Sanaa is at least 2,500 years old. It claims to be the world's oldest inhabited city. It is also the capital of Yemen in Middle East.
Its population of 1.74 millions is said to be living on living on borrowed time. For in a country where water is a scarce commodity, whatever water is available is soaked up by khat.
Everywhere one turns in Yemen, one can find men with cheeks bulging bizarrely as they get their fix. It is a shrub whose leaves, when you chew them, can induce mild euphoria, excitement, hallucinations and even constipation.
It is increasingly popular in the country. While a few years ago men would spend a couple of hours a day on their habit, many now chew happily away for seven or eight hours.
Within the last five years or so khat use has become much more accepted among women. Of the country's scarce water, 40% goes on irrigating khat - and khat cultivation is increasing by 10% to 15% a year.
Growing khat earns a Yemeni farmer 20 times as much as growing potatoes. In a country where almost half the people live on hardly one US dollar a day, khat income is eminently welcome. Also in a situation of grinding poverty khat-chewing is one of the few affordable sources of pleasure.
And it is the residents of Sana who would be paying the price for it all. They would have to move out. For it is affected the most by the water crisis.
As governments don't care or cannot do much, the water crisis is assuming menacing proportions. Many say total depletion of underground reserves is nearing.
The country imports most of its food, largely because it has too little water to feed itself. Yemenis have about one-fiftieth as much water per head as the world average.
The minister for water and the environment, Dr Abdulrahman al-Eryani, is an agricultural engineer.
'The Sanaa basin is using water 10 times faster than Nature is replenishing it,' he said.
'And before long there won't even be enough to drink. I am not an optimist. I think many of the city's people will simply have to move away, ' he says almost shrugging his shoulders. But where will they go?
'The solution I am proposing is a very clear policy - a voluntary one - of reallocating people from here down to the Red Sea coast. We could use renewable energy there to desalinate sea water. And it would be cheaper than trying to provide enough water to Sanaa,' the minister explained.
Anyway this is not the first time that Yemenis would be moving to avoid disaster. It's happened many times in the last few thousand years, when Nature allowed the population to increase rapidly, he adds.
One of the ancient Arabic names of Sanaa translates as The Protected City. As a journalist remarked, 'It looks as though the protection is running out. '