4. Decide whether the following statements are true or false according to the text.

1. The primary function of the intake structure is to permit discharge of water into the reservoir.

2. Intake towers are used where there is a small fluctuation of water level.

3. Intake towers may help flow regulation.

4. The lowest ports must be placed far enough above the bottom of the reservoir.

5. Gates are normally used on the outside shaft to regulate flow.

6. A wet intake tower has no water inside, while a dry one has some water inside.

7. A submerged intake may consist of an earth-filled crib.

8. Submerged intakes are widely used on huge projects.

9. Debris accumulated on the rack may be removed by hand.

1. Interior gate valves are often used to regulate flow for smaller heads.

2. Interior gate valves are used always in the fully open or fully closed position.

3. A butterfly valve is suited for moderate heads and high heads.

4. Slide gates are suitable for flow regulation under small heads.

5. Needle valves and tube ones placed at the upstream end of sluiceways are widely used on high-heads installation.

6. The upper conjugate depth and tailwater depth influence the measures necessary to control erosion and dissipate the energy of the spillway flow.

5. Complete the following sentences according to the text.

1. Intake structures are required at ..., depend on ... and vary from ... .

2. The primary function of the intake structure is to protect ... and to ... .

3. Ports may aid ... and permit ... .

4. Gates are normally provided on ... .

5. Each entry port is provided with ... .

6. Intake towers should be located so as ... .

7. Submerged intakes are widely used on small projects because ... .

8. Trash racks are made of ... .

9. A butterfly type of valve is best suited for ... .

10. ... are widely used for flow regulation, placed at the downstream end of the sluiceways and discharge directly into the atmosphere.

11. The problem facing the designer is to ... .

12. If the tailwater depth is greater than conjugate depth, ... .

13. If the tailwater depth is less than conjugate depth, ... .

6. Answer the following questions.

1) Where is an intake structure required at?

2) What does it depend on?

3) What are they provided with?

4) Where is it necessary to place the lowest ports? Why?

5) What does a wet intake tower consist of?

6) Why does a dry intake tower have no water inside?

7) What is an advantage of the dry towers?

8) How must intake towers be designed?

9) What does a submerged intake consist of?

10) What should the entrance to intakes and sluiceways be provided with?

11) How may the debris accumulated on the rack be removed?

12) What are most intakes and sluiceways provided with at their entrance?

13) What gates can be used to close the flow into large intake towers of the wet types?

14) Are interior gate valves often used to regulate flow for smaller heads?

15) In what position are interior gate valves used?

16) What is water flowing over a spillway or through a sluiceway capable of?

17) When does a hydraulic jump occur?

18) What do the location and character of the jump depend on?

19) Why will the depth of the flow gradually increase?