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

1) Three types of conduits are used to convey water.

2) The problems of canal location are different to highway location.

3) The soil in which the canal is constructed is often watertight.

4) Sometimes it may be economical to line a canal in order to reduce water seepage.

5) The distance from the intake to the canal should be wide to permit smooth flow.

6) An outlet is designed to dissipate excessive kinetic energy.

7) The entire structure in the chute is seldom concrete-lined.

8) The main purpose of the check is to lower the upstream water level to permit water diversion.

9) Settling basins are sometimes constructed just above to the point of water diversion.

10) A flume is supported aboveground.

11) The most permanent type of flume is a concrete flume.

12) It is cheaper to convey water by flume or canal than by tunnel.

Match according to the text.

1) Canal intakes   2) Chutes or drops   3) Outlet   4) Culverts or tunnels   5) Checks   6) Turnouts   7) Wasteways   8) Drainage culverts   9) Settling basins   10) Sand traps

are used

a) to divert flow from the main canals to smaller distribution ones. b) to regulate the flow in the canal. c) to accumulate sediment and to sluice it from a canal. d) to avoid excessive slope in the canal. e) to carry water through the obstructions. f) to convey water through a highway cut. g) to prevent entering excess storm water to a canal. h) to dissipate excessive kinetic energy. i) to raise the upstream water level to permit water diversion. j) to collect and to return back sediment to a river. k) to return excess water to the stream and to sluice sediment from a canal.

Answer the following questions.

1) What types of conduits are used to convey water?

2) What forms may the open channel take?

3) Open channels are characterized by a free water surface, aren’t they?

4) Why is the problem of canal location more difficult then the problem of highway location?

5) Why are canals lined?

6) What types of lining are used to reduce seepage losses from canals?

7) What appurtenances are necessary for the proper operation of canals?

8) What helps to regulate flow in the canal and to distribute water?

9) Where are flumes used to convey water?

10) Can wooden flumes be of rectangular, triangular and semicircular cross sections?

11) What types of wood is used in timber flumes?

12) Semicircular steel flumes are widely used, aren’t they?

13) Will the useful life of a well-maintained steel flume range from 15 to 50 years?

14) What is the disadvantage of concrete flumes?

15) Why are flumes and canals sometimes covered?

16) Is it always cheaper to convey water by tunnel than by flume or canal?

17) Are tunnels made use of horseshoe or circular section?

18) What may be used to prevent collapse of a tunnel if the tunnel material is unstable?

19) What tunnels need not be lined?

20) Do tunnels act as open channel when they are full of water?

Make a plan of the text and write a summary of the text.

 

Language Focus

 

Odd one out.

a) a channel, a canal, a flume, a check, a tunnel, a filled pipe

b) clay, asphalt, cement mortar, concrete, steel, gunite

c) pine, fir, redwood, cypress, paint

d) rectangular, circular, liner, triangular, semicircular, horseshoe

e) turnouts, wasteways, overchute, settling basins, depressions

f) a chute, an intake structure, a long section, an outlet

 

Make sure you know the verbs formed from the following nouns.

characteristic → …	location → …	reduction → …
lining → …	elevation → …	dissipation → …
change → …	facility → …	excess → …
collection → …	collapse → …	accumulation → …
galvanization → …	evaporation→ …	pollution → …
diversion → …	regulate → …	avoidance → …

Match the words with their synonyms.