Finish the following sentences according to the text

1. In the design of almost every dam there must be.....

2...... permit to control the release of water.

3. Spillways must have the capacity to discharge major floods without...

4. Overflow spillways are widely used on....

5. A steep-sloped open channel is called a chute, or... and which is usually constructed of...

6. It may be constructed around.... when...

7.... is one in which the flow after passing over the crest is carried away in a channel running...

8. In a shaft spillway the water drops through...

9. Small shaft spillways may be constructed of...

10.... may be used if space is limited.

Answer the following questions.

1. Is spillway the dangerous valve for a dam?

2. What is an overflow spillway designed to?

3. What structure is relatively light and is well adapted to earth and rock-fill dams?

4. Why is the chute usually narrowed and then widened near the end?

5. What drains may be used?

6. Where is a side-channel spillway used?

7. Where can a shaft spillway be used?

8. What advantages have siphon spillways?

Copy out the table and complete it.