country, flat roofs – with parapets – are common, making them seemingly ideal for this purpose. Hers would add water filtration to make the water safe to drink a crucial aspect of rainwater harvesting being innovated now by Israel.
But the fact that the idea has long been in use in the countryside, as it is in traditional buildings in other Mediterranean countries, but not in the city of Sana’a – despite near desperate straits suggests that houses in the city are not suitable for this system. Traditions that work don’t die out.
Maybe the city of Sana’a was settled earlier and its buildings are too ancient to support more weight on top? Certainly, the ones in her illustration in no way look able to support any extra weight by modern building code standards.
Yemen’s average annual precipitation varies greatly, with both droughts and floods common. Rainfall is unpredictable, from 500 mm (20 inches) 910 mm (36 inches) of rain a year, but many years there is none. When it comes, rain normally falls in the form of thunder-showers, heavy and short. But even that is not reliable. This combination of drought and infrequent heavy water loads is the worst-case scenario for antique building stock.