A once-in-a-lifetime FLASH FLOOD has hit a small SAHARAN town leaving two-metre-deep water running through the centre. Residents had to be rescued from the deep flood waters after the Sahara, which is the DRIEST place on Earth, was battered by torrential rain in a freak thunderstorm yesterday (Sun). Incredible photos show how sudden downpours have caused severe flooding in the small Saharan desert town of Ain Sefra in northwestern Algeria. Cars can be seen deep underwater after the rain flooded the town?s city centre, leaving tonnes of sand behind. Residents have had to dig their way out of their homes after more than three feet of sand was left behind by the flood waters. The Sahara usually gets little to no rain, so locals have been left stunned by this ultra rare phenomenon. Last week a huge lake suddenly appeared nearby in the dry desert following another heavy rainstorm. Local Karim Bouchetata said: ?It was a small pond and it was about to dry up because of the drought, so we were stunned to see a lake appear in the middle of the sand dunes in the summer.? Ain Sefra - known as ?The Gateway to the Desert? - is around 1000 metres above sea level and surrounded by the Atlas Mountains. The Sahara Desert covers most of Northern Africa and it has gone through shifts in temperature and moisture over the past few hundred thousand years. Although the Sahara is very dry today, it is expected to become green again in about 15000 years. Pictured: gv,general view,Image: 906051438, License: Rights-managed, Restrictions: -GBR, Model Release: no, Pictured: gv,general view