Hoover Dam is one of the major landmarks in Dam construction. It's hard to believe that the Coloridao river you see here, flowing out of the lake, doesn't reach the Gulf of California anymore because there are too many dams tapping water to the desert areas around it to grow vegetables. The last major barrier is the Morelos dam near the border of USA and Mexico, tapping the water for the Mexicali valley to grow cucumbers and onions on the irrigated fields and to supply the vegetable-neady areas of California and Mexico. In march 2014, there was an initiative between the responsible countries to release a huge amount of water to rejuvenile the dry river delta of the Colorado. Nevertheless, most of the time, you will not see any Colorado river water flowing into the Gulf of California.
Source: NewScientist, 15 March 2014, p.8