Land subsistence in the American southwest

A) The causes of land subsistence in the American Southwest, is to to them being in the desert, using to much water and it is so to the growing population in the area which causes this to happen. 

B) Some impacts that can be caused by land subsistence is that it can change the elevation of streams, canals and drains. It can also damage bridges, roads, rail roads and storm drains also damaging buildings. On example is 

C) One way to percent this could be to limit the amount of water that is being used, recycling the water and maybe creating a lake.