The best place to get a look at the back or Lake Mead side of Hoover Dam from is from the Arizona side. There are a several places to park and each will give you a different vantage from which to photograph or just look at Hoover Dam. The overflow tunnels are located on the far right side of the image where Lake Mead edges against the mountains on the Nevada side. On the lower left side of the photo, the brown algae discolors the area where the water overflows. Note that these pictures were taken on April 3, 1999 - long before the current drought.

We are also able to see what the overflow system looks like when it is being used.

Algae and seaweed grows  on the surface of the metal locks and concrete.

We have been told that in the early 90's when Lake Mead was at capacity and the flow of the Colorado river was up, more  water ran over these gates and one could see some of the large carp which grow in Lake Mead go over the sides.

The size of theses tunnels can be appreciated when we see them compared to other, familiar objects. This picture tries to capture that.

The view is toward the tunnel showing the bridge that goes over to the Nevada side. We can see the trucks and how small they are in relation to the tunnel.

With the completion of the Bypass Project, interstate truck traffic will probably never pass over Hoover Dam again.
 

The water from any anticipated overflow is intended to flow through these huge tunnels from Lake Mead to the Colorado River almost 700 hundred feet below. The size of these tunnels is almost frightening. The dimensions are very large, over 60 feet for the tunnel, and the tunnel itself has no daylight at the end of it. One could imagine what a ride down that thing would be like.

The contrast of the smoothness and light color of the concrete against the rough and dark rock canyon walls is mitigated by how seamlessly the concrete fits to the rock surface.