Driving around the residential hills of Dhahran, a city near Dammam, Saudi Arabia, one sees some lots left empty for rain water drainage. The lots are concave with a drain coming in toward the top. They usually seem empty of plants; just a place for the water to go away. 

These lots might be a good opportunity to plant some examples of desert-hardy food and medicinal trees. The lots would be taking advantage of the unwanted annual flood waters.

I wonder if a person could buy one of these lots to build a small house on and cultivate the rest.

As a side note, I notticed Dhahran is hilly--not 'pointy' mountains. Does this mean it was once forested?