A Regional Planning Response to Water Scarce Cities: The Case of Monterrey, Mexico

In dealing with the increasingly arid conditions, and the scarcity of water in urban metropolises it is not sufficient to copy solutions that were useful in the past, when the problems were fundamentally different. The radical changes in climate conditions require a novel approach to keeping and creating water in those urban regions. In this chapter the regional planning opportunities for realizing this are presented. The first strategy is to think at the watershed level of the entire river basin and apply the three-step strategy. First, capture the water and let it infiltrate in the soil. Secondly, the water needs to be retained in basins to keep it as long as possible in the system. The final step is to create space for the water in urban contexts where the discharge of the water is slowed down. A second strategy beholds the case of water being absent. In this case, a more radical planning approach is proposed to create rain (water). Using the biotic pump principle of letting forests emerge and expand, to create their own rain, the rainfall and humidity in a region can substantially increase. Both strategies shall be applied in coherence, so the water supply of large urban conurbations can be kept up to level.