all of the water from the colorado river (grand canyon) is used. it used to flow into the gulf of baja but it now stops about 60 miles short. if you put up a new dam it would take years to fill up (lake mead took 6 years to hit 1,200 feet). during that time, all of the cities and agricultural that relies on that water would fail. there would be mass starvation in the u.s. and cities with populations of 2 million+ each would turn into ghost towns. since the hoover dam/lake mead was created the u.s. population has quadrupled. we simply can't afford to be without that water.
United States