We need more than urban planning although that is one important component.  Technology must be looked at to change the way things are done. Things like self-driving cars will reduce the need for new roads.  Both sort and long distance must be added.  Rural area need better internet service and other services to make living there easier. Adding renewable energy generation and transportation that can use nonpolluting energy will significantly reduce pollution.
Closed loop food generation like hydroponics and algae bioreactors need to be part of the water shortage problem.  We already have a deficit using current agricultural practices and variations that may small improvements will not be enough to deal with increasing population and increasing warming. Such a program helps keep people in rural areas which in turn reduces the problems of housing and congestion in urban areas.