A Subdivisional Officer generally receiv_Irrigation works

applications from members of the irrigating community regarding--among

other matters--outlets or watercourses. Generally these applications are

made over to the zilladar to be reported on. In a large number of cases

the applicant states that the irrigation of his land or “holding” is not

satisfactory, or has fallen off, and sometimes he asks that it may be

transferred, wholly or in part, to another watercourse which he thinks

will give a better supply. In all such cases, and in some others, the

first requirement is a statement of the irrigation figures. The

irrigation register gives only the total for the watercourse. A printed

form should be prepared with spaces for showing the name of the

distributary, villages, watercourses, holdings and applicants concerned,

and the nature of the application. Below this is a form, prepared

somewhat as shown below. When this form is filled in, the state of

affairs can at once be seen and much trouble is saved. The zilladar

obtains the figures from the old field registers. The amount of detail

required as to the applicant’s lands depends on the nature of his

application. If it deals with only part of his land the other parts

should also be shown. He may for instance be giving a disproportionate

share of water to one part. If a transfer to another watercourse is

asked for, the figures for that watercourse are also required.

-----------------+----------------------------------+--------+--------

Areas in Acres. | Applicant’s Holding. |Total of|Total of

|-------+---------+---------+------| Water- |Distrib-

-----------------+-------+---------+---------+------+--------+--------

| | | | | |

Net {19...-19...| | | | | |

irri-{19...-19...| | | | | |

gated{19...-19...| | | | | |

| | | | | |

-----------------+-------+---------+---------+------+--------+--------

| | | | | |

| | | | | |

-----------------+-------+---------+---------+------+--------+--------

| | | | | |

| | | | | |

-----------------+-------+---------+---------+------+--------+--------

| | | | | |

| | | | | |

-----------------+-------+---------+---------+------+--------+--------

If an application refers to a whole watercourse, the Subdivisional

Officer can frequently, with the aid of an irrigation register and a set

of chak maps, both kept up to date, dispose personally of the case. A

good plan is to settle cases when on tour near the place concerned, the

applicant and the zilladar being present as well as any other persons

concerned. A certain number of cases have to come up again on the

following tour, but all are settled in less time than is occupied if the

papers go up and down between the Subdivisional Officer and the

zilladar, the “file” of papers in any particular case being constantly

swollen by reminders from the applicant.[39] Moreover, the applicants

know that their views are known to the Subdivisional Officer. If the

outlets on a channel need a general remodelling, such applications as

those under consideration receive attention in connection with the

scheme. Otherwise all the applications concerning one distributary can

be considered together. If, however, a case is pressing, or the steps to

be taken obvious, it can be settled without reference to any other case.

[39] The plan of personal settlement is distasteful not only to the

subordinates, but to the _munshi_ who has charge of the “vernacular

files.” Ordinarily he can delay a case, or manipulate it to some

extent.

The general arrangements for the “revenue” work or assessment of water

rates have been stated in Art. 1. In the Punjab the remissions for

failed crops are a source of trouble. In some districts the failed areas

are small, and no particular trouble arises, but in other districts such

areas are often very large. On perennial canals the crop inspection is

done by the zilladars, on most of the inundation canals by the

subordinates of the District Magistrate.[40] In both cases the amount of

labour involved is enormous, and the corruption to which the system

gives rise is also enormous. In the case of the inundation canals the

superior staff of the District Magistrate nominally make checks, but the

time at their disposal is wholly inadequate. In the case of the

perennial canals the Canal Engineers are able to exercise considerable

checks, but nothing like enough. In fact the state of a crop and the

proportion of the charge on it which should be remitted is a difficult

thing to judge, even if the subordinates were without guile. It is

understood that a new and statesmanlike system is now to be introduced,

the District Magistrate deciding, in consultation with the Executive

Engineer, whether the season is such as to call for any general

remission for each kind of crop, and, if so, to what extent. The

proportion to be remitted in that crop is then to be fixed, and it is to

be the same for every one.

[40] Officially called the “Collector” in some provinces, and “Deputy

Commissioner” in others.

It has been mentioned that some irrigation is effected by lift. The

simplest form of lift is a horizontal pole which rests, not far from its

thick end, on a support. From its thick end is suspended a bucket, and

from its thin end a weight. A man lifts the thin end so that the bucket

then dips into the water and is filled. Pulling down the thin end he

raises the bucket and empties it. A greatly improved lifting apparatus

is the Persian wheel which is vertical and has slung from it, like the

buckets of a dredger but moving vertically, a number of earthen jars,

which scoop up the water. As each jar passes over the top of the wheel

it assumes a horizontal position, discharges its water into a shoot, and

descends in an inverted position. The wheel is moved by a simple

cog-wheel arrangement actuated by a bullock which is driven round and

round in a circular track. The Persian wheel is used for lifts of any

height. The lift from a canal watercourse is a few feet, that from a

well may be 50 feet or more.

Most persons consider that a system of charging for water by volume

would be a very great advance on present methods. It has been said that

if the water were wasted it would be difficult for the cultivators to

bring home the responsibility to any individual. This objection does not

seem to have great force. Every individual would have a direct interest

in economising the water, and any cultivator who was habitually careless

would soon be detected by the others. In all probability the result

would be a great improvement in the duty of the water. But the justice

of any very rigid system of charging by volume is somewhat doubtful. The

great difference in the duty of water on different watercourses has been

mentioned more than once. Many of the causes of this are beyond the

control of the farmers, and it would probably be necessary to charge

reduced rates to some of them.

CHAPTER IV.

THE PUNJAB TRIPLE CANAL PROJECT.[41]

[41] See Report on the Project Estimates of the Upper Jhelum, Upper

Chenab, and Lower Bari Doab Canals.

[Illustration: FIG. 26.]

1. =General Description.= Fig. 26 shows part of the Punjab. The areas

marked L.J., L.C., U.B.D., and S.C. are already irrigated by the Lower

Jhelum, Lower Chenab, Upper Bari Doab[42] and Sirhind Canals. The areas

which it is considered very desirable to irrigate, and which are

provided for in the Triple Canal Project, are marked U.J., U.C., and

L.B.D., and the new canals are shown by dotted lines. Other areas

needing irrigation lie on the left bank of the lower part of the Sutlej,

partly in British territory and partly in Bahawalpur State, and one

area,[43] of scant rainfall and subject to occasional famine, lies

immediately South of the Sirhind Canal tract. There is also a very large

area between the Indus and the Jhelum, and it has been proposed to

irrigate it from the Indus, but on account of the presence of sand-hills

the project is not likely to be so useful as others, and it is held in

abeyance. Perhaps a small canal may be constructed, as a tentative

measure, to irrigate part of the tract.

[42] Doab means “two waters,” or the tract between two rivers. The

names of the three Doabs under consideration are formed from those of

the rivers. They are called the Jech (Jhelum-Chenab), Rechna

(Ravi-Chenab), and Bari (Beas-Ravi) Doabs.

[43] It would be very expensive to bring water for this tract from the

Beas and across the Sutlej.

The winter discharges of the rivers (available for the rabi crop) after

the existing irrigation has been supplied, are as follows:

Indus, 9,434 c. feet per second (minimum)

Jhelum, 6,800 „ „ (average)

Chenab, Nil

Ravi, Nil

Beas, 4,000 „ „ (minimum)

Sutlej, Nil

In summer all the rivers have discharges (available for the kharif crop)

far exceeding any requirements. It was at one time proposed to supply

the Lower Bari Doab Canal from near the junction of the Beas and Sutlej,

and a project for this was prepared, but before it was sanctioned a

proposal was put forward to convey the surplus water of the Jhelum

eastward across the Chenab and Ravi. This valuable suggestion was made

by Sir James Wilson, who was then Settlement Commissioner of the Punjab,

and, independently, by the late Colonel S. L. Jacob, R.E., who had been

a Chief Engineer in the Punjab. The proposals were, however, to take off

the supply from the Jhelum lower down than as now arranged in the Triple

Project. This would have resulted in only a partial utilisation of the

Jhelum water, in mutilation or heavy alterations to the existing Lower

Jhelum and Lower Chenab Canals, in for ever debarring the Upper Jhelum

and Upper Chenab tracts from irrigation, and in a very costly scheme for

the Lower Bari Doab Canal.[44]

[44] Colonel Jacob made his suggestion when in England after retiring

from India, and when he had no levels to guide him.

The Triple Project as prepared by Sir John Benton, K.C.I.E., recently

Inspector General of Irrigation in India, gets over all the above

objections. The Upper Jhelum Canal is to irrigate the country which it

traverses, and in the winter, when the supply in the rivers is

restricted, it is to deliver into the river Chenab, above the weir at

the head of the Lower Chenab Canal, a discharge equal to that drawn out

higher up by the Upper Chenab Canal.[45] Thus the Lower Chenab Canal,

which at present draws off the whole of the water of the Chenab in

winter, will not be injuriously affected in any way. The Upper Chenab

Canal after irrigating its own tract is to deliver a large volume of

water into the Ravi. The water will be taken across that river by a

level crossing, and supply the Lower Bari Doab Canal. The water brought

into the Sutlej from the Beas will remain available for irrigation on

the left bank of the Sutlej, or possibly for the dry tract South of the

Sirhind Canal area. This fine scheme presented many difficulties and is

necessarily costly. The water has to be conveyed a great distance, and

there will be much loss by absorption. The Ravi crossing will be a very

heavy work. The Upper Jhelum Canal has to be taken by a circuitous

course round a range of hills, and to cross numerous heavy torrents. The

scheme will, however, prove remunerative in spite of immense

difficulties as to labour, caused by the outbreak of plague in the

Punjab a few years ago.

[45] The Indus is at a higher level than the Jhelum. The latter river

runs in a comparatively deep valley, and it is unfortunately

impossible to convey the water of the Indus across this valley.

2. =Areas and Discharges.= The figures on which the discharges in the

Triple Project are based form a useful and interesting object lesson. In

order to obtain sufficient water in the winter, it is necessary to

reduce the rabi supply to the existing Lower Jhelum Canal. The figure

above given for the Jhelum indicates the supply available after the

reduction. More water will be supplied to the Lower Jhelum Canal for the

kharif, the canal being enlarged for this purpose, and its total

irrigation will be unaffected. The proportion of the culturable

commanded area to be irrigated in the new tracts is 75 per cent., but

from this the area irrigated by wells in the Upper Jhelum and Upper

Chenab tracts is deducted. On the Lower Bari Doab Canal there is little

well Irrigation, but there are some low-lying tracts near the rivers,

and of these only 50 per cent. will be irrigated. The kharif and rabi

areas are in all cases to be equal.

The areas to be irrigated in each crop are as below--

Lower Jhelum Canal 383,091 acres

Upper Jhelum Canal 172,480 „

Upper Chenab Canal 324,184 „

Lower Bari Doab Canal 441,264 „

---------

Total 1,321,019 „

The total, excluding the existing Lower Jhelum Canal, is 937,928 acres.

With an equal area in the other crop, the new annual irrigation amounts

to 1,875,856 acres.

The kharif duty is taken as 100 acres at the distributary heads, this

being about the figure actually obtained on the Lower Chenab and Upper

Bari Doab Canals, and the required kharif discharges at the distributary

heads are:

Lower Jhelum 3,821 c. feet per second

Upper „ 1,725 „ „

„ Chenab 3,242 „ „

Lower Bari Doab 4,413 „ „

-----

Total, excluding Lower Jhelum 9,380 „ „

The losses of water in canal and branches have been found to be, on the

Upper Bari Doab Canal 10 c. feet per second, and on the Lower Chenab

Canal 8 c. feet per second, per million square feet of wetted area

respectively. The conditions of the latter canal most resemble those on

the new canals under consideration. The losses calculated on the wetted

areas of the channels, as designed, at 8 c. feet per second per million

square feet, are as follows, in c. feet per second:

Lower Jhelum Canal 624} 1,288

Upper Jhelum Canal 664}

Upper Chenab Canal 1,161} 2,126

Lower Bari Doab Canal 965}

-----

Total 3,414

But in dry years the canals will be worked in rotation during the rabi,

the Upper Chenab and Lower Bari Doab Canals being worked together, and

the Upper Jhelum and Lower Jhelum together.

When the Lower Jhelum Canal is closed, in course of rotation, the Upper

Jhelum Canal will still be flowing, and the loss in it, 664 c. feet per

second, has to be added to the figure (2,126) given above, thus bringing

up the loss to 2,790 c. feet per second.

In order to ascertain what the state of affairs will be in the rabi, the

statistics obtained on the Lower Chenab Canal were examined. These show

that the rabi duty at the distributary heads on that canal is 206 acres.

On the Upper Bari Doab Canal the duty at the distributary heads is 263

acres, but 11 per cent. of the area receives only “first waterings.” The

duty based on the remaining area is 234 acres. But the above duties are

only attained by running higher supplies in October and March than

during the intervening four months of the crop. The following remarks

and figures are taken from the Report on the Project Estimates:--

“The statistics of working of distributaries of the Chenab and Bari Doab

Canals give the average discharges shown in the following table for the

three years ending with 1903-04. The losses by absorption are calculated

on the wetted areas for the different rotational periods. The average

discharge less absorption is the supply which reached the heads of the

distributaries.

CHENAB CANAL.

------------------+--------------------------------------------+------

| PERIOD. | AVER-

+------+------+-----+-----+-----+-----+------+ AGE.

| ber | ber | vem-| cem-|ary. | ru- | |

| 1st- | 16th-| ber | ber| | ary | |

| 15th | 31st| | | | | |

------------------+------+------+-----+-----+-----+-----+------+------

| Cu- | Cu- | Cu- | Cu- | Cu- | Cu- | Cu- | Cu-

canal |10,196|10,285|7,788|5,593|5,127|5,500| 6,603| 6,809

| | | | | | | |

Deduct absorption | 1,633| 1,633|1,250|1,053|1,032|1,171| 1,433| 1,262

+------+------+-----+-----+-----+-----+------+------

area | 8,563| 8,652|6,538|4,510|4,095|4,329| 5,170| 5,546

+------+------+-----+-----+-----+-----+------+------

1,164,595 acres | 8,631| 8,721|6,590|4,576|4,128|4,364| 5,211| 5,591

| | | | | | | |

new projects | 3,414| 3,414|2,139|2,139|2,139|2,139| 3,414| 2,564

+------+------+-----+-----+-----+-----+------+------

at heads of canals|12,045|12,035|8,729|6,715|6,267|6,503| 8,625| 8,155

------------------+------+------+-----+-----+-----+-----+------+------

“The average discharge given by the third line is 5,546, and the average

area being 1,155,685 acres, the duty at the heads of distributaries was

208.

“The area 1,164,595 is the perennial rabi irrigation of the new

projects, the area 156,424 acres, receiving only first waterings, being

omitted to admit of a fair comparison, and is only 1 per cent. under the

average attained on the Chenab Canal in the three years for which the

table is prepared.

“The absorption added for the two first periods is on the supposition

that all the canals are open throughout October and March, tatilling[46]

with an average absorption loss of 2,139 cusecs[47] being in force

during the other four months. The last line of the table shows the

average Rabi discharge required by the new projects at the heads of

canals, inclusive of all losses calculated on the Chenab Canal basis of

a duty of 208 acres per cusec obtained at the heads of distributaries.

[46] “Tátíl” is the Indian word for rotational closure.

[47] “Cusec” is used in India for c. ft. per second.

“The Bari Doab Canal statistics furnish the means of the adequacy of

available supply being gauged. The following table furnishes particulars

for the average supply of water entering the head of the canal for the

five years 1898-99, 1899-1900, 1901-02, 1902-03, 1903-04. The figures

for the year 1900-01 are omitted, as it was a very abnormal one of very

plenteous supply and heavy rainfall:--

“The average irrigation for the five years in question was 442,302

inclusive of 11 per cent. which only receives first waterings. This

divided by the average supply, 1,685, entering the head of a canal gives

a duty of 263 acres per cusec at the heads of distributaries.

BARI DOAB CANAL.

------------------+--------------------------------------------+------

| PERIOD. | AVER-

+------+------+-----+-----+-----+-----+------+ AGE.

| ber | ber | vem-| cem-|ary. | ru- | |

| 1st- | 16th-| ber | ber| | ary | |

| 15th | 31st| | | | | |

------------------+------+------+-----+-----+-----+-----+------+------

| Cu- | Cu- | Cu- | Cu- | Cu- | Cu- | Cu- | Cu-

canal | 3,769| 2,896|2,170|1,755|1,622|1,916| 2,909| 2,284

| | | | | | | |

Deduct absorption | 599| 599| 599| 599| 599| 599| 599| 599

------------------+------+------+-----+-----+-----+-----+------+------

(_a_) | 3,170| 2,297|1,571|1,156|1,023|1,317| 2,310| 1,685

------------------+------+------+-----+-----+-----+-----+------+------

figures line (_a_)| 9,510| 6,891|4,713|3,468|3,069|3,951| 6,930| 5,055

| | | | | | | |

new projects | 3,414| 3,414|2,139|2,139|2,139|2,139| 3,414| 2,564

------------------+------+------+-----+-----+-----+-----+------+------

at heads of canals|12,924|10,305|6,852|5,607|5,208|6,090|10,344| 7,619

------------------+------+------+-----+-----+-----+-----+------+------

“The rabi irrigation of the new projects is 1,321,019 acres,[48] and

this divided by 442,302 gives approximately the multiplier 3 referred to

at (_a_) in the above table.

[48] Including the Lower Jhelum.

“The figures given in the above table and in the foregoing remarks

relate to the aggregate of the areas in the rabi which receives a

perennial supply and which only receives first and last waterings. On

the Upper Bari Doab Canal the rabi which receives perennial irrigation

is averagely 393,649 acres; the average supply of 1,685 cusecs gives on

this area a duty of 234 acres per cusec at the heads of the

distributaries.

“In the case of the three projects the aggregate _rabi_ area receiving

perennial irrigation as shown by the table, paragraph 21[49] _supra_, is

1,164,595 acres: this is 2·96 times 393,649; so that the proportional

supply required on this basis would be slightly less than that given by

the multiplier 3 in the above table.

[49] Not printed. The area is the total rabi area less the area which

is to receive only first waterings.

In explanation of the difference of the duties:--

Lower Chenab Canal 208 acres per cusec,

Upper Bari Doab Canal 234 ditto,

it may be stated that the Lower Chenab Canal is a comparatively new

work, and that the duty has been steadily rising and, with the perfect

watercourse system, may be relied on to reach the Upper Bari Doab Canal

234 acres per cusec in the course of time for water arriving at the

heads of distributaries.

* * * * *

“27. =Summary of conclusions as to sufficiency of supply.=--The

following table shows all the foregoing results in a form readily

admitting of comparison:--

----------+----------------------------------------------------------+

PARTIC- | PERIOD. |

ULARS. +---------+--------+-------+-----+------+---------+--------+

| 15th | 31st | ber. | cem-| ary.| ary. | |

| | | | | | | |

----------+---------+--------+-------+-----+------+---------+--------+

| | | | | | | |

vourable |{ 21,400 | 15,150 |}11,850|8,626|11,200|{ 13,100 | 21,250 |

years 1 |{(13.063)|(13,063)|} | | |{(13,063)|(13,063)|

in 4 | | | | | | | |

| | | | | | | |

Ordinary |{ 13,900}| 11,850 | 10,000|7,400| 7,600| 9,100 |{16,500 |

years 2 |{ 13,063}| | | | | |{13,063 |

in 4 | | | | | | | |

| | | | | | | |

Dry years | 10,150 | 9,100 | 7,275 |5,950| 5,610| 6,100 | 11,345 |

1 in 4 | | | | | | | |

| | | | | | | |

Minimum of| 9,710 | 8,003 | 6,624 |5,810| 5,563| 5,163 | 9,791 |

+---------+--------+-------+-----+------+---------+--------+

Lower | 12,045 | 12,135 | 8,729 |6,715| 6,267| 6,503 | 8,625 |

| | | | | | | |

Upper Bari| 12,924 | 10,305 | 6,852 |5,607| 5,208| 6,090 | 10,344 |

for 5 | | | | | | | |

----------+---------+--------+-------+-----+------+---------+--------+

----------+-------+-------+---------+-----------+-----------

ULARS. +supply |loss by|heads of | lated on | lated on

| in |absorp-|distribu-|1,321,019 |1,164,595

----------+-------+-------+---------+-----------+-----------

| | | | |

| | | | |

vourable |}11,811| 3,414 | 8,397 | 158 | 139

years 1 |} | | | |

in 4 | | | | |

| | | | |

Ordinary |} 9,946| 2,989 | 6,957 | 189 | 167

years 2 |} | | | |

in 4 | | | | |

| | | | |

Dry years | 7,651| 2,564 | 5,087 | 259 | 229

1 in 4 | | | | |

| | | | |

Minimum of| 6,968| 2,458 | 4,510 | 293 | 258

+-------+-------+---------+-----------+-----------

Lower | 8,155| 2,564 | 5,591 | 236 | 208

| | | | |

Upper Bari| 7,619| 2,564 | 5,055 | 261 | 230

for 5 | | | | |

----------+-------+-------+---------+-----------+-----------

“The 13,063 shown in brackets represents the parts of the available

supply which the canals can carry, the capacity being as follows:--

Cusecs.

Lower Jhelum Canal 4,563

Upper Jhelum Canal 8,500

------

Total 13,063

------

“The average supplies and duty figures are based on the 13,063 cusec

maximum capacity and not on the larger available supplies written above

these figures where they occur.

“The above table goes to show the following:

(_i_) In order to utilize the large supplies available in the Jhelum

River in October and March every year and in some or all of the

intervening months in other years, it is advisable to give the Upper

Jhelum Canal the large capacity of 8,500 cusecs proposed.

(_ii_) In favourable and ordinary years, that is, in 3 out of 4, the

available supply will be ample, as shown by the low duties of 189 and

167 compared with those obtaining on the Lower Chenab and Upper Bari

Doab Canals.

(_iii_) In dry years, that is, 1 in 4, it will be necessary to attain

a duty almost exactly the same as that now obtaining on the Upper Bari

Doab Canal.

(_iv_) That an exceptionally dry year might occur once in 14 years,

when the supply would be 10 per cent. short of that required by the

average Upper Bari Doab Canal standard of requirements: such

exceptional cases should be met by remissions, which will be far

preferable to wasting the good supplies of 13 years out of 14.

(_v_) That the occasional occurrence of dry years makes it inadvisable

to attempt a greater proportion of rabi than half of the annual

irrigation.”

3. =Remarks.= The Report on the Project estimates gives, for each tract,

remarks on its soil, rainfall, height of subsoil water, circumstances as

to existing irrigation from wells or small canals and liability to

floods. On a consideration of these matters the decision as to the

particular parts of the tracts which are to be irrigated and the areas

which are, in the rabi, to receive only restricted irrigation,

depends.[50]

[50] It is not unusual, in tracts where the level of the subsoil water

is high, say within 15 feet of the surface, to have some “kharif

distributaries.” These are closed in the rabi. This tends to prevent

water-logging of the soil. In the rabi the people lift water from

wells. There may also be kharif distributaries in dry tracts if there

is no water to spare in the rabi.

In calculating the sizes of the canals, N in Kutter’s co-efficient was

taken at ·020. In sharp curves the bed is paved on the side next the

concave bank. In high embankments where the soil is sandy the best

material is used as a core wall. The torrent works on the Upper Jhelum

Canal have been mentioned in _River and Canal Engineering_, Chapter XII.

Regarding the effect of the new canals on the inundation canals which

take off, lower down, from the Chenab below its confluence with the

Jhelum, it has for long been the policy to gradually shift the heads of

these canals upstream in order to obtain better supplies, or rather to

counteract the effect of the abstraction of water for the recently

constructed Lower Chenab and Lower Jhelum Canals. Any such abstraction

of water has not much effect on the floods, but it has much effect in

April and May, when the rivers have not fully risen, and in September,

when they are falling.

In order to estimate the effect on the water level of the Chenab--below

its junction with the Jhelum--it was necessary to observe discharges of

the river, not only in the winter when it is low, but in the summer when

it is high. The depth of the water was in some places 40 feet, and the

stream 2,000 feet wide. Fortunately the Subdivisional Officer was a

native of India and did not much mind the sun. A discharge curve (_River

and Canal Engineering_, Chapter III. Art. 5,) having been prepared, it

was possible to construct a diagram with periods of time as the

abscissas, the ordinates representing the average known gauge readings

on the different dates and another set of ordinates representing the

probable discharges. By deducting the discharges which it was intended

that the new perennial canals should draw off, it was possible to draw

fresh ordinates representing the diminished river discharges and the

reduced river gauge readings corresponding to them. It was found that

the water level would be lowered by about 1·3 feet in April and May, and

by about 1·5 feet in September. It was, however, shown that by shifting

the heads of the inundation canals upstream--the gradients of the canals

being flatter than that of the river--the effect of the lowering of the

water level could, as heretofore, be nullified.

CHAPTER V.

PROPOSED IMPROVEMENTS IN IRRIGATION CANALS.

1. =Preliminary Remarks.=--The chief improvements which have been under

consideration during recent years are three in number. The first is

increased economy of water in its actual use in the fields; the second

is reduction of the losses by absorption in the channels; and the third

is distribution by means of modules.

Regarding the first, it has long been known that the ordinary methods of

laying on the water are more or less wasteful. In California, when the

water instead of being applied to the surface of the ground, is brought

in a pipe and delivered below the ground level, the duty is increased

from 250 to 500 acres. In India a field is divided, by means of small

ridges of earth, into large compartments. The water is let into a

compartment and gradually covers it. By the time the further side is

soaked the nearer side has received far too much water. Frequently the

water for a compartment, instead of being carried up to it by a small

watercourse, is passed through another compartment and this adds to the

waste. Also the number of waterings given to a crop is often 5 or 6,

when 4 would suffice. Experiments made on the Upper Bari Doab Canal, by

Kennedy, showed that the water used in the fields was nearly double what

it might have been. The 53 c. ft. shown in Chapter 1, Art. 4, as

reaching the fields, were used up when 28 c. ft. would have sufficed. It

is not certain that the waste is generally quite as much as the above.

It is possible that the restricted supplies might have given smaller

yields of crops. More recent experiments made by Kanthack on the same

canal give the needless waste as about 25 per cent. The field

compartments ought, according to Kennedy, to be 70ft. square, the small

branch watercourses being 140ft. apart. It would be better to have still

smaller compartments, but this would be rather hard on the people.

At one time Government issued orders, in Northern India, that

compartments of 1296 square feet were to be used, and that, otherwise,

increased water rates would be charged, but the orders were never

enforced. They were thought to press too hardly on the people. Extreme

measures for enforcing economy in the use of water in any country are

likely to be introduced only when they become absolutely necessary owing

to the supplies of water being otherwise insufficient.

2. =Reduction of Losses in the Channels.=--For several years experiments

have been going on in the Punjab as to the effect of lining watercourses

with various materials. The following conclusions have been arrived

at[51]:--

[51] _Punjab Irrigation Paper_ No. 11 C. “Lining of Watercourses to

reduce absorption losses. Experiments of 1908-1911.”

I. ORDINARY UNLINED TRENCHES.

(_a_) The rate of absorption varies greatly, and this is due probably

to unequal fissuring of the upper layers of the soil.

(_b_) The rate of absorption in the three hottest months averaged

·0571 feet per hour, or more than double the rate (·026) in the three

coldest months. The difference is ascribed to the greater viscosity

of the water when cold.

(_c_) The average losses with canal water were ·0315 feet per hour, or

8·75 c. feet per second per million sq. feet.[52] With well water the

figures were ·1096 and 30·5. The conclusion is that the silt in canal

water reduces the losses by more than two-thirds.

[52] This loss of 8·75 c. ft. per second was in water only about a

foot deep. This confirms the conclusion arrived at in Chapter I, Art.

4, that the depth of water is not a factor of much importance.

(_d_) With canal water the average loss decreased by 40 per cent.

(from ·0491 to ·0293) in about four years. This was no doubt due to

the effect of the silt. With well water the loss at the end of four

years (·2293) was nearly four times as great as at first (·0591). This

may have been due to removal of the finer particles of soil by the

water, but the experiments were made at only one place, and were not

conclusive.

II. LINED TRENCHES.

(_e_) With trenches lined with crude oil ¹⁄₁₆ inch thick, or with

Portland cement ¹⁄₁₆ inch thick, or with clay puddle 6 inches thick,

the “efficiency ratios,” as compared with unlined trenches, are

respectively about 4·0, 5·7 and 5·7, the age of the lining being four

years. The efficiency ratio is the inverse of the loss. Thus with an

efficiency ratio of 3 the loss in the lined trench is 33 per cent. of

that in the unlined trench.

(_f_) The efficiency ratio in the case of oil may diminish at the rate

of 10 per cent. per annum, but in the case of cement and clay puddle

it tends to increase rather than to decrease.

Assuming that the efficiency ratios are only 3·0, 4·5 and 4·5, and that

the loss in an unlined channel is 8 c. feet per second per million sq.

feet, the saving in water by using channels lined with oil, cement and

puddle respectively would be 5·33, 6·25 and 6·25 c. feet per second. The

average duty of the water at the canal head is about 242 acres, and the

average revenue per acre is Rs 3·93. The revenue from 1 c. ft. of water

at the canal head is thus Rs 950. Only about half the water reaches the

fields (Chapter I., Art. 4), and the revenue from 1 c. ft. of water

which reaches the fields is about Rs 1900. The mean of the above two

sums is Rs 1425. If 6 c. ft. of water per second could be saved the

revenue would be increased by Rs 8,550 per annum.

The cost of lining a million square feet of channel with oil, cement and

puddle is estimated at Rs 30,000, Rs 27,500 and Rs 35,000 respectively.

Allowance has to be made for the fact that watercourses flow

intermittently, and that a lined channel gives no saving when it is not

in flow, also that extensions of canals might have to be undertaken in

order to utilise the water saved. After making these allowances it is

estimated, in the paper above quoted, that the saving effected by lining

a million square feet with oil, cement or puddle represents the interest

on a capital sum of Rs 69,300, Rs 81,250 and Rs 81,250 respectively, or

2 or 3 times the sums sunk in constructing the linings.

Hitherto the experiments have been carried out on a moderate scale, but

extensive operations are now being undertaken on the Lower Chenab

Canal, and possibly on others.

In cases where it is not desired to incur much expenditure, it may be a

good plan to construct watercourses to a cross section somewhat larger

than that ultimately desired. The silt deposited on the bed and sides

forms, in most cases, a more impervious lining than the original soil.

The same plan can be adopted in the tail portion of a distributary. In a

larger channel there would be less certainty that any deposit would take

place unless short lengths, at frequent intervals, were excavated to the

true or ultimate section, so as to form weirs and spurs; and even these

might not stand.

In Italy, in cases where the water naturally contains lime in

suspension, the beds of canals have become gradually watertight by the

deposit of lime in the channel.[53] In some cases lime has been

artificially added. It appears that a considerable period of time is

necessary for the process.

[53] Min. Proc. Inst. C. E. Vol. CXVI.

3. =Modules.=--A module is an appliance which automatically gives a

constant discharge through an aperture, however the water level on

either the upstream or downstream side of the aperture may fluctuate. In

an old and simple form of module there is a horizontal orifice in which

works loosely a tapering rod attached to a float. The water passes

through the annular space surrounding the rod. If the water level rises,

the rise of the float brings a thicker part of the rod to the orifice

and reduces the annular space. In another kind of module the water is

discharged through a syphon. If the water level alters, the syphon moves

in such a way that the head, or difference between the levels of its

two ends, remains the same. The great objections to modules are that

they are liable to get out of order or to be tampered with. A module

recently invented and patented by Gibb[54] has no movable parts, and is

not liable to these objections.

[54] For description see Appendix H.

A few years ago the question of the desirability of using modules for

the outlets of distributaries in India was raised. The opinions of a

large number of the senior canal engineers were called for and

considered, and since then the subject has been thoroughly discussed.

There are certain inherent difficulties in the way of moduling the

outlets of a distributary. Owing, for instance, to rain further up the

canal, or to the closure of a distributary owing to a breach in it, the

canal supply may increase, and it may be necessary to let more water

into the distributary under consideration. Under the present system any

excesses of water are automatically taken by the outlets. If all outlets

were rigidly moduled they would discharge no more than before the excess

supply came in, and the excess supply would all go to the tail of the

distributary, and, most likely, breach the banks. To get over this

difficulty, the module has to be so arranged that when the water level

in the distributary rises to a certain “maximum limit” the module ceases

to act as such, and the discharge drawn off from the distributary

increases as the water level rises. Again, the discharge of the

distributary may at times be considerably less than its full supply. In

order that, in such a case, the outlets towards the tail of the

distributary may not be wholly deprived of water, it has to be arranged

so that when the water level in the distributary falls below a certain

“minimum limit” the modules cease to act as such, and draw off supplies

which are less the lower the water level. Such supplies are not in

proportion to the full supplies of the outlets. It will, however, be

shown presently that low supplies need seldom be run. When a

distributary, say the upper reach, contains silt, the water level

corresponding to a given discharge is higher than before, and care has

to be taken that the maximum limit is high enough. At the same time the

minimum limit must be so low that it will not be passed when the silt

scours out. The difference between the maximum and minimum limits is

called the “range” of the module.

In Gibb’s module the above conditions can be complied with. The module

is placed outside the bank of the distributary. The water is drawn off

from the distributary by a pipe, whose lower edge is at the bed level of

the distributary, and delivered from the module into the watercourse

through a rectangular aperture at a higher level than that of the pipe.

It is possible that, owing to the high level of the aperture, some

rolling silt which would otherwise have passed out of the distributary

may remain in it. The height of the aperture also prevents the

watercourse from drawing off any water at all when the water level of

the distributary falls below a certain level, but this objection is not

important. An escape weir or notch is provided so that when the water

level in the distributary rises to the maximum limit some water

overflows into the watercourse. On the whole it appears that all

difficulties can be got over, though a good deal of care and precision

is necessary in fixing the exact height of the maximum and minimum

limits.

The difficulties under consideration will all be reduced if some of the

outlets on a distributary are left unmoduled, and this is desirable on

other grounds. When the supply is normal, _i.e._ between the maximum and

minimum limits, and all modules are working, the supply entering the

distributary must be regulated with great precision. The outlets draw

off a certain supply. If less than this enters the distributary the tail

outlets must go short. If more enters there will be a surplus at the

tail, though it can probably be disposed of, because the tail water will

rise above the maximum limit. For short periods, say an hour or two, no

trouble arises because the distributary acts as a reservoir, the water

level rising to take in any excess supply, and falling to allow for a

deficiency. At the tail the rise and fall may be hardly perceptible. But

if the supply were deficient for a whole night the tail outlets would

certainly go short. This could theoretically be remedied to some extent

by letting in an excess supply for a short time and causing the water

level at the tail to rise above the maximum limit, but in practice no

such system of compensation could be worked. The very fact of the tail

outlets having gone short for a night would not be known. The proper

method of preventing any such troubles as those under consideration is

to leave some of the outlets on the distributary un-moduled.

It has been more than once mentioned that there are periods when a

distributary is run, not full, but about three-fourths full. If that

were done in the case of a distributary whose outlets were mostly

moduled, the water level would probably be below the minimum limit, and

the modules would not be acting as such. The outlets would not, under

these circumstances, obtain their proper proportionate supplies. This

difficulty can, no doubt, be got over by running the distributary full

for short periods at a time instead of three-fourths full for longer

periods. The people, when once they understood the case, could arrange

to use the water in greater volume for two days instead of in smaller

volume for three. If this arrangement comes into force it will not be

necessary to design distributaries--see Chapter III, Art. 4--so as to

have a good command when three-fourths full supply is run.

On nearly every distributary there are some watercourses whose command

is bad, and it has been stated (Chapter II, Art. 9) that in an ordinary

unmoduled distributary the sizes of the outlets in such cases should be

extremely liberal. To module any such outlet would cause a lowering of

the water level in the watercourse and would interfere with the

irrigation. Such outlets should not be moduled. Again, there are some

few outlets which are not submerged, _i.e._, there is a free fall into

the watercourse. The discharge does not depend on the water level in the

watercourse, and it is not affected by any enlargement or clearance of

it. It depends only on the water level in the distributary. This water

level, if most of the outlets are moduled, will be fairly constant. Such

outlets need not be moduled, and they should not be moduled unless the

other unmoduled outlets in the reach concerned are sufficiently

numerous, and perhaps not even then, because moduling involves some

expense.

A distributary generally has some falls which divide it into reaches.

Immediately upstream of a fall the water level for a given discharge is

not affected by the silting or scouring of the channel. Any outlets near

to and upstream of the fall are less subject than others to variation in

discharge, and are suitable for non-moduling in case a sufficient number

of unmoduled outlets is not otherwise obtainable.

Regarding the watercourses at the extreme tail of a distributary it has

been pointed out (Chapter III., Art. 7) that in an ordinary case they

should not be left without masonry outlets, because they may then lower

the water level and so unfairly reduce the supply of any watercourse,

even though upstream of them, which has such an outlet. But any outlets

near the tail of a distributary can suitably be left unmoduled because

of the difficulty of ensuring that the supply at the tail shall be

exactly what is needed.

Gibb’s modules have been tried on various distributaries in the Punjab

and found to give good results. It is believed however that in only one

case has a whole distributary been moduled. The distributary is a large

one, its length being 35 miles. It appears that the discharge reaching

the tail of the distributary is not constant but varies, as was to be

expected, when the head discharge varies for any length of time. The

command on the distributary is good. There is nothing to show that

matters would not have been improved, and money saved, by leaving some

of the outlets without modules.

It has been remarked above, that at the downstream end of a reach ending

in a fall, the F.S. level of a distributary is not affected by silt. At

the upstream end of the reach it is affected. There are thus two

gradients, one flat, and one steep. It appears to have been decided in

one case in the Punjab, that the minimum limit of supply for the module

should be about half an inch below the flat line and the maximum limit

·3 feet above the steep line. In many cases a greater range would be

required,[55] say a foot.

[55] It is understood that a range of a foot can easily be arranged

for, and that ranges of 3 or 4 feet can be introduced at slightly

increased cost.

In Chapter III. Art. 7, the case of a distributary without modules but

with the outlets carefully adjusted, was considered. The question to be

decided in each case is whether such an arrangement is preferable to

moduling some of the outlets. This turns largely on the amount of

attention which would be bestowed on the case. In view of the difficulty

of securing such attention and of the trouble of constantly making

alterations in a certain number of outlets, it is probable that moduling

will in many cases be considered preferable.

The question of moduling the heads of distributaries has also been

considered in the Punjab. For minor or small distributaries modules are

feasible. For a large distributary a module would be expensive and it

appears that the present system of regulating is preferable.

Kennedy’s “Gauge Outlet,” which is a kind of semi-module is described in

Appendix K. It is being tried in the Punjab.

APPENDICES.

APPENDIX A.

DIVIDE WALL ON LOWER CHENAB CANAL.

(See page 50, first footnote.)

[Illustration: FIG. 27.]

The Gagera branch of the Lower Chenab Canal--the left-hand branch in

fig. 27--was found to silt. It was proposed to make a divide wall (fig.

27) extending up to full supply level. The idea is unintelligible. The

silt does not travel by itself but is carried or rolled by the water. As

long as water entered the Gagera branch, silt would go with it. The

authorities, who had apparently accepted the proposal, altered the

estimate when they received it, and ordered the wall to be made as shown

dotted and of only half the height. This was done. The idea seems to

have been that the wall would act as a sill and stop rolling silt. This

is intelligible, but such sills do not always have much effect on

rolling silt. Moreover, there was a large gap, A B, in the wall. The

work is said to have proved useless, and proposals have been made to

continue the wall from A to B. In this form it is conceivable that it

may be of use.

APPENDIX B.

SPECIFICATION FOR MAINTENANCE OF CHANNELS.

(See page 138.)

I. ROADS AND BANKS.

1. =Filling Holes.=--Holes to be all dug out and thoroughly opened and

inspected, then to be filled in with rammed earth. Never to be filled in

a hurry or without digging out.

2. =Dressing.=--Heavy soil to be dressed even. Light sandy soil to be

disturbed as little as possible, and grass in such soil not to be

removed except when in large tufts. When dressing is done, the road to

be given (as far as possible) a transverse slope from the canal side of

about 1 in 50.

3. =Trees.=--Branches to be lopped so as not to obstruct riders. Great

care is needed to see that the men do not lop needlessly high. Roots, if

projecting on road, to be covered up or cut out.

4. =Petty Repairs.=--Settlement or wearing down, if slight, should be

made good on maintenance estimates, otherwise on special estimates.

Cracks should be dug out and filled in and rammed. Old “dead men” or

walls of earth should be utilised or at least levelled down.

5. =Sand or “Reh” Soil.=--Can be dug out to a depth of 9 inches and

removed to a distance, and (the places having been inspected by the

Subdivisional Officer) replaced by good soil got from pits or berms, the

places being selected with care. If the lead is slightly askew, the

stuff removed can be put in the same pits from which earth is got.

6. =Laying long coarse Grass on Road.=--This can be done in cases where

the removal of sand or “reh” is not practicable or has proved

ineffective. The grass is laid crosswise to prevent wheels sinking in.

II. JUNGLE AND TREES.

1. =Jungle.=--To be cut close to the ground or to be dug out by the

roots when ordered. To be burned as soon as dry. Dead branches, twigs,

etc., to be burned or removed to rest-houses, and not left about on

canal land. Precautions to be taken against damage by fire to forests,

etc. Clearance to include the channel[56] and both roads, and any jungle

on the slopes of the spoil which obstructs the roads.[57]

[56] Jungle on inside slopes not to be cleared where banks fall in or

where channel is too wide.

[57] When an embankment runs parallel to an inundation canal, a chain

or so distant, the intervening space need not be cleared, nor need the

top of a bank be cleared if it is so uneven that it is not a road.

2. =Trees.=--Trees which fall into a channel or across a road to have

their branches cut away at once. The trunk to be removed so far as is

possible. Trees which are dead or broken off should be felled, also

those which have been blown into inclined positions, unless bad gaps

will be caused. Trees (unless required for stock) to be sold as they lie

and removed, including the parts below ground, by purchasers, within a

fixed time. Logs, etc., not to be left lying about on canal land.

Stumps, etc., to be made into charcoal and the holes filled up.

_Note._--The above works (Parts I. and II.) to be done immediately after

the rains (repairs to roads and removal of trees, branches, etc., being

also done during the rains or whenever necessary) and finished at latest

by 31st October.

III. CATTLE CROSSINGS OR GHÁTS.

1. =Repairs.=--Gháts to be dressed, strengthened, and kept neat, the

bank being thrown back and curved so as to give a long inner slope, and

lumps, etc., levelled off.

2. =Closures.=--To be closed (by order of Subdivisional Officer and no

one of lower rank) only when very near to a bridge or near to another

ghát.[58] If closed, to be staked up and bushing to be added. Not to be

closed by loose thorny branches. Not to be allowed close to any

milestone, outlet, etc.

[58] Regarding gháts at bridges, see Chap. II., Art. 12.

3. =Small Gháts.=--Gháts where only foot-passengers cross, can run

diagonally up the slopes or as may be convenient. They should be dressed

and kept in order.

4. =Canal Road at Gháts.=--At all gháts care must be taken that the

canal road, especially if used for driving, is not cut up and is kept in

proper order.

IV. MISCELLANEOUS ITEMS.

1. =Rubbish or Obstructions in Bed of Channel.=--To be removed from the

channel when it is laid dry, and not left till it is about to be

reopened.[59] Old stakes, etc., to be sawn off when crooked or too high.

[59] Where the bed is too low, no rubbish clearance should be done

except in the case of very large snags, etc.

2. =Temporary Aqueducts or Damaged Wooden Bridges.=[60]--To be removed

before water is expected (but not sooner than is necessary) and the

banks repaired and made good.

[60] This applies to inundation canals.

APPENDIX C.

SPECIFICATION FOR MAINTENANCE OF MASONRY WORKS.

(See page 138.)

1. =General Repairs.=--Masonry, plaster, pitching, etc., to be kept in

repair. Pitching, where defective or out of line, to be made right.

Bumping posts to be fixed in proper positions. Earth to be added to

ramps, etc., where needed. Metalling to be regularly seen to. Needles,

planks, hooks, railings, winches, lamp-posts, lamps, etc., to be kept in

order and complete. Bricks, bats, etc., to be properly stacked. Needles,

etc., to be neatly stacked on rests or with bricks under them. All

surplus and useless needles, etc., to be removed. Huts to be kept in

repair. Extra mud walls or screens not to be allowed when unsightly. All

verandah openings to be edged with a 6-inch band of whitewash.

2. =Jungle.=--All masonry to be kept free from jungle growth, and all

piers free from caught jungle. For this purpose long bamboo weed-hooks

to be supplied.

3. =Dressing, etc.=--Rubbish, lumps of earth, logs, etc., to be cleared

away, pits and holes filled up. Banks, slopes, etc., of main and branch

channels in the neighbourhood of the work to be specially levelled and

dressed.

_Note._--All works should be specially seen to in October, and

everything be in order by 31st October.

APPENDIX D.

WATCHING AND PROTECTING BANKS AND EMBANKMENTS.[61]

(See page 138.)

[61] This is reprinted from _Punjab Rivers and Works_. It was drawn up

for inundation canals and flood embankments.

1. =Watching.=--Every watchman employed to have a fixed headquarters and

a fixed beat. If there is no permanent hut on or near the bank, grass

huts should be erected by the men at the places fixed. The presence or

absence of the men to be frequently tested by the mate and suboverseer.

The suboverseers tests to be recorded in a book and to form the subject

of frequent inquiry by the Subdivisional Officer, who will also record

his remarks and take proper action in case the suboverseer is in fault.

2. =Gauge Readers, Regulating Establishment, Bungalow Watchmen,

etc.=--To be made to assist whenever possible. The allotment of a beat

to each such man has been separately ordered.

3. =Employment of Men on Repairs.=--The men, when not otherwise

occupied, to do petty repairs, etc., within their beats, but not to be

put on miscellaneous duties and sent about as messengers, nor to act as

orderlies or khalassies.

4. =Strength of Establishment.=--Should generally be greater for one

and a half months in July and August than at other times. Care to be

taken as to this and as to dismissing men when no longer needed.

5. =Stakes and Mallets.=--To be collected beforehand, if necessary, at

suitable places, to be accounted for at end of flow season and balance

taken care of.

6. =Breaches.=--The Establishment to be trained by the Subdivisional

Officer to report every breach to all officials with the greatest

possible speed. The mate, daroga, and suboverseer to remain there till

the breach is closed and to promptly send a report on the prescribed

form to the Subdivisional Officer.

7. =Serious Breaches.=--In case of serious breaches of main channels the

Subdivisional Officer to himself reach the spot as soon as possible.

8. =Breach Reports.=--See printed form M[62] attached. To be promptly

submitted for each breach to the Executive Engineer. The report contains

a column for cost of closure. This means the stoppage of the flow and

not the complete making up of the banks. The column for remarks of the

Executive Engineer should be filled in and the report promptly returned

to the Subdivisional Officer, who will, in the meantime, be making up

the banks and preparing a requisition or estimate.

[62] Not printed.

9. =Progress Report.=--With the Executive Engineer’s monthly progress

report a list of breaches will be submitted, canal by canal, with

columns showing date of occurrence and cost of closure. The return

should be on the attached form G.[63] The Subdivisional Officer should

also submit this form to the Executive Engineer.

[63] Not printed. The form differs slightly from a form prescribed by

the Chief Engineer for general use in the Province.

10. =Estimates.=--The cost of breaches is not to be charged to

maintenance estimates. At the close of each month the Executive Engineer

should submit or sanction an estimate, accompanied by the breach

reports, for closing any breaches which have occurred and making up the

banks.

11. =Breaches in the Flooded Area near Canal Heads.=--These may be of

special importance. It may be impossible to do any good and money may be

uselessly spent. In any such cases the Subdivisional Officer should at

once proceed to the spot and the case should be reported by wire to the

Executive Engineer and, if necessary, to the Superintending Engineer.

12. =Breaches in Flood Embankments.=--The Subdivisional Officer must at

once proceed to the spot and the case be reported by wire to the

Executive Engineer and Superintending Engineer. The Breach Report forms

can be submitted partially filled in at the earliest possible moment and

a complete form afterwards.

APPENDIX E.

SPECIFICATION FOR BUSHING.

(See page 139.)

1. The object of bushing is to form a silt berm and thus prevent or stop

the falling in of the banks.

2. The branches must be thickly packed in order that the water among

them may become still, and also in order that they may not be shifted by

the stream. If thickly packed, the pegs required will also be fewer.

Most of the branches should be leafy and freshly cut, but, mixed with

these, there may be a proportion of kikar or other leafless branches.

Frequently it is possible to utilise jungle trees of small value,

bushes, scrub jungle, or even long grass.

3. Except when the bushes are to be very small or the length to be

bushed very short, the proposed line for the edge of the berm should be

marked out by long stakes driven in the water at fairly close intervals.

Otherwise the work may be badly done and the berm formed imperfect and

out of line.

4. As the berm formed is not likely in any case to be perfectly

straight, and as subsequent additions to it will be difficult, while

trimming it will be easy, the bushes should extend slightly beyond the

line of the proposed berm. Care should be taken that the lower branches,

which cannot be seen when once submerged, are long enough.

5. The branches should be piled up to above water-level, so that, as

they settle, they will assume the position desired, but to lay them high

above full-supply level on the slopes is useless and wasteful. If the

pegs have to be driven at a high level, the branches should be attached

to them by thin ropes or twine. Long pegs standing up high above the

ground are also wasteful. The pegs should as far as possible be kept in

line and their heads at one level.

6. If bushing is begun during low supply, it need not, at first, extend

up to full-supply level. More branches, freshly cut, can be added as the

supply rises. In any case it is generally necessary to make some

additions to bushing from time to time, and this should be explained to

contractors and others when fixing the rates.

7. If the trees from which branches are cut are in desirable places, the

branches should be cut with judgment; but where trees are in places

where they should not be (_e.g._, on the inside slopes of the channels),

all the branches may be cut off. The trunk may be left temporarily in

order to supply more branches.

APPENDIX F.

ESCAPES.

(See page 9.)

There are no definite rules regarding the capacity of the escapes to be

provided on a canal. On some canals in dry tracts of country the

discharging power of the escapes is a mere fraction of that of the

canal. In other cases it is about half that of the canal. In a district

liable to heavy rain an escape, say at a point where a canal divides

into branches, should be able to discharge about half of the main canal

supply. On branches, escapes, if provided at all, usually discharge into

reservoirs, and their period of working is very limited: it may be only

twenty-four hours.

On distributaries, escapes are seldom provided. It has been suggested,

in connection with modules, that the people irrigating from each

watercourse should be responsible for disposing, by means of it, of a

certain quantity of surplus water. This would be too rigid a rule. On

some watercourses there is much waste land or land under rice

cultivation; in such cases surplus water can be passed off without

damage. The canal subordinates are fully cognisant of such cases, and

they arrange accordingly. In other cases surplus water would do some

damage; but on nearly every distributary the full supply, even when

there is no demand for water, can be got rid of for a few hours, or even

more, without a breach occurring.

Escapes at outlets, in connection with modules, can be arranged by means

of waste weirs or by means of Gregotti’s syphons (_sifoni

autolivelatori_). The following is an abridged translation of part of a

pamphlet by Gregotti:--

The figure represents one of the syphons installed in the “Centrali

Milani.”

A is the supply basin of the “Centrali,” which ends in the syphon B.

The latter is constructed with mouthpiece of rectangular section _a_,

which is submerged in the basin A. A weir divides the mouthpiece of

the syphon from the descending branch, _c_, of the same, also

rectangular in section. The weir crest is at level _dd_, from 2 to 7

cm. below the maximum level of water surface which it is desired not

to exceed in the supply basin.

[Illustration: FIG. 28.]

The descending branch, _c_, has at its base a small tank _e_, which

forms a water seal. The syphon is completed by a tube _f_, which is

attached to the intake branch of the syphon and which ends at a level

of 2 to 7 cm. above the previously mentioned surface _dd_.

As soon as the water surface in the supply basin tends to rise above

the plane _dd_, a filament of water, in falling over the weir _b_,

pours down the descending branch _c_, and when the water has risen

from 2 to 7 cm. above the crest of the weir, the thickness of the

falling stream has become such that it is able, by lapping, with a

wave-like course, the wall _gg_, to extract the air that has become

enclosed in the syphon, and which cannot be replaced because the space

in which the stream acts is closed at its base by the water in the

tank _e_; and at the top also the aeration tube is closed by the rise

in the water surface of the supply basin. From this point the syphon

action quickly becomes fully established and begins to give its full

discharge.

The discharge that is given is equal to that of an orifice in a thin

partition if certain limitations are allowed for between the fall used

in the syphon and the height of the arch, that is, the distance from

the crest of the weir to the inside roof of the syphon.

The discharge is given by the formula

Q = μA√(2_g h_).

Q = discharge of syphon in cubic metres per sec.

μ = a coefficient of reduction of discharge which varies between wide

limits.

A = the minimum cross-sectional area of the syphon in square metres.

_g_ = value of acceleration due to gravity.

_h_ = the fall, or the difference of level in metres between the water

surfaces in the supply basin A and in the small tank _e_.

As soon as the supply basin surface falls, the opening of the aeration

tube becomes uncovered and air is drawn into the syphon. But until the

surface has fallen some centimetres the supply of air is not

sufficient to cause the syphon action to stop completely, and thus the

escape varies gradually from the maximum discharge to zero as the

water surface falls a few centimetres till it reaches its original

level.

In certain cases it is possible to do without the aeration tube,

especially when the fall used in the syphon is not great and when it

is possible to arrange matters so that the velocity of the water

flowing past in front of the syphon is small.

The syphon with a width of 3 metres escapes 8 cubic metres per sec. of

water.

APPENDIX G.

GAUGES.

(See Chap. III., Arts. 2 and 3; also see _Hydraulics_, Chap. VIII., Art.

5, and Appendix H.)

1. The gauge should be placed on that bank and facing in that direction

which enables it to be most conveniently read by the gauge reader and by

officials passing the place.

2. The gauge should be of enamelled iron secured by copper screws to a

post of squared and seasoned wood which is either driven beforehand[64]

into the channel or spiked to a masonry work. Even in the deepest

channel a long enough post can be arranged for. A masonry pillar is not

necessary. The post may be rectangular in cross-section, with upstream

and downstream edges cut sharp. This prevents, or greatly reduces, the

heaping up of water at the upstream side and the formation of a hollow

downstream. If the “Ward” gauge of two vertical planks is used, the

planks should meet at an acute angle, not a right angle, and not be

wider than 7 inches each.

[64] Driving after the gauge is attached may loosen or break the

screws.

3. The top of the gauge should be slightly above the highest probable

water-level. The post should extend up to the top of the gauge.

4. If ever the graded bed of the channel is altered the zero of the

gauge should be altered. There may be some risk of confusion at first,

but it can be avoided by exercising due care and making notes. The

levels of the old and new zeros should be recorded.

5. A gauge at a distance from the bank is objectionable. It collects

jungle, cannot be properly read, and is liable to be damaged by floating

logs or boats. A gauge should be as near as possible to one bank or the

other. If the bank is vertical, the gauge should be quite close to it.

If, owing to silt deposit, the gauge is dry at low supply, the deposit

can be removed by the gauge reader.

6. Every regulator should be given a name, generally that of a

neighbouring village and not that of a channel, and the gauge book

headings should be drawn up in an intelligent and systematic manner.

Each main channel should be entered in order, and each regulator on the

channel--together with the head gauges of all channels which take off

there--should be entered, commencing from upstream. A specimen is given

on page 109. Thus the head gauge of any branch appears in the register

of the main channel from which it takes off, other gauges on the branch

appearing in the register for the branch. And similarly as regards a

distributary which has gauges other than the head gauge.

7. Each gauge reader should be supplied with a register, each page

having, besides the counterfoil, as many detachable slips--marked off by

perforations--as there are officials--usually the Subdivisional Officer,

zilladar and suboverseer--to whom daily gauge reports are to be sent.

The titles and addresses of these officials are printed on the backs of

the respective slips. The slips and counterfoil have printed on them a

form--similar to part of the specimen shown on page 109--showing the

names of all the gauges read by that particular gauge reader, so that

he has merely to fill in the date and readings, tear off the slips and

despatch them. The posting of the register in the subdivision is

facilitated if each gauge has a number and if the corresponding numbers

are printed--besides the names--on the gauge slips. If the gauge reader

does not know English, the headings of the slips are printed in the

vernacular. If the gauge readings are telegraphed, there may be only one

slip--besides the counterfoil--which is sent to the telegraph

signaller.

APPENDIX H.

GIBB’S MODULE.[65]

(See p. 164.)

[65] This description has been supplied by Glenfield & Kennedy,

Kilmarnock. The modules can, it is understood, be obtained from them.

The attributes of a perfect module are many and varied, but in Gibb’s

module they have all been successfully embodied in what is probably the

simplest piece of apparatus of its kind ever devised. The following

summary of the characteristics of Gibb’s module is, therefore,

equivalent to an enumeration of the attributes of a perfect module:--

Gibb’s module

Cannot be tampered with, }

Cannot get out of order, } since it has no moving

Silt or other solid matter in the water } parts, and because of its

cannot affect its action, } extreme simplicity.

Requires no attention, }

It is accurate, } being designed on scientific

Works with very small loss of head, } hydraulic principles.

It is portable, and can be erected at any desired site very simply and

easily.

It is strong and durable.

The range of variation of both up- and downstream water-levels through

which the discharge remains constant is more than sufficient to meet

all the requirements of irrigation canals.

The sufficiency of the delivery can be ascertained at a glance.

The water can be drawn from any desired depth in the parent channel.

When desired, means are provided whereby the supply can be closed or

opened at will.

Means are provided, if desired, for a sudden increase of discharge

when the upstream water-level exceeds a certain limit, so that surplus

water, which might endanger the safety of the canal, is allowed to

escape into the branch whenever the danger limit is reached. The

upstream water-level at which escapement begins can be fixed in

accordance with the requirements of each site, and the action of the

escape notch is independent of the opening and closing of the module.

No designing or calculations are required. These have already been

worked out. Known the discharge required, the module is supplied

complete and ready for setting in position in the canal bank.

HYDRAULIC PRINCIPLE.

The entire absence of moving parts is the chief feature of Gibb’s

module; the water simply regulates itself by using up all the excess of

energy over and above that required to discharge the correct supply of

water. The way in which this takes place will be understood from the

following analogy:--

We all know that when we stir tea in a cup so as to make it spin, the

liquid rises at the rim of the cup and curves down into a depression in

the middle, and the greater the spin the more marked this effect is. It

is, we know, the centrifugal force produced by the spin that makes the

tea remain high at the rim of the cup. If, while the tea is thus

spinning, a teaspoon is held so that it dips slightly below the surface

of the liquid near the rim, it will obstruct the flow of the outer

portion of the liquid, which will fall in towards the depression in the

middle. The reason for this, of course, is that the centrifugal force is

absorbed when we interrupt any part of the spin with the teaspoon; hence

the liquid must fall, and we know that when liquid falls it uses up

“head” or energy.

In Gibb’s module a similar action is made to take place in a steel

chamber, semicircular or spiral in plan, through which the water flows

in a semicircular path instead of circulating round and round as in the

teacup. The surface of the stream, however, assumes the same form as it

does in a cup, because it flows under the same conditions. Across the

chamber are fixed a number of vertical steel diaphragm plates which take

the place of the teaspoon in the above analogy. The lower edges of these

plates are of such a shape, and they are fixed at such a height from the

bottom of the chamber, as to allow a stream of just the correct required

discharge of water to flow under them without interference. But if,

owing to an increase of head caused by a rise in the upstream

water-level, the water tends to rise higher at the circumference of the

chamber, then the water at the surface of the stream strikes against the

diaphragm plates, and its centrifugal force being absorbed, it will fall

in towards the centre just as happened in the teacup when the spoon was

used in place of these plates. In this way the excess head that caused

the additional rise of water at the circumference is used up by the fall

back towards the centre. The full capacity of the semicircle or spiral

for using up excess head or energy in this way is made available by the

use of a sufficient number of diaphragm plates fixed at suitable

intervals. When the range of head to be dealt with is not large, then a

semicircular chamber is sufficient; but for large ranges of head the

chamber is made of spiral form so as to lead the water round a complete

revolution or more, as may be necessary.

STRUCTURAL DETAILS.

Fig. 29 shows the general form and structure of the type of module

suitable for irrigation. Fig. 30 is from a photograph.

The working chamber or shell A is constructed of mild steel plating

securely riveted to a framework of angle steel, and the semicircular

form of the shell with the rigid diaphragm plates B B riveted to the

walls makes a very strong structure, and ensures durability.

The “leading-in” bend C is of cast iron strongly bolted to the steel

shell, and is so designed as to deliver the water into the module

chamber in a completely established vortex condition.

The socket D on this “leading-in” bend is made so as to allow of

considerable latitude in the vertical alignment of the straight

leading-in pipe, so that the water can be drawn from any desired depth

in the parent channel, and the proportion of silt drawn off is thus

brought under control.

[Illustration: -- END ELEVATION. --

-- PLAN. --

-- FRONT ELEVATION. --

FIG. 29.--Details of Gibb’s Patent Module.]

Grooves E E and a shutter F, as illustrated, for closing off the flow

through the module, are provided, if required, but all modules are not

fitted in this way, because many irrigation authorities consider it

undesirable to provide the consumers with unrestricted facilities for

closing off their supplies without previously giving notice of such an

action.

[Illustration: FIG. 30.--The Completed Module (Open Type for Low

Heads).]

An escape notch H is provided in the position indicated when desired. It

may, however, be found difficult to determine beforehand the upstream

water-level at which it is necessary to allow this escape of surplus

supply, so that it is generally more satisfactory to cut the escape

notch after the modules have been installed and actual experience has

indicated a suitable level for the notch crest.

In the standard type of module for irrigation purposes the top of the

module chamber is completely open, as shown, and this is the type

generally recommended, as it is found that consumers have greater

confidence in an apparatus which hides nothing from them. To meet the

needs of special cases, however, a second type is also made in which the

chamber is completely closed and considerably reduced in height, being

thus specially suitable for sites where space is confined.

Pipes I, of diameter suitable for all sizes of modules, are also

supplied. These may either be welded steel or cast iron, as desired. An

18-feet length of pipe is usually found sufficient to bring the supply

through the canal bank to the module.

All modules supplied are treated with anti-corrosive paint, which

ensures the protection of the metal.

APPENDIX K.

KENNEDY’S GAUGE OUTLET.[66]

(See p. 168.)

[66] See _Punjab Irrigation Branch Paper No. 12_, “Results of Tests of

Kennedy’s Gauge Outlet.”

FIG. 31 shows a bell-mouthed orifice discharging into an air-space. The

jet springs across the air-space and traverses a gradually diverging

tube. Let _a_, A be the sectional areas of the stream at the air-space

and the downstream end of the tube respectively, and let V, _v_, and

P_ₐ_, P₁ be the corresponding velocities and pressures. Let resistances

be neglected. Since the pressure in the air-space is P_ₐ_,

V = √(2_g h_₀)

or the discharge through the tube depends only on _h_₀ and not on _h_₁.

[Illustration: FIG. 31.]

By Bernouilli’s theorem,

V² P_ₐ_ _v_² P₁

---- + ---- = ----- + --

2_g_ W 2_g_ W

P₁ - P_ₐ_ V² - _v_²

--------- = ---------.

W 2_g_

This quantity (since _v_ is small) is not much less than _h_₀ or

V²/2_g_. In other words, the water levels of two cisterns with an

air-space between them differ only a little, or _h_₁ is small.

The above case (two cisterns and air-space) is mentioned in

_Hydraulics_, Chap. V. The principle is simply that the velocity head at

the air-space is reconverted into pressure head by passing the stream

through a gradually diverging tube. In the absence of such a tube the

velocity head would be wasted by causing eddies in the downstream

cistern.

If the downstream cistern is a watercourse whose water-level is

considerably lower than that of the upstream cistern or distributary, V

is obviously unaffected. Also P₁ is obviously reduced. Therefore, by

Bernouilli, _v_ is increased, or the stream does not fill the expanded

tube and there are eddies in the tube. The water-level in the

watercourse may even be lower than the end of the tube. The discharge is

unaffected.

In practice there are, of course, resistances, but this fact does not

affect the general conclusions stated above. The minimum working head

(difference between the two water-levels) which gives a constant

discharge is greater than would be the case in the absence of

resistances. This “minimum working head for modularity” has been found

to be ·21 foot, ·42 foot, and ·61 foot, the corresponding values of the

“depression,” _h_₀, being respectively 1 foot, 2 feet, and 3 feet. When

the working head is less than the above, the discharge is less and it

depends on the working head. The depression should, according to

Kennedy, be about 1·75 feet, but it may be more.

The chief difficulty in using the gauge outlet as a module is that the

air vent can be stopped up. This converts the apparatus into a compound

diverging tube (_Hydraulics_, Chap. III., Art. 17). The discharge is, of

course, increased, and it becomes dependent at all times on the working

head. Another difficulty is that any rise or fall in the water-level of

the distributary (and such rises and falls may occur owing to silting or

scour, however carefully the discharge may be regulated) alters the

discharge somewhat, though not to the same degree as in an ordinary

outlet with a working head of, say, ·5 foot. In short, Kennedy’s gauge

outlet, or “semi-module” as it is sometimes called, can modify but not

do away with the variations of the discharges of outlets.

INDEX.

Absorption, 16, 159.

Alignment, principles of, 4.

Alignment, centrality in, 5.

Alteration in line, 59.

Assiut Barrage, 11.

Assouan Dam, 11.

Banks, construction of, 138.

-- protection of, 139, 175, 178.

-- width and height of, 56.

Banks and Roads, 53.

Basin Irrigation, 11.

Berms, 53.

Bifurcations, 47.

Bifurcation, head needed at, 45.

Borrow pits, 55.

Branches of Canals, 3.

Breaches in Banks, 176.

Bricks used for canal work in India, 88.

Bridges, 8, 80, 87, 130.

-- Skew, 29, 42.

Bushing of banks, 178.

Canal and branches, 20, 47.

Canal, bed width of, 51.

-- supplied from reservoirs, 3, 13.

-- inundation, 1, 45, 79, 127, 156.

-- perennial, 1.

Capillarity, 16.

Cattle Gháts, 81, 173.

Cement for lining channels, 160.

Chainage, 93, 118.

Channels, alterations in, 97.

-- enlargement of, 97, 139.

-- gradients of, 50.

-- side slopes of, 52.

Colonization Schemes, 64.

Command, 2.

Commanded area, 4.

Contour lines, 37.

-- plan, 26, 36, 63.

-- survey, 37.

Crops, failure of, 103, 142.

-- kinds of, 101.

Culturable commanded area, 26, 113.

Curves and bends in channels, 8, 139.

“Delta,” 22, 110.

Deputy Collector, 96.

Designs and Estimates, 60.

Design of canals, 2, 26, 30, 47, 147, 156.

Discharge of canal during rabi, 52, 118.

Discharge observations, 107.

Discharges of Punjab rivers, 145, 157.

Discharge tables, 106.

-- through an outlet, 61.

Distance marks, 93.

Distribution of water, 14, 118, 125.

Distributaries, 3, 20, 44, 46.

-- best system of, 71.

Distributary, bed width of, 68.

-- design of, 60.

-- height and width of banks, 68.

-- kharif, 156.

-- longitudinal section of, 69.

-- major and minor, 41.

-- off-take of, 51.

-- remodelling of, 128.

-- side slopes of, 69.

-- strip of land for, 69.

-- with three fourths full supply, 45, 68, 166.

Divide Walls, 33, 169.

Divisions, canal, 96.

Drainage, 10.

Drainage Crossings, 8, 156.

Duty of water, 21, 25, 39, 148, 153, 154.

Duty, improvement of, 24, 102, 158.

Eastern Jumna Canal, 31.

Efflorescence called “Reh,” 15.

Egypt, irrigation in, 11.

Embankments, 9, 33, 156.

Escapes, 9, 100, 180.

Estimates for work, 59.

Evaporation, 16.

Executive Engineer, 96.

Extensions of canals, 127.

Extra land, 58.

Falling Shutters, 32.

Falls, 8, 81, 87.

-- incomplete, 87, 130.

-- notch, 86.

Field book, 101.

-- map, 101.

-- register, 101.

Final line, 59.

Flow and lift, 11.

Full supply duty, 64.

Full supply factor, 64.

Ganges Canal, 31.

Gauges, 10, 103, 104, 183.

Gauge reader, 96, 98, 105, 184.

Gauge reading, 105, 121.

-- register, 105, 106, 108, 111.

Gibb’s module, 164, 186.

Guide banks, 35.

Head for distributary, 82, 83.

Headworks, 2, 30, 98, 99, 137.

Indents for water, 98, 108, 110.

Inundation canals, 1, 45, 79, 127, 156.

Irrigation boundaries, 33, 129.

-- in various countries, 1.

-- registers, 113.

-- unauthorised, 101.

Kennedy’s gauge outlet, 168, 193.

-- Rules for channel design, 48.

Kharif or Summer Crop, 23.

Kutter’s co-efficients, 51.

Lift irrigation, 11, 142.

Lime for making channels watertight, 162.

Longitudinal section, 69, 130.

Losses of water in channels, 16, 38, 159.

Low supplies, 118, 123.

Lower Chenab Canal, 25, 144.

Lower Egypt, 11.

Lower Jhelum Canal, 144.

Maintenance work, 138, 171, 174.

Marginal Embankments, 9.

Masonry works, 29, 80, 89.

-- -- large scale site plan, 89.

-- -- type designs, 89.

Mills, 8.

Minors, question of desirability of, 75.

Modules, 162, 186.

Navigation, 12.

Needles and horizontal planks, 85.

Oil for lining channels, 160.

Older Indian canals, 10, 68, 98.

Outlet, discharge of, 61.

-- registers, 113.

Outlets, 15, 61, 66, 67.

-- applications regarding, 140.

-- design of, 76.

-- on inundation canals, 79.

-- on older canals, 68.

-- positions of, 65.

-- remodelling of, 131.

-- register of, 113.

-- size of, 114, 134.

-- temporary, 78.

-- variability of duty on, 66.

Parapets, width between, 77.

Patwari, 96, 101.

Percolation, 16.

Perennial Canals, 1.

Pitching, 90.

Plan, large scale, 59.

Postal system, 97.

Profile walls, 91, 94.

Project, sketch of, 26.

Proportion of land to be irrigated, 27, 156.

Puddle for lining channels, 160.

Punjab, projects for canals in, 144.

Punjab rivers, 145, 147.

Quarters for regulating staff, 88.

Rabi or winter crop, 23.

Railings, 88.

Rain, 9, 22, 100.

Ramps, 88.

Ratio of bed width to depth, 50.

Reduction in size of channel, 128.

Registers, irrigation, 113.

Regulation of supply, 103, 121, 127.

Regulators, 7, 80, 84, 184.

-- permissible heading up, 85.

Remodellings of channels, 127.

-- of outlets and watercourses, 131, 134.

Rest Houses, 95.

Reservoirs, 13.

Rules for designing canals, Kennedy’s, 48.

Scheme, cost of, 28, 59.

Sides, falling in of, 139.

Sidhnai canal minors, 41.

Silt, clearance of, 97, 138, 139.

-- deposit, 15, 97.

-- trapping at Headworks, 47.

Silting and scouring, 15, 48, 98, 139.

Sirhind Canal, 19, 144.

-- -- silting in the head reach of, 98.

Soil, water-logging of, 10, 24, 102.

Spoil Banks, 52, 57.

Subdivisions, canal, 95.

Subdivisional officer, 96.

Suboverseer, 96.

Superintending Engineer, 96.

Supply carried, 100.

-- distribution of, 14, 118.

-- mean and full, 27, 46, 122.

-- regulation of, 103, 104, 106, 127.

Syphons, 7, 71, 87, 181.

Tailing of one channel into another, 40.

Telegraph, line of, 97.

Training of rivers, 33.

Trial lines, 58.

Trial pits, 58.

Triple canal project, 144.

Tunnels, 13.

Turns, or rotational periods of flow, 14, 118.

Type cross sections, 56.

Under-sluices, 32.

Upper Bari Doab Canal, 19, 144.

-- Chenab Canal, 33, 144.

-- Egypt, 11.

Upper Jhelum Canal, 50, 144.

Velocity, 12, 50.

Village lands, 62.

Watching banks, 175.

Water, payment for, 12, 100, 102, 142, 143.

Water level, fluctuation in, 100, 124.

Watercourse, limit of size of, 74.

Watercourses, 4, 20, 65.

-- applications regarding, 140.

-- for trees, 58.

-- remodelling of, 131.

-- with poor command, 67, 133, 166.

Waterings, 11, 24.

Water-logging of the soil, 10, 24, 102.

Wave, travel of, down a channel, 124.

Western America, canals in, 12.

-- Jumna Canal, 31, 39.

Wing Walls, 89.

Works, arrangement of, 89.

-- two or more close together, 89.

-- urgent repairs of, 137.

Zilladar, 96.

Harvey & Healing, Printers, Manchester Street, Cheltenham.

Transcriber’s Notes

The inconsistent use of periods after Roman numerals has been

retained; other inconsistencies (spelling, hyphenation, formatting and

lay-out) have been retained as well, except when mentioned below.

Depending on the hard- and software used and their settings, not all

elements may display as intended. Some of the tables are best viewed

in a wide window.

Page 21: The equation does not agree with the calculations given.

Page 66, Fig. 11: There are two illustrations labelled Fig. 11, the

hyperlinks point to the appropriate illustration.

Changes made

Obvious typographical errors have been corrected silently. Footnotes

and illustrations have been moved out of text paragraphs. Some tables

have been re-arranged or split; in several tables, the data alignment

has been standardised.

Page 18, table, Total of second column: 8·93 changed to 8·01

Page 39: Kutters changed to Kutter’s

Page 93: marked out changed to marked at

Page 69: 3 Depth of digging changed to 13. Depth of digging

Page 109, first average ·1 changed to 4·1

Page 117: Net Areas Irrigated in Areas changed to Net Areas Irrigated

in Acres

Page 150: Cusecs. added as in similar tables

Index: Cattle Ghats changed to Cattle Gháts; Line for making ...

changed to Lime for making ...; Lower Chenal Canal changed to Lower

Chenab Canal.

A Subdivisional Officer generally receives a steady stream of