

How to Use the Images


Inquiry Question

Historical Context




Photo 1 and 2
Photo 3
Photo 4
Photo 5
Photo 6 and 7


Table of

Visual Evidence

Illustration 1: Hoover Dam

[Illustration 1] with link to larger version of photo.
(Bureau of Reclamation)

This image shows three views of the dam. The left side shows what a visitor looking upstream at the dam would actually see. The cut-away view on the right side shows features that would not be visible from the surface. Although not shown in the illustration, all of the features shown in the cut-away are duplicated on the other side of the dam. The cross section in the upper right hand corner is a side view.

Questions for Illustrations 1:

1. Look carefully at the cut-away view. Can you trace the course the water follows from the reservoir through the power plants and outlet works and then back into the river? How does that change if the level of the reservoir is getting too high?

2. How many of the features mentioned in Reading 2 can you find in this image? Is the image or the reading more useful in helping you understand Hoover Dam?

3. Reclamation engineers prepared hundreds of drawings for the construction company—all much more detailed than this simplified illustration. Why do you think the detailed drawings were necessary? How do you think the engineers decided where to locate the features shown here?

4. Look at the drawing in the upper right hand corner. Why do you think the dam had to be so thick at the bottom?

5. Find the penstocks that carry the water from the intake towers to the horseshoe-shaped powerhouse at the foot of the dam. One of the definitions of "penstock" is a pipe or conduit that carries water from a reservoir to electrical generating equipment. The Boulder Canyon Project Act said that the cost of building Hoover Dam had to be repaid by selling electricity and that contracts for all the electricity had to be signed before construction began. Why do you think that was required? When the contracts were signed, almost two thirds of the electricity went to Southern California. Why do you think that might have been the case?

Click here for a larger version of Illustration 1.



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