Make an underground ducts for the waste water . Create a stone and sand pit around structures , let that water be part of the construction . Let things be connected like an underground streams . Over a period of time they will have a water table and I am sure trees will grow . This plan is possible only during the construction stage off a project . There is more to this plan of how to channelized water and the important human waste into fertilizer for the tres . I am sure this can be done . Qatar is spreading by leaps and bound . If planned properly for a green Qatar then it is possible .
I know some one will like this thought and give a technical trial run .
Do let me know If I lost the plot .
Good wishes always
Hope to see a green Qatar .