UNITED NATIONS

ECONOMIC COMMISSION FOR ASIA AND THE FAR EAST FLOOD CONTROL JOURNAL

ST/ECAFE/SER.C/17 December 1953

CONTENTS

Page

The Bureau of Flood Control and Water Resources Development .... 3

I. Semi-autonomous bodies to administer projects ...... 4

II. Equipment and programme of hydraulic laboratories ...... 7

India

Hydraulic Research Station, Krishnarajasagar, Mysore . . 7

Pakistan

Hydraulic Research Laboratory, Dacca, East Bengal .... 8

Hydro-Dynamic Research Station, Hyderabad, Sind ...... 10

III. Estimating maximum flood...... 12

IV. Progress in rainmaking research in Australia ...... • 13

V. Atomic probe for soil moisture measurement ...... 18

VI. Regional projects

Hong Kong

Proposed irrigation schemes in the Nev; Territories . . . 19

India

Lifting dam across river Tunga in Mysore State ...... 27

The Walayar Irrigation Project ...... 37 - 2 -

CONTENTS (cont'd)

Page India ( cont1d)

The Mangalam Project ...... 41

The Mayurakshi Project...... 42

The Chalakudy river development ...... 44

The Mudki-Golewala distributary system ...... 47

The lift irrigation scheme ...... 49

The progress of the Damodar Valley Corporation ...... 50

The Poringalkuthu Hydro-Electric Scheme ...... 56

Nepal

Plan for the development of Nepal ...... 60

Pakistan

Development plan for the Baluchistan States...... 61

The Karnafuli Hydro-Electric Project ...... 63

Underground water reservoirs ...... 64

The Ganges-Kobadek Scheme ...... 64

The Taunsa Project ...... 65

The Gilghit Projects ...... 65

Repairs to the Lloyds Barrage ...... 66

New canal for the Punjab planned ...... 66

Two irrigation projects for the Punjab approved .... 66

Philippines

The Padada River Irrigation Project ...... 66

VII. Projects outsdie the region

The Paraiba-Pirai Diversion (Brazil)...... 69

The Kansas River Flood-Way Plan (United States of America) 73 - 3 -

Bureau of Flood Control and Water Resources Development

The Bureau of Flood Control of the United

Nations Economic Commission for Asia and the Far East

will henceforth be known as the Bureau of Flood Control

and Water Resources Development of the United Nations

Economic Commission for Asia and the Far East. - 4 -

I. SEMI-AUTONOMOUS BODIES TO ADMINISTER PROJECTS1/

The Rao Committee which inquired into the administration of the Damodar Valley Project (India) has strongly supported the system of semi-autonomous corporations for administering multiple-purpose projects.

"It is the best method yet devised" it says "of executing multiple-purpose projects efficiently and economically; where it has failed to achieve results, it is more because of the defects in the personnel of the corporation or of the government departments or both than anything inherent in the concept of the corporation itself".

The committee also says: "The acceptance of the corporation idea implies removal of treasury control and checks imposed by civil service regulations. It also means limitation of the authority of the government and parliament in respect of matters which are dealt with finally by the statutory corporation".

according to the Rao Committee, the duties and powers of a corporation should be as follows:

(1) A corporation should be created only when a project has been investigated

in sufficient detail, and a fairly firm estimate has been sanctioned by the government.

(2) Within the sanctioned project estimate, the corporation should have full

power to execute the project, without any outside interference. It should not have any power to modify the scope of the project. That power should vest only in the government.

(3) If the project estimate is likely to be substantially exceeded, the

corporation must come to the government for revised sanction.

(4) After complotion of the project the corporation should have full

powers to run its commercial or quasi-commercial activities, irrigation,

navigation, power and flood control.

/(5) In regard to

1/ Abstracted from an article in Hindustan Times, 24 July 1953 - 5 -

(5) In regard to non-commercial activities like soil conservation,

afforestation, etc., schemes should be submitted by the corporation to the government for approval before they arc taken up. Such schemes should be implementated only to the extent approved by the government.

(6) The budget estimates of the corporation should be subject to government

approval.

(7) Power should be taken by the government to give directions "as to the

exercise and performance by the corporation of its functions" somewhat on the lines of the air Corporations act, 1953.

(8) The powers reserved for the government under these proposals should

vest in the Central Government, as it would obviously be impossible for a corporation to consult different governments, which might give different decisions.

In other respects, the scheme of the Damodar Valley Corporation (DVC) may be followed.

The committee says: "The Estimates Committee has recommended that full parliamentary control over the various river valley schemes should be ensured; that all the plans relating to a scheme should be laid before parliament as soon as the scheme is sanctioned, together with an explanatory memorandum, and that changes in the plans or estimates should be got approved by parliament after they are first examined by the committee. We are unable to agree with these suggestions in so far as statutory corporations are concerned, as they would have the effect of placing them in a position worse than that of government departments".

/Referring to - 6 -

Referring to the DVC Act, the Rao Committee does not agree with its provision that "the members of the Corporation shall be appointed after consultation with the State Governments." It says: "be do not consider it a sound principle to provide for regional representatives or corporations of this nature." The committee, similarly, is opposed to part-time members of corporations who make difficult the holding of frequent meetings of the corporations. It would reduce the strength of a corporation to the chairman and two members. Although the committee would not prescribe the qualifications of the members by statute, it felt that in the selection of the personnel the functional element should be given more attention.

In the committee's opinion, the policy-making corporation is in every way better than the functional board. Here the Rao Committee has radically differed from the Estimates Committee. Also it does not accept the Estimates Committee's recommendation that the functions of initiating and making plans for a project should vest in the Central Water and Power Commission. The Planning Commission,

it might be mentioned, would prefer to entrust it to State Governments which may take assistance as required from the Central Water and Power Commission.

The committee holds that the Estimates Committee's proposal would make the Central Water and Power Commission very unwieldy and that it is doubtful whether the economy in planning and designing envisaged by the Estimates Committee would be realized in practice. "We suggest that freedom of corporations to choose their own consultants should, remain unhampered", says the committee.

/II. EQUIPMENT AND PROGRAMME - 7 -

II. EQUIPMENT AND PROGRAMME OF HYDRAULIC LABORATORIES

In the Flood Control Journal for September 1953 (ST/ECAFE/SER.C/16), information was given about the equipment and programme of the different hydraulic laboratories in the ECAFE region as well as in Australia and New Zealand. Further information has since been received from the Hydraulic research Station Krishnarajasagar (India) the Hydraulic research Laboratory, Dacca, East Bengal and the Hydro-Dynamic research Station, Hyderabad, Sind (Pakistan); it is given below.

INDIA

Hydraulic Research Station, Krishnarajasagar, Mysore

4. Additions to essential equipment available for experiments during

the past year.

A. Experimental flumes

20 All fixed, glass 2, masonry 18

B. Measurement of water level

6 Hook gauges

C. Velocity measurement

1 Pitot tube

2 Current metres

D. Discharge measurement (0.6 m3/sec) 4 Cipolletti weirs 20 cu ft/sec (1.5 m3/sec) 1 " " 50 cu ft/sec (0.6 m3/sec) 1 " " 20 cu ft/sec (0.06-0.15 m3/sec 4 " " 2-5 cu ft/sec (0.75 m3/sec) 1 90°V - notch 2.5 cu ft/sec m3) 1 Tank 700 cu ft (21

/F. Silt - 8 -

F. Silt

1 Soil auger

H. Other important equipment

2 20 hp pumping sets

5. Programme of work

New projects Applied problems for the design and study of spillways and protective works of new projects taken up.

6. Publications

(1) Annual Research Publication for 1952, by the Research Station, Krishnarajasagar

(2) Volute siphons, by V. Ganesh Iyer, Director

(3) "Dimensional Analysis as a Tool in Hydraulic Model Studies", by D. Doddiah, Assistant Director.

(4) "A Short Note on Surkhi Mortar", by D. Doddiah, Assistant Director

(5) "Lining for Irrigation Canals", by D. Doddiah, Assistant Director.

PAKISTAN

Hydraulic Research Laboratory, P.O. Tejgaon, Dacca, East Bengal

5. Programme of work

Continuing project

A. Model study of spillway of Karnaphuli dam

(1) Practical model study. Scale 1 : 90

(2) To determine the flow pattern and river bed scour for various discharges; lay-out of exit channel and guidewall.

(3) Results not yet available /(4) Started May 1952. - 9 -

(4) Started May 1952. To be completed December 1953.

(5) To be published in the annual Report of the Hydraulic Research Laboratory, Irrigation Directorate, Government of East Bengal, P.O. Tejgaon, Dacca. (English).

New projects

B. Model study of diversion channel of Karnaphuli dam (1) Practical model study. Scale 1 : 90.

(2) To determine the afflux at the upstream for passing the flood discharge through the diversion channel and to determine the effectiveness of the protective apron for prevention of erosion at the downstream end of the diversion channel.

(3) Results not yet available.

(4) Started March 1953. To be completed December 1953.

(5) To be published in the Annual Report of the Hydraulic Research Laboratory, Irrigation Directorate, Government of East Bengal, P.O. Tejgaon, Dacca. (English).

C. Model experiments for the prevention of erosion at Sirajgonj by the

river Jamuna

(1) Practical model study. Scale H - 1 : 200; V - 1 : 50

(2) To determine the position of spur for the prevention of erosion.

(3) Results not yet available.

(4) Started December 1952. To be completed September 1953»

(5) To be published in the Annual Report of Hydraulic Research Laboratory, Irrigation Directorate, Government of East Bengal, P.O. Tejgaon, Dacca. (English).

/Hydro-Dynamic Research - 10 -

Hydro-dynamic Research Station, Hyderabad (Sind)

1. Address - Experimental and Research Sub-Division, 10, Amil Colony, Hirabadm, Hyderabad (Sind).

2. Director- F.C. D'Abreo, Executive Engineer Technical staff 6

3. Available space and discharge Outdoor 20,000 sq ft Q-12-15 cu ft/sec H-3 ft gravity (1,850 m2) (0.36-0.45 m3/sec)

4 cu ft/sec pumping (0.12 m3/sec)

4. Essential equipment

B. Water level measurement

9 Point gauges

14 Hook gauges

C. Velocity measurement

2 Pitot tubes 1 Benzyl velocity tube 1 Baby velocity meter

D. Discharge measurement

3 Sharp-crested weirs

E. Silt

2 Bed silt samplers for small quantities 2 Binckley suspended silt samplers capacity 1,000 cm3 6 Measuring cylinders sedimentation method capacity 0.02 mm to 0.075 mm 1 Set of sieves 0.075 mm to 0.635 mm

/5. Present programme - 11 -

5. Present programme of work

A. Development of power from lowfalls by evolving efficient type of water wheel

(1) Research Project. Scales H - and V - 1:3.

(2) Programme of work not given.

(3) Results obtained, nil.

(4) Started 1952. To be completed 1954.

(5) No report issued.

B. Evolution of a module that requires less loss of head than Jamrao type modules

(1) liesearch project. Full scale

(2) Programme of work not given.

(3) Results obtained, nil.

(4) Started 1952. To be completed 1954.

(5) No report issued.

C. Mondar and Mahotta Regulators on Rice Canal

(1) Model study scale, Scales H - and V - 1:3.

(2) Programme of work not given.

(3) Results obtained, nil.

(4) Started 1953. To be completed 1954.

(5) No report issued.

D. Scour below Naulakhi Cross - Regulator on Rohri Canal

(1) Model study. Scales H - and V - 1:3.

(2) Reduction of scour.

(3) Results obtained, nil.

(4) Started 1953- To be completed 1954.

(5) No report issued. /III. ESTIMATING MAXIMUM - 12 -

III. ESTIMATING MAXIMUM FLOOD 1/

For the design of Pine Tier Dam in Australia, a new approach to the problem of estimating maximum flood was sought, in the absence of records for a sufficient length of time.1/

It was found that when unusual flood discharges in Tasmanian rivers were

plotted, Creager's curve with C = 30 formed a limiting curve.2/ To estimate maximum possible floods in the future the flood indicated by the C = 30 curve was taken and an allowance made for possible greater floods in the future. The catchment area above the dam is about 300 sq mi (768.3 km 2 ), giving a maximum possible flood on this basis of 100,000 cu ft/sec.

An attempt was made to check the estimate by using synthetic unit hydrograph methods. In the first instance maximum possible rainfall figures for a thunderstorm type of storm were assumed, based on some Victorian figures available, and the maximum possible flood indicated was 100,000 cu ft/sec (3,000 m3/sec). Later, estimates of the maximum possible rainfall from a thunderstorm in Tasmania were published by J. Walpole of the Commonwealth Weather Bureau and the maximum possible flood then indicated was 70,000 cu ft/sec (2,100 m3/sec).

However the constants used in the synthetic unit hydrograph calculations were assumed without any check being possible. Furthermore, it is possible that the flood as indicated by the thunderstorm could be exceeded. It was therefore decided to retain the original estimate of 100,000 cu ft/sec (3,000 m3/sec).

The scores of lagoons and lakes in the upper reaches of the catchment undoubtedly have a great effect in reducing flood peaks. The largest flood known in the Nive at the dam site is 21,000 cu ft/sec (630 m3/sec) in June 1952.

/IV. progress in rainmaking

1/ Abstracted from Whitham, L.S., "Pine Tier Dam Design", Commonwealth Engineer, 1 August 1953, P. 5. 2/ Creager, Justin and Hinds: Engineering for Dams, Vol. I, p. 126 - 13 -

IV. PROGRESS IN RAINMAKING RESEARCH IN AUSTRALIA1/

Recent advances in meteorology have led for the first time to a fairly clear understanding of the physics of rain formation. This new knowledge has brought with it possibilities of stimulating rainfall artificially by imitating the processes that are now known to initiate natural precipitation.

The first claims to success in rainmaking experiments of this kind were made in the United States of America in 1946. They naturally aroused great

interest in Australia, which, with its important pastoral and agricultural industries and its large areas receiving low and uncertain rainfall, would stand to benefit enormously from any satisfactory method of making rain.

Research on this subject has been carried on actively since 1947 at the radio-physics laboratory of the Council of Scientific and Industrial Research Organization (Australia) by a team under the leadership of Dr. E.G. Bowen. Whilst

"making rain" is the long-term objective of the radiophysics programme, the latter includes research into all aspects of the physics of rain and clouds.

Much experimental and theoretical work is being carried out on the phenomena of natural rain formation, a clear knowledge of which must necessarily be the basis for developing rainmaking techniques. The behaviour of the various materials used in rainmaking has been studied by laboratory experiments; and finally, extensive field trials of methods of artificial rain formation have been conducted.

In all this work, the emphasis has, in general, been upon gaining an under­ standing of the processes taking place and assessing the merits of the various rainmaking techniques, rather than upon immediate attempts at rainmaking on a commercial scale.

/MECHANISM OF RAIN

1/ Abstracted from Labrum, N.R., "Progress by the Council of Scientific and Industrial Research on Rain making Research in Australia", Commonwealth Engineer, 1 May 1953, p.410. - 14 -

MECHANISM OF RAIN FORMATION

In temperate climates, most rain is probably produced by a process that takes place in the upper layers of the clouds, where the temperature is below the normal freezing point of water. Such clouds may consist entirely of super­ cooled droplets of liquid water; they will then as a rule be quite stable and will not release any precipitation.

If, however, ice crystals enter such a cloud, they will grow by sublimation of some of the water vapour in the surrounding air; the cloud droplets at the same time evaporate to maintain the water vapour pressure at its equilibrium value. The effect of ice crystals in the cloud is, therefore, to convert the minute super­ cooled droplets orginally present into a much smaller number of ice crystals, which finally grow large enough to fall, melt and become rain.

This hypothesis at once suggests that it should be possible to "trigger-off" precipitation from suitable clouds by producing ice crystals in them. Two methods of achieving this will now be discussed.

"DRY-ICE" RAINMAKING

One way of inducing ice crystals to form in a cloud is by cooling the cloud sufficiently for direct sublimation of ice from water vapour to take place. Laboratory experiments have shown that a pellet of "dry ice" (solid carbon dioxide, with a temperature of -78°C) can produce this effect provided that the cloud temperature is below about -1°C. Accordingly, dry ice has been widely used in attempts at rainmaking.

Extensive tests of this method were made by members of the radio-physics laboratory from 1947 to 1950. In a typical experiment, a selected cloud was "seeded" by dropping 50-100 lb of dry ice, broken up into small pellets into the cloud from an aircraft flying above it. The cloud was carefully observed both visually and by radar, before and after treatment; flights were made below cloud base to determine whether rain reached the ground and rain-gauge data and the impressions of residents in the locality were subsequently collected and taken into account.

/A success was - 15 -

A success was claimed if there was clear evidence of rain having fal1en

from the treated cloud soon after the dry ice was dropped, but not from other clouds within a 20 or 30 mi radius. On this basis, 12 out of 88 rainmaking flights in the Sydney area were successful.

Although this appears to be rather a low ratio, E.J. Smith has shown, by analysing the results and the meteorological conditions prevailing, that a much improved forecasting technique could be used for any future dry-ice rainmaking in the Sydney area, with an expectation of about one success for every two flights.

The effect of dry-ice treatment upon clouds is in many cases quite spectacular, owing to the turbulence set up by the heat liberated in the conversion of the liquid water into ice.

RAINMAKING WITH SILVIA IODIDE

An alternative method of inducing precipitation from super-cooled clouds is to produce in them nuclei upon which ice crystals can sublime at ordinary cloud temperatures. For this purpose much use has been made of minute crystals of silver iodide which are dispersed into the cloud in the form of a smoke by means of a suitable burner. The latter has usually been located on the ground, on the assumption that natural convection will suffice to carry the particles up to the

cloud layer.

This technique has been used extensively in America since 1948, and very impressive claims have been made for it. Examination of the data suggested, however, that many of these claims might be over-optimistic, largely because of unsound methods of analysing the results. It was, therefore, decided to carry

out careful tests of the method in Australia.

The Riverina district was selected as the site for this work, on account of its uniform topography and rainfall distribution. A silver iodide smoke

generator was set up at Hay, N.S.W., and was operated for three months (July-September 1951) on all days when suitable clouds were thought to be present.

/The method of - 16 -

The method of assessing the results was based on the assumption that the smoke would drift downwind from Hay. All rain-gauge data within a 100 mi radius of the burner were collected and analysed to determine whether the rainfall in the downwind sector was higher than normal in relation to that in the rest of the area (rainfall records for previous years provided a basis of comparison).

Calculations showed a slightly positive result which, however, was not statistically significant - i.e. the random variations in rainfall were so great that a considerably longer series of tests would be needed to give a definite answer.

Before any more extensive trials of this kind are attempted, an investigation is being made of the way in which silver iodide smoke spreads through the atmosphere, and also of how long the particles remain effective as ice-forming nuclei.

Both questions, which have hitherto been neglected, are of considerable importance; it is known from laboratory tests that silver iodide does not promote ice-crystal formation at temperatures above about 15°C, which means that the smoke must as a rule reach an altitude of 10,000 to 15,000 ft in the cloud to produce any effect.

RAIN FROM NON-FREEZING CLOUDS

It has been shown by Bowen that rain may be produced from clouds that are warmer than freezing temperature, by a coalescence process - small drops from near the cloud-base are carried upwards by vertical air currents; they pick up cloud droplets until they grow large enough to fall again and, in some cases, reach the ground as rain.

The frequent occurrence of rain formed in this way in the Sydney area has been confirmed by direct observations. It appears highly probable that the process could be artificially stimulated by providing a supply of water drops of the correct size near the base of suitable clouds. This technique has not yet been fully exploited, but shows great promise.

/There are two - 17 -

There are two possible methods of carrying it out; the more obvious is simply to spray water from an aircraft. This has certain practical disadvantages, as compared with the alternative of dispersing particles of some hygroscopic substance, which then take up water from the moist air and produce drops of the appropriate size.

At present, finely ground sodium chloride (common salt) seems to be the

mostpromising material for this purpose,

CONCLUSIONS

From the foregoing account, it is fairly obvious that the science of rainmaking is still in its infancy, a few tentative conclusions can, however, be drawn at this stage.

Firstly, it is undoubtedly practicable to stimulate rainfall on a small sca e under suitable conditions, at least by the dry-ice method. These conditions, however, are fairly stringent, and include the presence of suitable clouds, so that rainmaking is not necessarily possible in any given locality.

Secondly, prospects of making wholesale climatic changes by any of these methods are remote, and the cost of any attempt at producing such large-scale effects would at present be prohibitive.

Thirdly, it seems that it might be feasible to influence appreciably the rainfall over a limited period and area; this would, for instance, be of tremendous value to Australian wheat-growers, who require adequate rain over a very short period in the year to ensure germination of their crop. The attainment of even such a limited objective would be of such great importance as to justify amply the effort which is now being spent on rainmaking and rain physics research.

/ V. ATOMIC PROBE 18 -

V. ATOMIC PROBE FOR SOIL MOISTURE MEASUREMENT1/

Use of an "atomic" probe and a recording Geiger counter for

measuring soil density and moisture is reported in Roads and Road Construction, February 1953, p. 54. The article states that the method is being used by the US Civil Aeronautics Administration in connexion with the design of airport run-ways. It is expected to prove valuable also in highway design and in agriculture.

The "atomic" measuring method is simple to use and the

equipment is relatively inexpensive. Basically it consists of a radioactive source and a detector, which are lowered into a 1" stainless steel tube driven into the ground.

The same electronic recorder is used for making measurements of both density and soil moisture. The probes for the two purposes are similar in appearance but different in their arrangement.

/ VI. REGIONAL PROJECTS

1/ Abstracted from an article in Commonwealth Engineer, vol.40, No.II, 1 June 1953, p. 456. - 19 -

VI. REGIONAL PROJECTS

HONG KONG

Proposed irrigation schemes in the New Territories

The Colony lies in a humid region and has an average annual rainfall of 84.76 in (215.3 cm), Unfortunately about two-thirds of the annual rainfall occurs in one third of the year, from May to August inclusive, and the minimum rainfall for the months of March, April, September and October is very low. The summer crop season extends from March to October.

A study of the occurrence of droughts and dry spells from 1884 to 1938 (55 years) shows that there were 51 absolute droughts, 1 partial drought and

34 dry spells during the period March-October. Only one of the 55 years was entirely free from droughts or dry spells and it had the maximum recorded rainfall of 119.7 in (304 cm). Only three years had no absolute drought. Moreover, there is no uniformity in the rainfall and it is continuously changing from year to year and from month to month. Rainless periods of a duration of one week or more during the crop-growing season are therefore frequent occurrences in this territory. Furthermore, as in most humid regions, the soil, generally speaking, is shallow and therefore capable of storing only a small depth of water for the future use of plants. When long periods occur between rains, crop growth is retarded or may result in a complete failure.

For example during 1952, which was generally considered a wet year, in many localities, over 30 per cent of the second rice crop failed to mature and the yield of another 30 per cent was below half the average. Failures of this nature are not uncommon in the New Territories.

Topographically, about 70 per cent of one total area is composed of steep mountain ranges without any large forest, and its geological formation is simple, granitic, and trappean with metamorphic rocks largely predominating. The soil in the valley plains is sandy loam seldom more than one foot deep. In general, the stream or river valleys are narrow and steep. The stream flows vary a great deal with the seasons. During intensive rainfall in the rainy season, the lower

/part of - 20 -

part of nearly every stream is flooded to a great extent, whilst in the dry season the stream flows are reduced to very small proportions. In fact some dry up altogether, and in others it is estimated that the minimum dry weather discharge is only about 200 gal/day per acre of catchment area.

In order to avoid losses due to decreased crop yield from occasional droughts, to ensure continuous and rapid growth of valuable truck and field crops, and to convert irrigable virgin land into productive land, a supplementary irrigation system is therefore necessary in this territory.

The existing condition of irrigation

According to investigations made by the Agricultural Department there are at present about 22,000 acres (8,800 ha or 65 per cent) of paddy and 12,000 acres (4,800 ha or 35 per cent) of dry cultivation in the New Territories. The

crop yield front the dry cultivation is entirely dependent on natural rainfall and if on an average one in every two crops is successful, it is fortunate. In paddy areas the local farmers usually get their irrigation water by diversion from a stream. But in most cases the dam is porous and the farm ditches are too small both in size and length for the area to be irrigated. They are full of weeds, on sandy loam soil and without proper gradients. Most of the, water is conveyed through one paddy field to another.

There appears to be no co-ordination between one system of irrigation and another, nor between any two sets of farm ditches in one small area, suggesting that there is little co-operation among the local farmers in planning their irrigation system. In this way fields bordering the stream usually get more water than they actually need, while those further away got nothing. Thus part of the available water is not utilized. In some localities such as Sha Po, Ngau Tam Mi and Ma Ku Lam, natural springs are to be found in the foothills, but none of them is developed and fully utilized. Instead, the springs are allowed to convert the surrounding; area into swamp or waste land.

Irrigation of a rice crop differs from irrigation of other crops in that complete submergence of the rice field to a depth of 4 or 8 in (10 or 20 cm) is necessary for the best production. The period of submergence begins

/with the - 21 -

with the planting of the crop and continues until about two weeks before harvest.

The growing season of the first crop is usually from the middle of April to the middle of July and the second crop from the middle of July to the end of October,

Estimate of water requirements

According to the climate and the character of the soil in this territory, the rice crop during the growing season is estimated to require an average of about 2.5 acre-feet per acre (7,709 m3/ha) of paddy field. That is the equivalent, of about 0.33 in (0.8 cm) of rain per day or 10 in (25.4cm) per month, During most of the growing season the average rainfall exceeds this figure, and there is no difficulty with water.

In most years, however, there is not this amount of rainfall in the April planting period, with the result that the early planting is largely dependent on irrigation water diverted from hillside streams.

Unfortunately the streams are almost at their lowest at this time of the year, with the result that the amount of paddy that can be irrigated is very limited. Thus much of the paddy cannot be flooded in time to produce two crops during the summer season, and therefore becomes ono-crop paddy. There is also the possibility of lack of rainfall towards the end of this season but this is less critical as streams are running fairly high as a result of summer rains. The problem is primarily, therefore, one of providing for the spring planting.

Available water resources

(a) Surface water

In the absence of proper irrigation channels, it is difficult to obtain accurate readings of the amount of water at present drawn by the paddy. Investigations were made however during the 1953 planting season to determine the amount of water available in the stream feeding the large area of the Kam Tin Plain. This is a very typical area with about 3,272 acres (1,309 ha) of cultivated

land, but the total flow of the streams was estimated to be not more than 1.5 cu ft/sec (0.05 m3/sec) and this would only be sufficient for 107 acres (43 ha).

In the absence of any large river it is obvious therefore that if an appreciable assistance is to be given at this period in a dry year the extra water required

/can only be - 22 -

can only be obtained from adjacent valleys, underground sources or storage reservoirs. As the water in adjacent valleys is normally just as much in demand, only underground water and storage reservoirs remain to be considered.

(b) Underground water

No thorough investigation has ever been made of the possibilities of underground supplies in the Colony. Owing to the general granitic nature of the rocks, however, extensive supplies are unlikely. Shallow wells in the low-lying areas are common, and these, together with a number of springs, could probably be further developed in small areas not easily reached by the main irrigation channels. The possibility of deep well supplies is at present being investigated. Plant suitable for trial bores to be made to depths of 2,000 ft (600 m) is

already on order. It is therefore recommended that any attempt at the development of underground water should await the result of these tests. As the plant on order can only locate water, it is suggested that provision be made from the irrigation funds for a deep well pump to test the capacity of the bores and, if successful, to provide for permanent lining and pumps.

(c) Storage reservoirs

In the absence of large rivers, the only reliable means of providing large quantities of water, when required, is by storage reservoirs. But the New Territories do not lend themselves readily to this method, and where there are obvious sites they are already either in use or earmarked for domestic water supply purposes. There are, however, a few possible sites in the vicinity of the large plains in the north and north-west of the Territories. Although such schemes would obviously be very expensive, if they can turn one-crop into two-crop

land they would very soon pay for themselves. For instance, in a normal year, the amount of stored water required per acre of paddy would be about 1 acre-foot (1,233.5 m3), i.e. 271,327 gal, or 271 million gallon per 1,000 acres. A reservoir to store this amount of water might well be built for HK$5 million. This would

produce additional crops worth HK$500 per acre per annum, i.e. HK$500,000 per annua, and thereby pay for itself in 10 years. These figures are very tentative, but they do indicate the desirability of investigating more fully one of the more promising sites for a dam.

/Summary of - 23 -

Summary of proposals

Proposals put forward, therefore, can be divided into three categories:

(a) The construction of a number of irrigation channels. They would be designed to make the fullest possible use of existing stream supplies, and include distribution channels and also repairs and overhauls to existing works as necessary. Table 1 gives details of 8 proposals under this head. At the present stage of the investigation, complete data cannot be provided but it should be- possible from the experience gained with these few schemes to determine the most economical development for the many other areas still awaiting attention. These works are all of a type which can be operated and maintained by the Villagers, under the directions of government engineers.

(b) The greater use of shallow wells and springs and the sinking of test borings. a few shallow wells could be sunk preferably on the sites of existing springs, and their output properly checked. Details are given on table 2. Deep well boring experiments will probably commence before the end of this year under the direction of the Waterworks Office of the Public Works Department. The plant on order however comprises only boring apparatus and it is, therefore, proposed that provision be made for a deep well pump for testing and, if this is successful, for permanent lining and pumping equipment at a later date. Enquiries are being made in regard to the costs of these items.

(c) The investigation of the possibility of extending the scheme by the erection of storage dams. The cost of the investigation is estimated at £10,000 but the results, if satisfactory, would be of far-reaching importance to the New Territories.

Tar Lam Chung Valley Scheme

By far the most important extension of the waterworks commenced during 1953was the Tar Lam Chung Valley Scheme, This is a new storage reservoir scheme

complete with ancillary works. -Investigations which began some years before the war were continued with a view to providing an additional storage reservoir of about 7,000 million gallons capacity in the Tar Lam Chung Valley, which is situated 16½ mi (27 km) from Kowloon along the Castle Peak Road. Consulting engineers had reported on the scheme in December 1940, but owing to difficulties in deciding

on the best site for the dam, a decision was not possible before the war. The site of the dam was not settled until 1948. By this time the cost of the scheme, Table 1

Proposed irrigation channels

Lin Fa Tei Locality Tan Hang Wong Chuk Dai Kong Po Ngau Tom Mei Ngau Tom Mei San Hui Ma Ku Lam Luk Keng Shui Lau Tin

Lumber of 1 2 3 4 5 5A 6 7 8 scheme

Irrigated area 300 163 238 391.5 360 40 213.88 (acres) 119 67

Catchment area 1,300 1,066 1,990 164 147 316 2,900 762 (acres) 645

Available All water All water All water water during used at used at used at 32,800 121,000 86,000 Little 152,400 129,000 dry season high levels high high (gal/day) levels levels -

24 Length of

main channel 5,500 3,225 5,975 3,000 3,845 4,543 2,230 8,324 5,000 - (feet)

Slope of channel 0.23 0.11 0.018 0.20 0.22 0.44 0.019 0.23 0.30 (%)

Size of rectangular channel 24 x 14 18 x 12 18 x 12 14 x 12 18 x 12 18 x 12 24 x 14 18 x 12 12 x 10 (inches - 2" Freeboard)

Maximum 2.12 capacity 5.80 2.59 1.01 2.44 1.49 0.80 3.50 1.86 (cu ft/sec) Cost of channel improvement 21,300 ( HK$ ) 16,835 8,400 6,100 11,500 5,900 3,100 10,278 18,400

Number of 1 - Dam to be 1 - Dam 1 - Dam to i 1 - New - New dam 1 - New dams repaired be re­ be re­ None j 1 - New dam 1 - New Dam - Dams to dan dam paired paired be re­ paired

Cost of dams 2,625 10,000 None 3,600 4,500 (HK$) 5,005 5,350 5,575 800

Total cost of scheme 21,840 11,025 16,100 11,500 9,500 7,600 15,628 23,975 22,100 (HK$)

Total : HK139,268$ -

Cost per acre 25 72.80 67.60 67.70 29.40 26.40 64.00 390.70 112.20 329.90 (hk$) -

Remarks Concrete Concrete Concrete Concrete Earth Earth Earth Concrete Lining of lining lining lining lining lining of channel is channel very- may be necessary reduced in this scheme - 26 -

Table 2

Underground water development - Shallow wells and springs

Irrigated area No. of Locality or cultivated Cost of development Cost per acre scheme area (acres) HK$ HK$

9 Sha Po 264 6,860 25.90

10 Mai Po 68 2,600 38.20

53.15 11 San Tin 200 10,630

Total 20,090 - 27 -

estimated at HK$21.6 million before the war, was now estimated at about HK$l00 million and financial difficulties held up progress.

With the ever increasing demand for water, however, it became imperative to obtain further supplies, and in the search for a way out of the impasse a proposal for development by stages was put forward. The suggestion was accepted and the consulting engineers asked to report again. Mr. H.J. Gourley, M.I.C.E., of Messrs. Binnie, Deacon & Gourley of Westminster, thereupon visited the Colony and as his report endorsed the suggestion, his firm was instructed to proceed immediately with detailed designs.

The scheme comprises a mass concrete dam 130 ft (39 m) high built thick enough to allow of subsequent raising to 180 ft (54 m). By keeping the top water level down 50 ft (15 m) below the ultimate level, the construction of four low subsidiary dams has been deferred. The storage capacity at this stage will be 1,150 million gallons, and the supply aqueduct is being designed to discharge 10 million gallons per day, except for the tunnels which are designed for the ultimate maximum draw-off of 40 million gallons per day. The top water level being only 150 ft (45 m) above sea level, a gravity supply to Kowloon and Hong Kong is not possible. A pumping station at Tsun Wan, about 7 mi (11 km) from Kowloon, will boost the delivery up to filters and up to a service reservoir situated high enough to give a gravity supply to the urban areas. Pumps and filters are to be installed for 10 million gallons per day.

INDIA

Lifting dam across river Tunga in Mysore State1/

The Tunga Anicut Project, one of the major capital irrigation works now under progress in Mysore State, is another milestone in the progressive development of irrigation, undertaken by the State during recent years. It is one of the river valley schemes included in the Five-Year Plan. /The river

1/ This paper has been specially prepared for ECAFE by L.C. Muniswamy Reddy and submitted through the Chief Engineer for Irrigation, Mysore. - 28 -

The river Tunga takes its origin in Gangamula, situated in the Western Ghats just about 18 mi from Sringeri, a well known place of historic importance and the seat of Goddess Sharadamba (Goddes of Learning). This river runs in the two districts of Chikkamagalur and Shimoga, for a distance of nearly 85 mi and joins the river Bhadra at Kudli, which is about 8 mi from Shimoga. Thereafter the river flows as Tungabhadra which ultimately joins the river Krishna at Karnool. The hilly forest-clad catchment of about 865 sq mi (2,241 km 2 ) in its upper reaches, with an annual rainfall varying from 35 to 350 in (89-890 m), yields a large unfailing supply of water in the river, which has not been, so far, used for development of either power or irrigation in its basin. As a matter of interest, it may be mentioned that while the flow at Niagara Falls ranges from a minimum of 220,000 cu ft/sec (6,230 m3/sec) to a maximum of 260,000 cu ft/sec (7,363 m3/sec) the corresponding figures for Tunga are 50 cu ft/sec (1.4 m3/sec) in the driest summer to 240,000 cu ft/sec (6,806 m3/sec) in a year of highest rainfall such as 1924.

Ever since 1873 it had been contemplated to construct a dam across the river at a place called Mudaba near the 20th mile on the Shimoga-Mangalore road, i.e. a site 12 mi (19.2 km) upstream of the present anicut site. The idea had been abandoned, as it involved the submersion of very rich betelnut gardens as well as rich wet lands of Thirthahalli taluk.1/

In recent years, the idea of constructing an anicut across the river Tunga at the present site near Sacrebyle in furlong 4/8 of the Shimoga-Mangalore road was pursued during 1942, mainly with a view to developing irrigation under the Grow More Food Scheme and thereby making the State self-sufficient in food production. The investigation for the project was soon taken up and it was completed during 1945. It was revealed that it would be a promising scheme with thefollowing merits:

(a) The source of water supply is unfailing with an annual yield of 150,000 to 200,000 million cubic feet (4,248 to 5,663 million m3);

(b) The lands commanded are fertile, situated in the taluks of Shimoga and Honnali, which suffer frequent droughts;

/(c) The scheme

1/ District. - 29 -

(c) The scheme assures supply of water in the first reaches of the channel in Shimoga taluk;

(d) Nearly 21,500 acres (8,600 ha) will come under the channel irrigation; this adds to the food production by 13,000 t;

(e) The submersion is mostly forest lands and the villages submerged are only five minor ones;

(f) The utilization of water from this river comes within the purview of the agreement with the neighbouring governments;

(g) The storage in the anicut affords facility for protected water supply to Shimoga town.

In consideration of the above facts, the project received administrative sanction during 1945. A committee known as the Tunga Anicut Project Committee was constituted immediately thereafter, with officers of the Public Works, Revenue, Health and Agricultural Departments as members, to draw up comprehensive proposals for crop-planning, health and other developmental measures to be adopted under the scheme and to fix water-rates and contribution to be paid by the landholders who would benefit by the scheme. This committee has since concluded its deliberations and submitted its final recommendations on which orders of the government have been issued. According to this, an irrigable area of nearly 5,000 acres (2,000 ha) around the villages and Shimoga town, corning under the

command of the channels, is reserved as dry belt, as an anti-malaria measure. But with the advent of DDT and other malaria preventive measures, it may be possible to extend irrigation even in these areas, which will then bring an additional area of 5,000 acres (2,000 ha). The channels are designed to serve this additional extension.

Details of the project

The site selected for the construction of the anicut is at Sacrebyle (in furlong 4/8 of the Shimoga-Mangalore road) just 7.5 mi (12 km) from

Shimoga (see figure 1). The catchment of the river at the site is 865 sq mi (2,241 km 2 ). From the gauge records of the river maintained since 1936, it is

seen that an average annual flow of 200,000 million cu ft (5,663 million m)3

can be expected at the site and it is proposed to utilize 7,500 million cu ft (212 million m3) out of it, for irrigating 21,500 acres (8,600 ha).

/Head works - 30 - FIGURE 1 Bombay- INDEX PLAN OF Province

TUNNGA ANICUT PROJECT IN MYSORE

Honnali

Govinkovi Anjanapur Nyamati

Sowlanga Chelu

Kumsi Holalon

Ayanur

Kudli Holemonnur

(A) SHIMOGA

Bidar

Gajanur ' (B) BHADRAVATI. TUNGA ANICUT

Umblebyle

Mandagadde

(A) District Head Quarter (C) Anicut Head Work (B) Place of Mysore Iron & Steel Work - 31 -

Head works

The anicut, 1,200 ft (360 m) long, is constructed with surki-mortar masonry - 1,020 ft (306 m) of high coefficient weir with crest at R.L. 1916.25 and 180 ft (54 m) of two broad-crested weirs, i.e. 80 ft (24 m) length at R.L. 1921.50 and 100 ft (30 m) length at R.L. 1925.00 - in the river bed portion and on the left flank is an earthen bund 580 ft (179 m) long. In between the two is the portion of the scouring sluices, 105 ft (315 m) in length built of surki mortar masonry with 3 vents of 11 1/6 ft x 15 ft (3.4 x 4.5 m) with their sill at R.L. 1875.00, the average bed level of the river.

The anicut will have a maximum spillage of 13¾ ft (4 m) for a length of 1,020 ft (306 m) of high coefficient weir, 8½ ft (2.5 m) and 5 ft (1.5 m) respectively over the broad crested weirs. The height of the anicut above the deepest foundation is 59½ ft (17.9 m). The broad crested weirs are of the usual trapezoidal section. The special feature of the spillway section of the high coefficient weir, the length of which is 1,020 ft (306 m), is that this particular profile (figure 2) is the first of its kind to be adopted in India. The design was finalized after a series of model experiments conducted in the Hydraulic

Research Station at Krishnarajasagar. The bottom width of the weir section is 51 ft 2 in (15.35 m) from end to end. The front face is vertical for a height of 24 ft 4 in (7.3 m) from the average bed of river, and then takes a gentle parabolic curve up to the top crest. From the crest towards the downstream is another parabolic section for a depth of 16.16 ft (4.85 m) measured vertically from the crest, from which point, a slope of ¾ : 1 is continued for a vertical distance of 11.59 ft (3.48 m). Beyond this, comes the upturned bucket with a circular arc of 10 ft (3 m) radius. This is a sector of 91°-6' . The upturned bucket is finished with a toe-wall of 4 ft (1.2 m) width at top with a gentle curve

as shown in the cross-section of the weir enclosed. The object of the upturned bucket is to dissipate the energy of the mass of water flowing over the crest. The direction of flow is actually turned upwards and shot into the air wherein the energy gets dissipated rendering the foundation of the anicut safe.

/Scouring sluices - 3 2 -

feet

feet

nage i 901-1020 Cha 0-900

(2) (1) X2 = 4. X2 542Y =7.944Y

2 WEIR X

thick 2'

Axis

-

pron A

A/Parabola B/Parabola Ç/Y 1930.00

- HIGH-COEFFICIENT

Pinstone WEIR

OF

or

F.M.L. Crest-1916.25, ikat j PROFILE Su feet)

BROAD-CRESTED

=20 OF

” 1

SECTION (Scale 1930.00

.L. 1930.00

M.F -

MYSORE ”

9

IN

M.F.L. Crest-1916.25

\ PROJECT

R.C.C.ARCH thick Crest

NICUT Springing

A A h Anicut c SLUICES Ar

TUNG

Introdus of 2.

"Groove f o rG ates SCOURING PLAN Horizontal Arch Figure OF

SECTION - 35 -

Scouring sluices

Three scouring sluices of section 11 1/6 ft x 15 ft (3.35 m x 4.5 m)

are provided on the left side of the anicut masonry, with horizontal arches on top. Steel shutters manufactured by the Mysore Iron and Steel Works are provided

for operation of these sluices.

Earthen embankment

The height of earthen bund above the foundation level will be 43 ft (12.9 m) and the top width is 18 ft (5.4 m) with side slopes of 1½ : 1 upstream

revetted with size stone work and 2 : 1 downstream, turfed over. There is a berm downstream at R.L. 1916.25 to a width of 15 ft (4.5 m)

Deviation of the Shimoga- Mangalore road

As the anicut submerges a length of nearly 4 mi (6.4 km) in four low-lying

bits of the Shimoga-Mangalore State Fund Road, the road is deviated in four loops involving a total distance of 7¼ mi (11.6 km) with five major masonry

bridges, 23 culverts and good metalled surface.

Head sluices

The surki-mortar masonry sluices on left flank of the anicut have 5 vents of 10 ft x 6 ft (3 m x 1.8 m) with sills at R.L. 1910.00. The sluices on the right flank have 3 vents of 10 ft x 4 ft (3 m x 1.2 m) with their sill at 1912.00.

The left head sluices provide a drive-way on top to a rest-house to be situated on the adjacent hill-top.

Irrigation channels

Two channels from both the extremities on the right and left banks are excavated. The Left Bank Channel which takes off at R.L. 1910.00 with a maximum discharge of 550 cu ft/sec (15.6 m3/sec), runs for a length of 63 mi (100.8 km)

in the taluks of Shimoga and Honnali, commanding an irrigable area of 16,500 acres (6,600 ha), before it drops to a stream (Marihalla) near Honnali, which joins the

river Tungabhadra. The special feature of this channel is that it runs in a tunnel for a distance of 1,565 ft (469.5 m) near Shimoga. The velocity of flow in the tunnel is 8.2 ft/sec (2.46 m/sec), the bed-fall being 9*38 ft/mi (1.76 m/km).

/The deep - 34 -

The deep approach and draft cuts of the tunnel area 1½ and 2½ furlongs long respectively with a velocity of 3.5 ft/sec (1.05 m/sec).

The Right Bank Channel which takes off at R.L. 1912.00 with a discharge of 130 cu ft/sec (3.68 m3/sec), runs for a length of 32 mi (51.2 km) in Shimoga taluk, commanding an extent of 5,000 acres (2,000 ha) before it drops into the

river Bhadra near Kudli.

A total of 63 villages are benefited by the waters of Left Bank Channel

in taluks of Shimoga and Honnali and 20 villages by the Right Bank Channel in Shimoga taluk. The crops proposed for irrigation from the channels are 5,000 acres

(2,000 ha) of sugar-cane at a duty of 70 acres per cu ft/sec (1,000 ha per m3/sec) and 16,500 acres (6,600 ha) of paddy at a duty of 45 acres per cu ft/sec (643 ha per m3/sec).

Water rate and contribution

The rates in respect of the lands benefited are at present fixed as follows:

Water rate: Rs 6/- per acre of dry land to be converted into wet and Rs 4/- per acre of existing wet and garden lands.

Contribution: Rs 45/- per acre of dry land to be converted into wet and Rs 30/- per acre of existing wet and garden'lands proposed to be included in irrigation under the anicut.

The capital cost of the scheme amounts to Rs 23 million. As per the ”Go Slow" programme the first stage comprises the completion of head works in all respects, and the excavating of 20 mi (32 km) of Left Bank Channel and 4 mi (6.4 km) of Right Bank Channel, at a cost of Rs 15 million. Under the works of first stage, an extent of 5,000 acres (2,000 ha) will be benefited.

The second stage works, consisting of the remaining 43 mi of Left Bank Channel and 28 mi of Right Bank Channel, will cost Rs 8 million and after their completion the remaining 16,500 acres (6,600 ha) of land will be benefited.

/Progress on - 35 -

Progress on works up to the end of July 1953

Although the construction work of the project actually started in June 1946, the preliminary work such as clearing of the jungle, formation of colonies, construction of temporary quarters to house the labourers, staff, officers, stores and hospital and formation of approach roads to the work-spot and stone quarries, erection of mortar mills, procurement of necessary tools and plant etc., covered a period of nearly three years. During this period, excavation for foundation of the anicut and of the channels on both banks progressed simultaneously. It was only after 1950 that the real work on the project was taken up.

During the two and a half years ending July 1953, sufficient budget grants were allotted by the State and substantial progress has been secured on the first stage works.

The full length of high-coefficient and broad-crested weirs have been completed. For the first time, there was discharge over the entire length of completed anicut. A maximum spillage of 8.15 ft (2.45 m) over the high-coefficient weir, discharging 110,280 cu ft/sec (3,123 m3/sec), was observed during the floods of this year. The anicut has stood the discharge very satisfactorily. The action of upturned bucket has been observed for spillages of 1¾ ft (0.5 m) and more only.

The scouring sluices have been almost completed and the construction of a view-stand and parapet remains to be done. The steel gates for the scouring sluices, supplied by the Mysore Iron and Steel Works, Bhadravati, have been fixed up. The winches are being erected for operation of the shutters.

The earthen embankment has reached R.L. 1935.00 and is being raised to R.L. 1936.00 the top level. The side stone revetment has gone above the maximum flood level of R.L. 1930.00. The downstream slopes have been formed and turfing has been completed.

/The masonry - 56 -

The masonry head sluices on both the flanks have almost been completed,

except for providing parapets etc. The crab-winches with steel shutters have been erected. The steel shutters for sluices have been manufactured and supplied

by Messrs. Duncan, Stratten & Co., Bombay.

The works for deviating the Shimoga-Mangalore road, including cross­ drainage works, have been completed and the road has been put into service.

Twenty miles of Left Bank Channel from the Left Head Sluices and 6 mi

of Right Bank Channel from the Righ Head Sluices have been excavated and cross­ drainage works are nearing completion in those lengths. The tunnel near Shimoga along the Left Bank Channel, for a length of 1,565 running feet has been

completed, inclusive of lining.

An extent of 4,000 acres (1,600 ha), within the first 14 mi (22.4 km) of left Bank Channel and 6 mi (9.6 km) of Right Bank Channel, can be supplied with water for irrigation at present. If the railway bridge across the Birur Talaguppa Section is completed, water can be supplied for another 1,000 acres (400 ha) from another 6 mi (9.6 km) of Left Bank Channel.

Now that the works contemplated for the first stage are almost complete in all respects, the second stage works, namely the extension of both channels for the remaining lengths in accordance with the project scheme, are being pursued vigorously and after completion of this stage, which may take about two years, the total extent of 21,500 acres of irrigation can be realized. The completion of the second stage works would be a permanent measure of relief against famine in the drought-stricken area of Honnali taluk.

There is a Standing Technical Advisory Committee consisting of expert engineers of the State who are visiting the works quite often and giving valuable advice and suggestions on all important matters connected with the scheme.

The project finds prominent place under major irrigation works in the Five-Year Plan approved by the Government of India.

/ WalayarThe - 37 -

The Walayar Irrigation Project1/

The Walayer Irrigation Project on the Coimbatore-Malabar border costing about Rs.10 million, and the Manglam Irrigation Scheme on the

Cochin-Malabar border, costing Rs 4.6 million, are the second group of mid-term irrigation works in the plan for irrigation development sanctioned by the Madras Government to irrigate an ultimate area of over 10,000 acres (4,000 ha) of first and second and in some cases third crops. Both these projects are small as compared with other irrigation schemes in India. They are mainly intended to step-up food production in the deficit district of Malabar.

Although efforts have been made since 1910 to provide the Malabar district with irrigation schemes to supplement rains, certain legal and engineering difficulties stood in the way of an early start.

But the acute food shortage, particularly in the Madras State and the Malabar district, resulting from a world scarcity of foodstuffs, made the government and the people change their angle of vision and take all possible steps to grow more food at any cost.

While one million cubic feet of water would irrigate about 5 acres (2 ha) of land in other parts of the State, the same water could profitably be made to irrigate about 15 acres (6 ha) in the Malabar district in an average year. But the difficulties mentioned above made the cost per million cubic feet of storage higher in Malabar than in other places.

The Walayar Project comprises the construction of a dam to form a reservoir, the excavation of a distribution system, the acquisition of two private anicuts and the diversion of the Madras-Calicut trunk road for a length of about 10,000 ft (3,000 m) as it will be partly submerged (see figure 3). The Walayar Dam will be built across the Walayar stream on the Coimbatore - Malabar border about half a mile south of the present

/bridge over

1/Abstracted from an article by R. Dorai Rajan in The Indian and Eastern Engineer, May 1953, p.699. - 38 -

Rivers and Streams COIMBATORE

TALUK Water Spread Area

Roads

Railways Eliyal Parapatti

Arkutal Walayar ; Proposed Walayar Dam KADU KAMKUNNU R.S 574 ft. Earthern Dam 4866 ft. Capacity 520.4 cu.ft. P.R.L. 661.00 Kenjinode M.W.L. 666.00 Vadassheri Anicut Crest 504.95.

Kayundan Anicut Crest 403.75 Halleseri Anicut Crest 460.75 Proposed New Ayacut Palghat Left Main Canal Walayar

Koyilakkam Anicut 339.12 Pol Pull. Olassheri Vandithodu Anicut 307.29

COCHIN Scale : 0 12 3 4 Miles TERRITORY

Figure 3 WALAYAR RESERVOIR SCHEME - KEY MPA - 39 -

bridge over the stream on the Madras - Calicut trunk road. The catchment drained by the stream at the dam site is 41.07 sq mi (106.41 km 2 ) lying both

in the Coimbatore and Malabar districts and the capacity of the reservoir

impounded by the dam will in the first instance, be 500 million cu ft (15 million m3) with an ultimate capacity of 700 million cu ft (21 million m3) when the shutters to bo installed over the spillway have been commissioned.

The modern trend in dam design in Madras State more or less favours the composite type following the model evolved for the Lower Bhavani project at the Irrigation Research Station, Poondi, with a central masonry spillway and earthen flanks. This is being adopted for several other irrigation projects as it is considered cheaper than all-concrete dams like the Mettur Dam. The Walayar Pam is also a composite structure with a central masonry spillway and earthen flanks. Its total (length) is 5,240 ft, (1,572 m) with an overflow portion 374 ft (112,2 m) long in masonry with two earthen flanks on either side. The left flank will be 3,005 ft (901.5 m) long and the one on the right 1,861 ft (558.3 m). The masonry spillway is of solid gravity type 85 ft (25.5 m) above river bed with a maximum water level at 75 ft (22.5 m), The area of the waterspread will be 609 acres (250 ha).

The spillway will be 354 ft (106.2 m) between abutments with wingwall upstream and downstream with crest and downstream face curved so as to conform to the flow of the water. The effective waterway excluding 9 piers, 6 ft (1.8 m) thick will be 300 ft (90 m). A lip has been added upstream in continuation of the upstream profile of the flow to give a higher discharge coefficient. A bucket with a radius of 20 ft (6 m) has been provided downstream to deflect the overflow sheet of water to a horizontal direction. The design of the dissipator is similar to the one at the Lower Bhavani Dam with longitudinal blocks and tee-heads. The stilling basin is 5 ft (1.5 m) deep and 10 ft (3 m) long with a simple vertical sill at the end and a single row of tee-blocks in the basin. The overflow section will be built of rubble masonry in cement mortar.

/to guard - 40 -

To guard against temperature cracks, construction joints are provided at 66 ft (19.8 m) intervals along the length of the masonry dam.

The joints will run through from upstream to downstream face of the darn and will consist of alternate recesses and projections to retard creep of water. To seal these joints, a U-shaped flexible copper strip will be embedded in the block of the masonry. In front of the copper strip, there will be a diamond shaped reinforced concrete stanchion post standing vertically on a non-porous sliding base and coated over the vertical face with marine flue. Water pressure will press the concrete column back against the front and behind it and seal it.

The profile of the earth darn in general will conform to the latest design adopted for the Lower Bhavani Project. This will consist of a central core of impermeable earth material, an upstream portion of semi-pervious material and a downstream portion of semi-pervious material consisting of more porous material available at site. The top width of the earth dam will be 24 ft (7.2 m) including parapets.

Provision is made for a future increase in the storage by installing ten 5 ft x 30 ft (1.5 m x 9 m) shutters over the spillway, thereby increasing the reservoir level from 661 ft (198.3 m) above sea. level to 666 ft (199.8 m) mean sea level. This will add another 300 million cu ft (8.5 million m 3 ) to the storage, making the total reservoir capacity 700 million cu ft (19.6 million m3 ), The area irrigated will proportionately be increased by 1,500 acres (600 ha).

Water from the dan will be let down the stream immediately below through two low-level sluices 4 ft x 5 ft (1.2 m x 1.5 m) and one high level sluice of the same dimensions. The sill of the low level sluices will be 9 ft (2.7 m) above the bod of the stream while the only high level sluice will be 16 ft (4.8 m) above the low level sluices. The low level sluices will bp designed to discharge 224 cu ft/sec (6.72 m3/sec) against 170 cu ft/sec

(5.1 m3 /sec) required for irrigation. The water thus let down the stream will be picked up 2 mi below the dan at two anicuts and supplied through a main canal and distribuatries to 5,680 acres (2,272 ha). Another1 1,000 acres

/(400 ha) on - 41 -

(400 ha) on the low-lying area will bo benefitted by the reservoir as well as from spring supplies for a third crop.

As 4,300 ft (1,290 m) of the present Madras Calicut concrete trunk road will be submerged, it will be re-aligned along the Southern Railway from Madras to Calicut for a distance of 10,000 ft (3,000 m) and carried over a new parallel bridge 400 ft (120 m) downstream of the present rail bridge joining the trunk road a furlong below the Walayar Railway Station. The maximum depth of submersion on the road will be 24 ft (7.2 m)

The Mangalam Project1/

The Mangalam Project consists of a reservoir, a pick up anicut and a distribution system to serve 3,280 acres (1,312 ha) in the Palghat taluk.

The dam will be 2,760 ft (828 m) long and will consist of three portions: a main masonry section of 150 ft (45 m) at the river crossing with flanking non-overflow section in continuation of the spillway for 285 ft (85.5 m) on the left and 165 ft (49.5 m) on the right, making up a total of 600 ft (180 m) of masonry dam; and earth connections in continuation of the non-overflow section for a length of 1,360 ft (408 m) at the left flank saddle and 410 ft (123 m) at the right saddle. The masonry dam is of the gravity type 60 ft (18 m) above the deepest bed of the river and 70 ft (21 m) above the deepest foundations. The reservoir will be limited to 250 million cu ft (7.5 million m3 ) capacity at the first stage and will be enlarged at a later date to 300 million cu ft (9 million m 3 ) by installing 5 ft (1.5 m) shutters over the spillway with discharge of 4,890 cu ft/scc (146.7 m3/sec).

The spillway is of the overflow type as in the case of the

Walayar Dam with crest downstream face curved so as to conform to the flow of the water. The clear waterway provided is 120 ft (30 m) excluding 3 piers each 6 ft (1.8 m) thick. The full length of the overflow section therefore from abutment to abutment is 138 ft (41.4 m). A bucket of 20 ft (6 m) radius will be provided downstream to deflect the overflow sheet of water to a horizontal direction. The stilling basin is 5 ft (1.5 m) deep and 10 ft

1/Ibid. /(3 m) long - 42 -

(3 m) long as at Walayar. The vertical blocks parallel to the sill are 6 ft x 3 ft (1.8 m x 0.9 m), 6 ft (1.8 m) apart and buttressed into end-sill by longitudinal blocks 3 ft x 3 ft x 7 ft (0.9 m x 0.9 m x 2.1 m).

The low and high sluices will be 5 ft x 4 ft (o.9 m x 1.2 m).

A bridge 6 ft (1.8 m) wide between parapets will be provided over the spillway to facilitate easy inspection of the dam. The top of the earth dam will be 24 ft (7.2 m) wide in some portion and reduced to a minimum of 12 ft (3.6 m) at flanks. The upstream slope will be 2½ to 1 and downstream slope 2 to 1. The pick-up dam, 3 mi (4.8 km) down the reservoir is 136 ft (40.8 m) long and 14.5 ft (4.35 m) high, of solid masonry and 5 ft (1.5 m) on crest with shutters ten spans of 10 ft (3 m) each. The head sluices will be located in the left margin above diversion work designed to draw 66 cu ft/sec (1.98 m3/sec). The main canal will be about 13 mi (20.8 km) long.

The Mayurakshi Project1/

The biggest of West Bengal's irrigation scheme, the Rs 15 million Mayurakshi Project, is perhaps the only river valley undertaking in India which has started providing irrigation in the very first year of construction of the reservoir. For sheer natural beauty, the dam site at Massanjore in the heart of the picturesque countryside of the Santhalas in Bihar has few equals. A ring of green hills studded with Santhal villages just above the valley provides a lovely background to the vast basin that will be turned into a lake. Noted for their wild-life, the tracks enclosing the lake are expected to serve as a

National Park.

The dam seeks to connect two hills where the Mayurekshi flows through a narrow valley. This rivulet, which originates from the up-lands of Santhal Pargunas, eventually carries an annual flow of water adequate to provide irrigation for the major part of Birbhum district in Bengal. A

Although the dam and the reservoir arc situated in Bihar, it is largely a West Bengal venture undertaken in co-operation with the Bihar Government. ______/The scheme 1/Abstracted from an article in Hindustan Times, 18 June 1953 - 43 -

The scheme provides for storage of water in the Massanjore Dara which will be led from the reservoir down the river over a distance of over 20 mi (32 km) to where a barrage has been constructed along with the head works of the canal system.

The barrage is located at Tilpara, 2 mi (3.2 km) from Suri, the district headquarters of Birbhum, and has been completed a year ahead of schedule. It feeds two main canals with reservoir capacity of 3,500 cu ft/sec (99 m3 /sec) and a length of 73 mi (116.8 km) each. The total length of distributaries is 1,000 mi (1,600 km).

The project will irrigate 600,000 acres (240,000 ha) in the autumn and 120,000 acres (48,000 ha) during the winter in the district of Birbhum Murshidabad and Burdwan in West Bengal and 30,000 acres (12,000 ha) in the autumn in Santhal Parganas in Bihar.

Although the new area that will be brought under cultivation is limited to 20,000 areas (8,000 ha), the supply of water to over 750,000 acres (300,000 ha) is expected to increase the yield of paddy to the extent of

300,000 t a year valued at Rs 65 million and winter by crops 60,000 t valued at Rs 15 million.

The crop-cutting experiment in the area of some 80,000 acres (32,000 ha) which was irrigated from the barrage during the autumn of 1951 has confirmed the estimated increase of half a ton per acre. It will thus be possible to recover the entire produce in two years.

Giant machines like crushers and draglines are conspicuous by their absence. The 1 million cu ft masonry and cement arc expected to be piled up by human labour to construct the 150 ft (46 m) high dam over a length of 2,200 ft (670 m). There will be 21 spillways each of 30 ft (9 m) span. There will be two sets of undersluices on the left bank. One set of three sluices will be located at a higher elevation, the other set will be at lower level. Power is sought to be produced to an extent of 2,000 kW.

/The construction - 44 -

The construction is already well advanced, the low-level undcrsluices gate frames were almost satisfactory. A major part of the lining construction will be completed during 1953-1954 when the construction of the power house will also he taken up. A gap is left in the centre of the dam to let the flood waters flow through. The filling up of the gap and fitting up of the spillway gates, including bridges, will he completed by 1954-1955.

A roadway on the top of the dam will bridge the spillway opening. It will provide an easy communication to the right bank. A garden with a number of fountains on the left flank downstream of the dam will add to the beauty of the area. A metalled road is under construction alongside the hills that skirt the lake on the left side, connecting the dam site with the town of Dumra. It will cut across the proposed National Park.

The lake will hold 500,000 acre-feet (617 million m3 ) of water

and cover an area of 55,000 acres (22,000 ha).

The Chalakudy River Development1/

The Chalakudy river, which drains the western slopes of the Anamalai (elephant) hill, passes through the former Cochin State and bids

fair to become one of the best utility rivers in India. In its upper reaches this river traverses thick forests intersected by narrow gorges containing falls and rapids which readily lend themselves to power development. It is estimated that the Chalakudy and its chief tributary, the Sholai Ar, have a potential for power development of 350,000 kW. Figure 4 is a map of the river.

The first stage of the Poringalkuthu site on the left bank of the

Chalakudy river is now under construction; initially 24,000 kW of capacity will be installed but ultimately 48,000 kW will be developed. The second stage, on the right bank of the river, would include the construction of a dam known as the Upper Dam, 3 mi above the present Poringalkuthu Dam and

just below the confluence of the Karapara and Sholai Ar, for a storage of 21,000 million cu ft (630 million m3). This reservoir will be capable of 1/Abstracted from an article by R. Dorai Rajan /regulating the in Water Power, June 1953, p.213. - 45 -

Karapara River Orukkuumban Kutty

SholaiAr.

‘'X^-vr

Upper Dam Site A/ u d o Th Thodu Right Bank

i Power House B/ Lower h 150,000 kW. C/ Dam Site Charpa

Vazhachaalkuthu E/ A/ Falls 190 ft. Intake Works Kanhankuz

Chalakudy River Poringalkuthu Left- Minari Thodu Bank Power House. Installed Capacity 24,000 kW.(1st State) Kallana Adirapally Falls 0 1 1 2 Miles R.H. (Forest) 184 ft. 2

Figure 4 A key plan showing the Poringalkuthu left- and right-bank schemes

A/ Tunnel C/ Pipeline

B/ Surge Tank D/ Anakayam Ar. E/ Chalakudy River. - 46 -

regulating the flow of the river to about 2,700 cu ft/sec (81 m3 /sec) for development of power. A diversion tunnel some 11,000 ft (3,300 m) long will carry the flow through the intervening hill to pipe lines 2,600 ft (780 m) long descending to the power house, 850 ft (225 m) below. Ths power station will contain five generating units capable of developing a total of 150,000 kW at 60 per cent load factor.

The catchment area of the river above the dam site is 349 sq mi (904 km2 ) and is drained by five streams, all tributaries of the Chalakudy.

The average annual rainfall over this area is 150 in and the average run-off was 87,000 million cu ft (2,610 million m3) during 1950-51 and 1951-52)

The Upper Dam, which is estimated to cost Rs 32 million will be 1,500 ft (450 m) long and will have a height of 230 ft (69 m) above river bed level. This construction will involve the laying of 19 million cu ft (0.57 million m3 ) of mass concrete and to mix and handle this material, two cable­ ways and a batching plant will be installed. It is estimated that this work will be completed in about 1,000 working days, or about four years, at the rate of 700 cu yd (536 m 3 ) a day. The project can thus be completed in five years allowing one year for preliminaries. A maximum flood discharge of 75,000 cu ft/sec (2,250 m3/sec) will be taken care of by radial crest gates

and two undersluices, costing Rs 2 million.

The maximum discharge through the 11,000 ft (3,300 m) tunnel, which is to cost Rs 7.2 million including the intake works, is 2,700 cu ft/sec (810 m3/sec), the velocity of flow being 8 ft/sec (2.4 m/sec). The area of

the finished section will be 337 sq ft (29.93 m2). It is expected that 95 per cent of the tunnel will be cut in solid rock and lined with 8 in of concrete.

Five penstocks, each 2,600 ft (780 m) long with a diameter of 7 ft (2.1 m) and designed for 530 cu ft/sec (15.9 m3/sec) discharge will feed

the five machines. The total weight of the penstocks will be 8,700 t, costing Rs 23.8 million, this including the control equipment.

/The surge - 47 -

The surge shaft will be 225 ft (67.5 m) high and will be cut in solid rock, the lowermost 55 ft having a diameter of 80 ft (24 m) and the remainder a diameter of 25 ft (7.5 m). The estimated cost is Rs 1.2 million.

The power house, which will be of reinforced concrete construction, will cost Rs 3 million including the travelling crane, which will be 350 ft (105 m) long and 85 ft (25.5 m) wide, and will accommodate five generators each developing 30,000 kW. The turbines, generators, switchgear and transformers will cost Rs 30 million.

At another site above this dam in the Sholai Ar, it is proposed to utilize a head of 1,000 ft (300 m) in conjunction with a storage capacity of 4,800 million cu ft (144 million m3) impounded by a 160 ft (48 m) high dam. A 5,000 ft (150 m) long tunnel will be necessary to bring the water to the power station which will be designed to generate 42,000 kW. The tailwater will join the

Anakayam Ar, also a tributary of the Chalakudy, about 14 mi above the Poringalkuthu site and join the main river above the Poringalkuthu Upper Dam about 5 mi upstream of the dam now under construction for the first stage of the Poringalkuthu left­ bank scheme.

Two other sites, downstream of Poringalkuthu, at the Vazhaehaalkuthu and Athirapally falls, where a total drop of 600 ft (180 m) is available, are also proposed for development and are estimated to be capable of accommodating

115,000 kW capacity.

Thus, there will finally be five generating stations on the Chalakudy river, utilizing the same water, while a total area of 99,000 acres (40,000 ha) will be irrigated. The Mudki-Golewala distributary system1/

More than 200,000 acres (80,000 ha) of arid land in Ferozepur

district in the Punjab and the contiguous Pepsu States will be irrigated by the Mudki-Golewala distributary system. The additional yield is estimated to be about 1,200,000 maunds (48,000 t) of food grains and 15,000 bales of

cotton per annum. The project will be completed by April 1954.

/The Mudki-Golewala 1/ Abstracted from an article in Hindustan Times, 21 May 1953. - 48 -

The Mudki-Golewala distributary system consists of four channels with an aggregate discharge of 539 cu ft/sec (15.3 m3/sec) and a total length of 153.5 mi (213.6 km). The system includes 104 masonry works with one siphon

7 head-regulators of the distributaries and minors with bridges, 24 falls, 2 railway bridges and 62 village road bridges. Out of a gross area of 217,283 acres (86,913 ha) which will be served by this system, nearly 195,548 acres (78,219 ha) are cultivable.

Till the completion of the Phakra Dam, the canals will work only in the rainy season when ample supply of water is available in the Sutlej river. After the completion of the dam, however, these channels will become perennial and will run throughout the year.

The total capital outlay - direct and indirect - has been estimated at about Rs 3 million. During the pre-Bhakra stage, these channels will function as non-perennial ones and the intensity of irrigation will be about 35 per cent after three years. This will yield a net annual revenue of Rs 180,000. In the post-Bhakra stage, these channels will be converted into perennial ones and the irrigation will develop to about 62 per cent, giving net receipts to the tunc of 28 per cent of the capital cost.

This scheme is a part of the Bhakra-Nangal Project in which provision has been made to increase the capacity of the Sirhind Canal at its head from 9,040 cu ft/sec (256 m3/sec) to 12,624 cu ft/sec (357.5 m3/sec). The increased

discharge will be utilized to extend irrigation facilities to new areas and to increase the intensity of irrigation in the old ones, To carry this extra discharge, it has become essential to remodel the head works at Rupar in order to raise the pond level, to enlarge the canal and its branches and to remodel the distributary systems. The headwork is already being converted into a

barrage with gated control in place of a long weir topped with dropping shutters. This work is well ahead of the programme and will be finished in

all respects before April 1954.

/Most of - 49 -

Most of the work of remodelling of the canal and its branches has been finished. Remodelling of the distributaries will, however, be taken in hand in the autumn and winter of 1953-54. In addition, this work of remodelling the headworks and about 2,012 mi (3,219.2 km) of channels without interrupting the normal irrigation operations, on extremely difficult and intricate task, has been quite taxing. The remodelling of the headworks and channels was started in October 1952. Nearly 200 million cu ft (5,665,400 m3) of earthwork and 2 million cu ft (56,634 m3) of concrete and masonry work has been done and about 2,000 t of steel have been consumed in the floor of the Rupar headworks. Nearly 20,000 labourers have been engaged on the job, besides the earth-moving equipment and other machinery.

The Lift Irrigation Scheme1/

A Rs 100 million scheme for the construction of five pump-canals in the eastern districts of Uttar Pradesh, besides other irrigation projects already included in the Rive-Year Plan, is under the consideration of the State Government. When completed, the canals will irrigate about 2,400,000 acres (960,000 ha) of additional land.

The scheme aims at providing sufficient irrigation facilities in paddy growing areas in the eastern districts where tube-wells arc considered in adequate to satisfy the need for enough water for paddy cultivation.

A survey has already been completed and it is found that the rivers, flowing generally from north to south in those areas, can provide enough water which can be lifted with the help of pumps to feed canals.

One canal will serve about 600,000 acres (240,000 ha) of land in

Décria and Gorakhpur districts by lifting water from the Gandak, while the second will be fed by the Ghagrain Tanda (Faizabad district) to irrigate about 1 million acres (404,690 ha) in Azamgash, Ghazipur and Jaunpur districts.

/Water will

1/ Abstracted from an article in Hindustan Times, 18 July 1953. - 50 -

Water will be supplied to about 500,000 acres (120,000 ha) of land in Azamgarh (east) and Ballia districts by the third canal which will be taken out from the Ghagra near Doright, while the fourth, which will be known as Sarju Canal, will irrigate 250,000 acres (100,000 ha) in Gonda and

Bahraich districts from the waters of the Sarju river.

The fifth project aims at lifting water from the Ganga and the Gandak to irrigate about 200,000 acres (80,000 ha) in Janupur district and in Banaras district between the Gomti-Ganga and Varun-Ganga doabs.1/

As electric power will be required to work the pumping system of these projects, the State Government is looking towards the Union Government which it is learnt, is actively considering taking up the Rs 300 million Bihand Dam Project in Mirzapur district. Until the Rihand Power Project is completed the State Government is considering the installation of three power stations, one each at Gorakhpur, Man (Azamgarh district) and Suheel, as an interim arrangement.

2/ The progress of the Damodar Valley Corporation2/

1. The Durgapur Barrage

The Durgapur Barrage is the last of the five projects that the

Damodar Valley Corporation is executing in the first phase of its programme. The others upstream are dams at Maithon on the Barakar, Pauchet Hill on the Damodar, Kmar on the Kmar river and Tilaiya on the Barakar. In addition, there is the Pokaro thermal power station. An 85 mi (136 km) navigation channel connecting Durgapur ccal fields with the Hooghly, 35 mi (56 km) above

Calcutta, is also included in the first phase. Of the eight dams suggested by experts, four - Aiyar, Bermo, Balpahari and Bokaro - have been included in the second phase of development.

The purpose of the Durgapur Barrage is to utilize the discharges from the dams upstream for irrigation. Of its extensive canal system, the main canal on the left bank will be the navigation channel. It also will drain many miles of channels in the low-lying areas of the valley, making them arable. 1/The area between two rivers /The total 2/Abstracted from articles in Hindustan Times, 28 July and 3 August 1953 - 51 -

The total area commanded by the barrage's canal system will be 1,025,762 acres (415,116 ha) of which 185,000 acres (74,862 ha) will be fed by the existing Damodar canal system. The canals, distributaries and minors will, however, be 1,552 mi (2,483 km), supplying water to the commanded area during the winter.

The food yield will increase by 349,276t per annum, of which 216,076 t will be rice. The value of this extra food at current prices is estimated at Rs 300 million. Output of straw to the extent of 17,874,600 maunds (714,984 t) is also expected.

The navigation channel, which will have 24 locks, will reduce considerably the pressure on railways. It will carry an annual cargo of 2 million tons, of which 1,500,000 t are expected to be coal.

Started in 1952, the barrage is expected to be completed by 1955 when the other projects with which it is directly linked that is, the Maithon and Panchet Hill Dams will also be ready. Water for irrigation in the main canal will be availabke in 1955 or even earlier.

While the span of the river at Durgapur is 1 mi (1.6 km), the barrage will be 2,271 ft (690 m) in length. It will be noticed that the length of the barrage is only half of the river's width. The idea is to reduce the width of the river by constructing two guide bunds on either bank in order to bring down the cost of the structure.

The left guide bund is ready and work on the right is proceeding. In order to keep the entrance to the canals silt-free, 10 of the 34 gates - five at cither end - will be for the undersluicc bays, while the remaining will be in the actual weir bays. Friction blocks or energy dissipators will be provided at the downstream end of the glacis throughout its length. The

construction is going on ahead of schedule.

/2. The Maithon - 52 -

2. The Maithon Dam

At Maithon, the next project site 65 mi (104 km) upstream from

Durgapur, the diversion channel on one end of the earthen dams to take the monsoon overflow of the Barakar river was completed in good time Before the

rains.

The 162 ft (49 m) high earth-cum-concrete dam is situated between two hills on either banks of the Barakar, 8 mi (12 km) above its confluence with the Damodar. The concrete portion, 622 ft (186.6 m) long, will be linked to the hill on the right bank and stretch across the diversion channel. Between the concrete section and the hill on the left bank will be the earth dam, 2,005 ft (601.5 m) long. Below the earth dam’s junction with the left bank, a tunnel has been dynamited through the hill to take the Barakar’s cold weather discharge. Prom a width of 25 ft (7.5 m) at the tops, the concrete spillway will fan out to a base of 350 ft (105 m) and the earth dam to 940 ft (282 m). Dikes on both banks measuring 11,940 ft (3,582 m), will hold the water in the reservoir.

The reservoir will submerge an area of 26,500 acres (10,600 ha) and store 1,104,000 acre-feet (1,362 million m3 ) of water of which 725,000 acre-feet (894 million m3) will be controlled flood storage. The area irrigated will be

270,000 acres (108,000 ha) and the power generation capacity of the plant will be 40,000 kW. The earth dam has risen to a height of 40 ft (12 m). Work on the concrete section will begin in the winter of 1953-54. The dam is scheduled to be ready by the end of 1954.

In 1933-34, on the Norris Dam in the Tennecsee Valley Authority (USA), projects 1 million cu yd (765,000 m 3 ) of earth were excavated in 18 months; Damodar

Valley Corporation engineers and workers achieved the record figure of 1.2 million cu yd (918,000 m3 ) during a period of 7 months, a commendable feat considering the limited extent of mechanization as compared to that at the Norris Dam.

/The Panchet - 53 -

3. The Panchet Hill Dam

About 17 mi (26 km) south of Maithon, work on the Panchet Hill Dam across the Damodar was begun some months ago. In locating the dam, engineers have taken advantage of a right-angle bend in the river. The bond offers a favourable site because no special construction will be needed to divert the river in order to secure a dry bed for building the dam. A diversion cut is, however, being dug a little above the bend and this will join the river a little beyond the end of the curve. Side by side, nearly one third of the length of the earth dam has risen to a height of about 30 ft (9 m).

A concrete-cum-earth structure like the Maithon Dam, the dam will be 133 ft (40 m) high. The length of the earth dam will be 1,800 ft (540 m) and that of the concrete 775 ft (232.5 m). With a breadth of 35 ft (10.5 m) at the top, the concrete dam at the base will bo 250 ft (75 m) as against

800 ft (240 m) for the earth dan. The length of the dikes on both sides and the bulkhead will be 21,315 ft (6,395 m), The quantity of water held in the reservoir will cover 22,800 acres (9,120 ha) and provide perennial irrigation to 683,850 acres (273,140 ha). The capacity of the power plant will be

40,000 kW.

4. The Bokaro Power Station

Prom Panchet Hill, there is a 110 mi (176 km) drive up the valley across a beautiful countryside to Bokaro, where is located the biggest thermal power station in the East. The road grazes the foot of a hill on which stands the famous Parasnath temple, and passes through the open-cut coal mines of Bernso. The corporation was prompted to set up the power station at Bokaro because of the presence in its neighbourhood of several open-cut mines producing low-grade coal which cannot be utilized for any other purpose.

The power house works on the high-pressure pulverized-fuel-fired boiler system, a feature new to India. Coal is reduced to very fine particles and ushered into the boiler at high pressure, so that it ignites quickly and generates sufficient heat for producing steam.

/The Station, — 54-

The station, which is situated at the confluence of the Bokaro and the Konar, was opened on 21 February 1953, when one unit of 50,000 kW began operation. In the next few months, it will be equipped with two more units of 50,000 kW each. When a fourth unit is installed, the total capacity will be 200,000 kW.

5. The Konar Project

About 17 mi (26 1cm) north of Bokaro, beyond gently sloping green hills and dales, and about 15 mi (23 km) upstream from the point where the Konar meets the Damodar, lies the Konar Dam, a concrete structure intended to supply cooling water to the Boka.ro Power Station. It is nearing completion and is scheduled to be ready by the end of the year. The 160 ft (48 m) high and 910 ft (273 m) long dam and the 12,959 ft (3,888 m) long dikes on both banks of the river are rising rapidly to their full height. At the base, the width is 200 ft (60 m) while on the top it will be 19 ft (5.7 m). The reservoir will have a storage of 260,000 acres-feet (321 million m 3 ) and will submerge 6,600 acres (2,640 ha). Irrigation will extend to 68,000 acres (27,200 ha) during the winter and 36,000 acres (14,400 ha) during the autumn.

6. The Tilaiya Dam

Nearly 30 mi (50 km) from Konar, is the Damodar Valley Corporation's first completed dam in the Barakar at Tilaiya, which was opened on the same day as Bokaro. The dam is a solid mass of concrete 510 ft (153 m) long and 99 ft (29.7 m) high from the river bed. The width at the top is 15 ft (4.5 m) and the base 127 ft (38 m) and holds 320,000 acre-feet (395 million m 3 ). During the winter it will supply water to 75,000 acres (30,000 ha) and during the autumn to 24,000 acres (9,600 ha). The power plant has a capacity of

4,000 kW.

From Konar, the approach to Tilaiya is through a break in a hill, immediately on the other side of which stretches the reservoir, a vast manmade lake. The road skirts the reservoir’s edge and at one point two hills are linked by a bridge, under which the reservoir 's water flows out to spread over a vast expanse of land.

/7. Rehabilitation schemes - 55 -

7.Rehabilitation schemes

As a result of the construction of these dams, about 32,000 persons will be displaced by the submergence of land. Steps have been taken to rehabilitate them by giving compensation in cash, or house and land. Four model villages, for instance, were ready for the residents of the tract now under the Tilaiya reservoir before it began to fill during the last monsoon. Similar villages are being planned for other projects. They represent a harmonious blending of the modern and the old and are generally liked by the villagers.

To provide land to villagers displaced by Tilaiya, 5,000 acres (2,000 ha) have been reclaimed from the eroded wilderness of the valley. In furtherance of this objective, the corporation has built six small dams at the headwater of the Damodar river system. Four such dams are in the Tilaiya region and two near Hazaribagh. These minor projects have given additional irrigation facilities.

In order to execute the work at various sites expeditiously, the corporation has since its inception built 100 mi of roads in some of the most inaccessible parts of Bihar. Elevon bridges and 160 culverts had to be constructed.

At the project sites, tranships having a total of over 1,100 permanent structures have been erected to house the staff. In addition to schools and dispensaries in some of them, which cater also to the surrounding villages, other amenities have been provided. The corporation's central soil laboratory, timber and mechanical workshops and stores and godowns are located at Maithon.

From this Rs 890 million scheme, irrigation benefits will accrue to a total area of 1,025,762 acres (415,116 ha) and the power generation capacity will be of the order of 274,000 kW. In terms of money the increase in national wealth at present rates will be nearly Rs 580 million per annum through more food, jute and power.

/The Poringalkuthu - 56 -

The Poringalkuthu Hydro-Electric Scheme1/

The first power project to benefit the Cochin part of the Travancore-Cochin State is the Poringalkuthu Hydro-Electric Scheme. This scheme known as the Left Bank Scheme, envisages the ultimate development of 48,000 kW., in two stages at Poringalkuthu on the Chalakudy river, the largest perennial river in Cochin territory, 40 mi (60 km) from its source and 26 mi (40 km) from the Chalakudy railway station, by the construction of a reservoir to regulate its flow (see figure 4). Here the river falls in a series of cascades to a depth of about 600 ft (185 m) and the scheme is planned for utilizing this head for power development. In the first stage, the installed capacity of the plant will be 23,000 kW. The whole scheme is estimated to cost Rs 26 million.

The project was originally investigated between 1918 and 1932, the present site was selected in 1947 as the most economical one; work was then started, construction and investigation proceeding side by side.

The dam

The Poringalkuthu Dam, known as the Lower Dam, is a straight gravity structure in rubble masonry, 1,200 ft (360 m) long and 86 ft (25.8 m) above the river bed, impounding a gross storage of 1,130 million cu ft (32 million m3). Its maximum width at foundation is 93 ft (27.9 m). In order to dispose of maximum floods which are in the region of 80,000 cu ft/sec (2,265 m 3/sec), draining an area of 383 sq mi (992 km2 ), seven crest gates of lowering type, 40 ft (12 m) long and 15 ft (4.5 m) deep, capable of discharging 52,000 cu ft/sec

(1,473 m3 /sec) are installed on the spillway on the left flank in addition to four undersluices, 18.75 ft (5.6 m) high and 8 ft (2.4 m) wide on the river bed, to discharge the balance. The cres+ of the spillway is 66 ft (20 m) above the river bed. The full retention level and maximum flood level are kept at the same height to prevent -damage to roads and bridges 5 mi (8 km) upstream. The reservoir, which will .spread over 700 acres (280 ha), will

/have a

1/Abstracted from an article by R. Dorai Rajan in Indian and Eastern Engineer, June 1953, p.863. - 57 -

have a shore line of 13 mi (20.8 km) and heads up 3 mi (5 km) upstream of the dam. The foundation of the dam has teen taken down to hard rock 35 ft (10.5 m) below the deepest bed level and core boring, including curtain and blanket grouting, has been done to consolidate the foundation. A cut-off trench lined with concrete is also provided at the head of the dam to check percolation of water under foundation and to serve as a key. A small drainage gallery 2.5 ft x 2.5 ft (0.75 m x 0.75 m) to collect the seepage water runs through the entire length of the dam. Another auxiliary drain 15 in x 15 in (37.5 cm x 37.5 cm) is also provided behind the drainage gallery. Two other foundation drains 15 in x 15 in (37.5 cm x 37.5 cm) are constructed at the river bed level, one below the drainage gallery and the other below the auxiliary drain. The drainage gallery, auxiliary drain and foundation drains are all connected by drainage shafts so that percolation water is collected and drained through the transverse gallery downstream of the dam. The masonry content of the dam is 2 million cu ft (59,500 m3). The cost of the dam is Rs 5.4 million.

The tunnel

Water from the reservoir is led through a tunnel cut in rock across the intervening hill for a length of 3,995 ft (1,198 m) to the penstocks. The tunnel consists of a finished rectangular section of 15 ft (3.9 m) width and 6 ft (1.8 m) height with a semi-circular top and a clear cross- sectional area of 144.4 sq ft (13.4 m 2 ). To reduce forces due to friction, the tunnel has been lined with 6 in (15 cm) thick concrete. The capacity of the tunnel is 1,200 cu ft/sec (34 cm3/sec) at a regulated velocity of

8 ft/sec (2.4 m/sec). A reinforced cement concrete cut and cover channel

380 ft (114 m) long connects the intake works with the tunnel portals. The tunnel intake works comprise the construction of a masonry entrance with two inlet gates each 10 ft (3 m) high and 8 ft (2.4 m) Wide and trash racks in front. The tunnel, which was done departmentally, cost Rs 2.4 million and is claimed to be the cheapest tunnel in India Rs 325 per running foot.

/A utility - 58 -

A utility bridge across the river just downstream of the dam connects both banks. It is 600 ft (180 m) long with reinforced concrete decking carried on ten piers, two spans of 55 ft (16.5 m) and one of 34 ft

(10.2 m) with a tramway on the top to help in transporting material during the construction of the dam.

On the other side of the hill, 144 ft (43.2 m) from the tunnel exit, is located a simple surge shaft cut in rock, 93 ft (28.3 m) high with a finished interval diameter of 50 ft (15.2 m). It is designed to absorb the surges which take place during the operation of the plant owing to sudden load fluctuation and thereby relievo the pipe lines and tunnel from dangerous presure. The surge shaft will be concrete lined and domed on top.

From the surge shaft, two low-pressure pipes each of 8.5 ft (2.55 m) internal diameter for a distance of 144 ft (43.2 m) run to the tunnel exit where one of the pipes branches into three,pipes each of 52 in (130 cm) internal diameter and with a capacity of 200 cu ft/sec (5.7 m3/sec) through a manifold. Each of these penstocks feeds one machine. Butterfly valves and venturi meters are fitted to each penstock pipe at the valve house to control and regulate the flow. The second 8.5 ft (2.6 m) diameter pipe branches into two pipes through a second manifold. These two pipes are continued up to the butterfly valves and blankflanged in the first stage. The butterfly and air valves are connected to a venturi meter fitted in each penstock about 40 ft (12 m) downstream of the first anchor.

The head from the tunnel exit to the turbines is 600 ft (180 m) and the three penstocks, 2,600 ft (780 m) long, are held in position by nine concrete anchors along the slope with a maximum incline of 20 degrees. Each piece of pipe about 20 ft (6 m) in length weighs from 3.5 to 9.5 t (maximum) and is tested in the lower reaches to 868.05 lb/sq in. The total weight of the penstocks is 1,812 t. The cost of the penstocks is Rs 5.1 million.

/a haulage - 59 -

A haulage track along the pipe-line is laid and is operated by two winches with 1 1/8 in steel rope, the drum weighing 3 t.

The power house is a reinforced concrete structure with hollow block in panels, 125 ft (37.5 m) long, 65 ft (19.5 m) wide and 49 ft (14.7 m) high and accommodates three turbogenerator sets and indoor switchgear. To facilitate handling of machinery during construction and later on for overhauling and maintenance a 70 t overhead travelling crane with a 5 t auxiliary hoist is installed in the power house.

Work on the dam is nearing completion, while the tunnel is bored for the full length and concrete-lined. It was expected that the installation of the generating machinery would commence in May 1953 and generators commissioned one after the other and the whole scheme completed in June 1954.

/ Plan for - 60 -

NEPAL Plan for the development of Nepal1/

The Indian team of experts which visited Nepal in 1952 at the request of the Nepal Government to prepare a Five-Year Plan for the country has reported that Nepal offers great possibilities for the development of forest wealth and forest industries.

Nepal has comparatively less scope for the development of agriculture. According to the team, there is also scope for horticulture, sericulture, apiculture and wool industry. Communications are the most urgent need of Nepal to open up the country for development and for proper administration. A geological survey is also necessary.

As regards hydro-electric projects, the Kali Project is of immediate importance. Preliminary estimates for this project were worked out by a British firm of engineers three years ago. This firm has asked for further investigation into the project. It has also made preliminary investigations in three other projects, namely, Tharo, Marsyhudi and Kulikhani, none of which is, however, regarded as promising as the Kali Project.

The three existing irrigation systems in Nepal consist of 103 mi (165 km) of channels covering 45,000 acres (18,000 ha) of land and supplying an annual quantity of water yielding Rs 57,000. The two works under construction will Cover about 4,000 acres (1,600 ha) and two other works under construction will cover 25,000 acres (10,000 ha). They are estimated to cost Rs 2.4 million.

In addition, the team drew up a large list of possible schemes, including 29 for the plains at an estimated cost of Rs 45.8 million. Twenty other schemes relate to the western hills. They are estimated to cost Rs 1,688,000.

The team has pointed out that the existing practice of shifting cultivation had resulted in unplanned cutting of forest trees, leading to soil erosion, /Pakistan

1/ Abstracted from an article in Hindustan Times, 1 September 1953. - 61 -

PAKISTAN Development plan for the Baluchistan States1/

The Baluchistan States Union has a total area of 81,239 sq mi (210,490 km2 ). The countryside rises from sea level to heights of 10,000 ft (3,048 m) in some parts. The temperature ranges from below 0°F to over 100°F in different seasons of the year. The area contains various ranges composed of different types of soils from alluvial silt to fissured rocks. The total population is 552,000.

The area is interspersed with non-perennial rivers which have a heavy run­ off of water during the rainy seasons. The rainfall varies in different parts of the Union from 3 to 15 in (762 to 381 mm) a year. Much of this water percolates straight into the heavily fissured rocks and the alluvial silty soils of the flat- topped valleys, raising the underground water table. The balance runs to waste in the absence of any dams across the rivers to store this water in the catchment area. The narrow river gorges coupled with the swift water run-off afford favourable opportunities for the development of hydro-electric power. Large tracts of land with gravelly loam and alluvial silty soils in valleys lie undeveloped with equally vast areas of undulating fissured rocky slopes, geologically rich in mineral deposits.

Preliminary investigations in this area revealed that in the State of Kalat alone about 3 million acres (1,214,070 ha)could be brought under cultivation. At present wheat, millets, maize and cotton are grown in different parts of the Union, There are orchards producing mangoes, apples, grapes, peaches, dates and other kinds of fruits. Sheep-rearing and coal-mining are being carried out in the Union and the annual yield of wool in the Kalat area alone is estimated at 1,230,000 lb.

The utilization of water resources, both surface and underground, by the construction of dams in the rivers, the storing of the swift flowing waters in the rainy seasons in the catchment area and the sinking of tube-wells to tap the underground water table, would enable large tracts of alluvial silty valley to be

/brought under

1/ Abstracted from-an-article in Pakistan News Digest, 1 September 1953. - 62 -

brought under cultivation for the production of various types of food crops. The undulating topography of the land with its slopy hilly sides lends itself to the establishment of extensive orchards.

With the nucleus of sheep-rearing industry existing in the area, development of extensive sheep ranges coupled with wool production is possible.

Large deposits of brown coal, chromite manganese, phosphate, sulphur, lead and other minerals found in this area in the course of a preliminary geological survey could be exploited both for domestic use and for export. The long sea coast with natural sites for harbours and rich fishing potentialities would lend itself to the development of sea communications and development of coastal traffic. The establishment of a port on the sea-coast and the development of land routes connecting the various centres of the Union with Karachi would provide the requisite outlet for the internal and international trade in commodities and goods resulting from the economic development of the area.

An agreement between the Governments of Pakistan and the United States of America has been signed recently which envisages the development of the following projects:

1. Conservation and development of all available surface and underground water supplies for domestic, agricultural and possible future industrial use

2. Range restoration and management

3. Afforestation of suitable areas

4. Improvement of livestock

5. Increased and improved fruit production

6. Exploration and development of mineral resources

7. Development of a secondary port

8. Development of coastal communications

9. Expansion and modernization of the fishing industry 10. Improvement of public health and sanitation

11. Construction of access roads including a road from Karachi to Quetta.

/For the - 63 -

For the first phase, comprising detailed investigation into the technical and economic feasibility of the projects and drawing up of details the US Technical Co-operation Administration (TCA) has committed US$300,000 and the

Government of Pakistan will contribute Rs 800,000. Further sums will be committed shortly. The TCA will furnish a project adviser and such additional technicians as may be required, along with supplies and equipment necessary for effective implementation of projects.

The Karnafuli Hydro-electric Project1/

In spite of Pakistan’s current economic crisis caused by two bad crop years and slumps in cotton and jute prices, only one major multiple-purpose project is under way at present. This is the Karnafuli Dam Project in East Pakistan, where 10,000 men are working. It started in 1952 and is to be completed in five years.

Located on the Karnafuli river 35 mi north of Chittagong in East Bengal, the dam will be earth-filled and rock-faced. It will be 120 ft (36 m) high and 700 ft (510 m) wide, and will vary in thickness from 867 ft (260.1 m) at the bottom to 25 ft (7.5 m) at the top. The vertical lift is 100 ft (30 m), while the maximum discharge will be 400,000 cu ft/sec (12,000 m3/sec) and the minimum 5,000 cu ft/sec (150 m3/sec).

Flood discharge will be handled by two spillways on one side of the dam. Model testing is in progress to determine gates and designs which are to be used.

The 160,000 kW generated by four 40,000 kW turbines will provide electricity for the southern half of East Pakistan. It is expected that 1 million acres (400,000 ha) of land will be irrigated by pumps operated with the cheap power. The expansion of the industrial city of Naraingunj is likewise foreseen. Over 100 mi (160 km) of navigation facilities would bo improved, allowing for a tenfold increase in the extraction of forest produce.

The project is estimated to cost US$ 57 million. / Underground water

1/ Abstracted from an article in Engineering News Record, 18 June 1953, p.59. - 64 -

Underground water reservoirs1/

A scheme for constructing underground barriers along the beds of the Nai Baran and Baran rivers in the Kohistan area of Dadu district is awaiting final sanction of the Sind Government. The Sind Chief of Ministers is understood to have given his sanction to the scheme and would place it shortly before the cabinet for final approval.

The scheme, which would be part of the Dadu and Darwat Dam Schemes, envisages the construction of underground barriers to build huge underground water reservoirs. Under the scheme, barriers would be constructed at more than four points in the bed of the Baran and the Nai Baran rivers, below the proposed dam sites. The barriers would be constructed at points where the sub-stratum is rocky and does not permit water to percolate through. The barriers would then stop the undercurrent and store up water in the shape of underground reservoirs.

It is proposed to dig wells in the reservoir areas and pump water to low and high-lying lands for irrigation purposes. More than 20,000 acres (8,000 ha) of land would be made cultivable by the water obtained from these underground reservoirs.

The Ganges - Kobadek Scheme

The work on the Ganges-Kobadek Scheme, a brief description of which was given in the Flood Control Journal [January 1953 (ST/ECAFE/SER.C/14) p 21], was expected to begin in November 1953. A portion of the first unit, which comprises the northern portion of Kushtia and a part of Jessore, totalling about 200,000 acres (80,000 ha) of land, is expected to be completed by 1955.

It will involve an expenditure of about Rs 250,000. The full unit will irrigate an area of 2.4 million acres (960,000 ha) and cost about Rs 500,000. The total area of land to be irrigated by the Ganges-Kobadek Scheme will be 2.2 million acres (880,000 ha).2/

/The Taunsa

1/ Abstracted from an article in Dawn, 24 August 1953. 2/ The figures given here are based on those given in Dawn, 5 August 1953. - 65 -

The Taunsa Project1/

The work on the gigantic Taunsa barrage project across the Indus, for irrigating 1.4 million acres (560,000 ha) of barren and barann2/ land in Dera

Ghazikhan and Muzaffargash districts, is proceeding briskly. The project is expected to be completed at an estimated cost of Rs 100 million.

According to plans, the barrage will be constructed on the Indus at a place 180 mi downstream of the Tinnah barrage at Kalabagh. The new barrage will form the source of two canals, which will between them irrigate nearly 1.4 million acres (560,000 ha) of land in the two under-developed districts in the province.

The existing inundation canals in the area will be remodelled and connected to the proposed irrigation scheme by means of two new canals.

The Gjlghit Projects3/

The Pakistan Government has sanctioned a sum of Rs 456,000 for the execution of four new irrigation projects in the Gilghit Agency. The projects when completed are expected to bring more than 7,000 acres (2,800 ha) of land under irrigation. The work on these projects was expected in June to start shortly.

The projects are: Parri Channel, Bunji Channel, Chilas Than Nullah Channel and Hunza River Channel. The Parri Channel project is stated to be the biggest and it alone will cost about Rs 200,000.

These projects will supplement five already completed water channels which have brought under cultivation large areas of barren land. They are: Doyan Channel, Gwikote Channel, Pakorai Channel, Taipur Channel and Chorti Channel.

/Repairs to

1/ From Dawn, 25 August 1953. 2/ Land on which crops are grown on rain water only.

3/Abstracted from an article in Dawn, 22 June 1953. - 66 -

Repairs to the Lloyds Barrage1/

Repair work on the Lloyds Barrage at Sukkur, which began in 1950 when cracks appeared in it, has almost been completed. Cement grouting to the main piers of the barrage and grouting of regulators in it to save them from rust have been completed. Special repairs to the barrage gates have also been carried out.

The over-all repairs to the barrage have cost the Sind Government about Rs 5 million.

New canal for the Punjab planned2/

To make up for the water shortage in the Sutlej Valley Canals, the Punjab Government has decided to construct a new canal. This canal will take off from the river channel at Marala Headwork and fall in the river Ravi. The canal will be completed in two years and cost Rs 70 million. Two irrigation projects for the Punjab approved3/

The Punjab Grow More Food Emergency Committee has approved two short­ term irrigation projects to irrigate over 17,000 acres (6,800 ha) of land at a total cost of Rs 474,000. Reclamation operations on one of these schemes, which provides for the installation of 51 flood outlets on Raya Branch, are already in progress.

PHILIPPINES

The Padada River Irrigation Project

The Padada River Irrigation Project, the first national gravity project to be constructed in Mindanao, is part of the present administration's programme aimed at increasing rice production. It is designed to irrigate 3,000 ha (7,500 acres) of agricultural land, at present devoted mostly to maize, but which upon operation of the irrigation system, is expected to be planted to rice during the wet season and rotated to maize, mongo and onion in the dry season. /The project

1/ Abstracted from an article in Dawn, 21 July 1953. 2/ Abstracted from an article in Dawn, 1 August 1953. 3/ Abstracted from an article in Dawn, 5 August 1953. - 67 -

The project was conceived as long ago as 1946 when the necessary preliminary investigation for its feasibility was made; this was immediately followed by a topographic survey of the whole irrigable area, the location of the proposed main canal and laterals, and finally, the preparation of plans and estimates which were completed in 1950.

All construction work was done under contract, with the exception of the construction of the turnouts which was undertaken by the administration. Funds for construction were obtained mainly from loans by the Central Bank. During the final phase of construction, however, the project was granted MSA - PHILCUSA1/ aid.

The following are the salient features of the project

1. Irrigable area - 3,000 ha (7,500 acres) [consisting of 2,000 ha. (5,000 acres) now irrigable plus 1,000 ha (2,500 acres) of coconut land expected to be converted to rice lands]

2. Barrios served - Lapolabao, Bawa, Sinayawam, Hagonoy, Sacub, Mayahay, Balutacay

3. Total length of main canal and laterals - 31.5391 km (19.712 mi)

4. Cost of project - ₽ 1,655,000

5. Number of land-owners directly affected by the system - 450

6. Date when construction was begun - 13 December 1950

7. Date when project was formally opened - 22 July 1953

6. Quantity of cement used - 29,029 bags

9. Quantity of steel used - 187,022 t

10. Volume of Class A concrete used - 3,170.4

11. Volume of earth excavation and burrow in canals and laterals - 246,617 m3

/12. Sources of funds

1/ Mutual Security Agency [now called Foreign Operations Administration (FOA)] and Philippine Council for United States Aid. - 68 -

12. Sources of funds (a) Central Bank funds ₽ 483,763

(b) Public Works appropriations ₽1,065,660

(c) Counterpart Project No.34 ₽ 85,745

(d) All steel gates for headwork, canals structures and turnouts furnished by MSA ₽ 19,858.

/ VII. PROJECTS OUTSIDE - 69 -

VII. PROJECTS OUTSIDE THE REGION THE PARAIBA-PIRAI DIVERSION SCHEME (BRAZIL)1/

The Paraiba-Pirai Diversion Scheme (see figure 5) is designed to divert up to 5,650 cu ft/sec (169.5 m3/sec) from the Paraiba river and to convey it over a distance of 20 mi (32 km) to a point where it can be used in an existing power plant and also in a new underground plant under construction in the mountain side nearby. The diversion point is at Santa Cecilia, 1,25 mi (2 km) upstream of Barra do Pirai, 100 mi (160 km) above an existing run-of-river plant at Ilha dos Pombos operating under a head of 105 ft (32 m) with a total generating capacity of 162,000 kW.

Two pumping stages are required to raise the water 148 ft (44.4 m) to the valve chamber at Fontes, the first stage being located at the Paraiba offtake and delivering through a tunnel and an open canal to a second basin - the Santana Reservoir - formed by a dam across the Pirai and receiving the flow of the Pirai river. From this basin, the second and main pumping stage raises the water to a reservoir formed in the valley of a smaller stream - the Vigario - where it flows through a canal and tunnel to the valve chamber.

This development will somewhat reduce the output from Ilha dos Pombos, but the diverted water will generate at Forcacava several times the energy that it could generate at Ilha dos Pombos.

The dam at Santa Cecilia is 853 ft (255.9 m) long and consists of a

Concrete spillway section, the left-hand end of which is closed by an earth embankment 279 ft (83.7 m) long. The spillway section consists of a base slab and heavy piers to take nine tainter gates, eight being 20 ft (6 m) high by 60 ft (18 m) long to control the main flow, and the ninth, 10 ft 6 in (3.15 m) long, to pass compensation water. The normal spillway capacity is 130,000 cu ft/sec

/(3,900 m3/sec),

1/ Abstracted from an article in Water Power, August 1953 p. 287 To Sao Paulo To Sao To Pirapora Paulo /

Sta. Cecilia R. Dam Sta. Cecilia Pump House

To Campos

Barra Do Pirai

R. Piral - 70

Dol road to Sao Paulo Vigario Santana To Rio de Janeiro Pump House Reservoir

Vigario Reservoir Vigario Vigario Pump Reservoir House R.Parai _Santana Vigario Canal Vigario Tunnel Reservoir

Valve Chamber Forcacava Machine Hall Sta.Cecilia Pressure Shaft Vigario Tunnel Tunnel Sta. Vale Existing Gecilia Chamber Power House Pump House Machine Hall 0 1 2 3 4 5 Km. To Rio de Janeiro Scale

Fig.5. Map and profile diagram of the Paraiba-Pirai diversion. - 71 -

(3,900 m3/sec), which is substantially above the maximum recorded flood, and, in fact, the open gate area is larger than the original channel cross section, so that the dam will not produce any back-water effect during floods.

Another important feature is the manner of dealing with the high proportion of sand and silt, and one of the main problems was to prevent this abrasive material from entering the pumps. To ensure that the main bed load is passed downstream, the sill of the dam has been placed below the level of the normal river bed, and the pump station has been protected by silt-deflecting walls (see figure 6) which were designed on the basis of model tests. During floods, when most or all of the tainter gates are open, the outer silt wall deflects most of the silt through the gates, and any that finds its way over this wall is sluiced out by the eddies formed between the outer and intermediate walls. During dry periods, the space between the walls acts as a settling chamber, and the deposit is readily sluiced out by a slight opening of the end gates.

The Santa Cecilia Tunnel pierces the range of hills separating the

Paraiba and Pirai valleys and is just over 2 mi long. It is of horseshoe section,436 sq ft (39.2 m2) in cross-sectional area, and is concrete-lined throughout.

It is of the free-flowing type and discharges into a canal section, 8,200 ft (2,460 m) long, leading to the Santana Reservoir. The canal is in three approximately equal sections, the first and third being in earth and the central section in rock. Three large transition structures were required in the canal between the Santa Cecilia Tunnel and the Santana Reservoir, and the two expansion transitions - from the tunnel and from the rock section - were provided with splitter walls to maintain a uniform velocity over the section and to minimize scour.

The Santana Dam is 36 ft (10.8 m) high and has a length of 360 ft (108 m), of which 198 ft (59.4 m) consist of earth embankment. The spillway section consists of two tainter gates identical to those at Santa Cecilia, and a small broome gate. The Santana Reservoir has a capacity of 18,000 acre-feet (22.2 million m3) and covers an area of about 10 sq mi (25.9 km2), at a water level of 1,191 ft (0.4 m).

/The Vigario 8 spaces at 70.54=564.32 Pump House To Rio de Janeiro i' !

ba ib a r a P i r e liv O Earth Dyke Penstocks Approx. 1166.34 Tunnel

FLow 9 Bays at 22.31 =200.79 Silt Deflecting Railway Tracks Walls To Sao Paulo -

Penstock Tunnel 72

Top of 1166.34 Earth Dyke Outlet Inlet - Structure Structure

A/Switching Structure

SECTION A-A

Scale: 0 100 200 ft.

Fig. 6. General arrangement of Santa Cecilia dam, pump house, penstocks, and tunnel inlet structure. - 73 -

The Vigario Reservoir, lying at 1,306 ft (391.8 m) above sea level, has an area of only 840 acres (340 ha) but its storage capacity is no less than 37,000 acre-feet. (45.6 million m3). To form the reservoir, two earth dams had to be constructed, one 134 ft (40.2 m) and the other 118 ft (35.4 m) high.

From the Vigario Reservoir, the flow is by gravity to the Forcacava valve chamber through the Vigario Canal and Tunnel. The canal is 4,500 ft (1,350 m) long, 46 ft (13.8 m) wide at the bottom, and has 312 side slopes,

It is chiefly in earth and is concrete-lined. At the entrance to the tunnel is a reinforced-concrete intake structure equipped with racks and two wheel-mounted gates. The tunnel is 1,970 ft (591 m) long and 615 sq ft (55.35 m2) cross- sectional area, and has a discharge capacity of double the general diversion capacity to take into account the system load factor.

Forcacava will have an aggregate capacity of 330,000 kW, and will be one of the largest underground stations in the world. The future units will have an aggregate capacity of 390,000 kW. The turbines will be of the Francis type, operating under a head of 1,130 ft (339 m).

In the near future it is proposed to build a further 90,000 kW station using the remaining head between Fontes - Forcacava tailrace and sea-level. When the scheme is complete, its generating capacity will be raised from 1,570 million kWh to over 4,000 million kWh per annum.

THE KANSAS RIVER FLOOD-WAY PLAN (UNITED STATES OF AMERICA)1/

The Kansas River Flood-Way Plan was recently discussed at the 73rd Annual Convention of the American Water Works Association held in Grand Rapids, Michigan.

The central project in the Army Engineers Kansas River Valley Flood Control Programme, the $80 million Tuttle Creek Dam, was started in October 1952. The $2,2 million first phase of the project is located on the Blue River, 6 mi from Manhattan, Kan. Kirwin Dam, a $17.8 million project on the north fork of the Solomon river, a tributary of the Kansas, is 10 per cent finished. A $7 million contract for further work was awarded in January 1953 and the contractor received notice to proceed on 5 February from the Bureau of Reclamation. / I n the summer 1/ Abstracted from articles in Engineering News Record, 5 March, 23 April, 21 May and 18 June 1953. - 74 -

In the summer of 1952 the State Government of Kansas appointed a three- member group of experts to evaluate the programme of federal agencies - The Army Engineers, the Bureau of Reclamation and the Department of Agriculture - which is a very rare instance indeed., just when the State’s dispute over big-versus- small dams for the control of floods in the Kansas river basin was at its height. The survey board has recommended that construction on the three big federal dams mentioned above should stop immediately. Instead of further dam construction the survey group urges that attention be focused on flood-way improvement (an increase in channel capacity) along the Kansas river. It recommends a three point programme:

1. Protection of urban areas by deepening and widening of channels and by construction of higher set-back levees

2. Control of flood-plain occupancy through flood-plain zoning

3. Better flood forecasting.

It is estimated that this programme would cost about $200 million, as compared with an outlay of more than $1,000 million for the proposed federal programme.

In support of the flood-way improvement recommendation, crux of the board's proposed programme, the report stated: "The situation is different in Kansas than in Ohio where dams in the Miami Conservancy District are close to the cities protected. Here, the flood-producing rains fall downstream near the cities where the dam sites are not available".

It notes that Kirwin and Webster Dams, now under construction on the Solomon river, are more than 400 river miles (640 km) and 82 river hours from Topeka, Kan. Combined, they would have cut only 800 cu ft/sec (24 m3/sec) from the peak Topeka discharge of 469,000 cu ft/sec (14,070 m3/sec), 13 July 1931.

"Flood-way", the committee report said, "would provide for minimum confiscation of land, preferably only that land which is in the area to be protected. For urban areas, they are the only works which can guarantee a safe handling of large volumes of water through such areas."

/The major share - 75 -

The major share of the cost of the proposed flood-ways and levees would be spent to protect Kansas City., and Topeka, $134 million at the former and $49.7 million at the latter. Other large projects would include: Manhattan, $5.1 million; Lawrence, $3.1 million; Salina, $1.4 million; Beatrice, Neb,

$1 million; Junction City, $817,000, Abilene, $708,000 and Marysville, $450,000.

Within their less than $200 million cost estimate, the consultants provide for projects at 37 other urban sites.

"The required flood-way capacity", the report declares, "should be provided by widening the existing channel by setting back the levees and flood walls along one bank of the river only; preserving, in so far as practicable, existing levees and flood walls along the opposite bank; by excavating the elevations above the standard low-water channel and the new levee lines, and by increasing to a minimum extent the heights of the existing levees and flood walls".

Recommendations call for eliminating "all major obstructions to flow at high-river stages". This would involve lengthening six railway bridges at Kansas City and one at Topeka; relocating a railway bridge at Topeka and one at Manhattan; replacing the Kansas Avenue bridge at Topeka; and lengthening five street bridges in Kansas City.

Army engineers criticize the report of the consultants on the following main counts:

1. Flood-way plan gives no protection to rural areas in flood-plain;

2. The report minimizes erroneously the flood damage to farms, highways, railways and other public utilities in rural areas;

3. Dumping Kansas river floods directly into the Missouri without any detention would expose downstream lands to overflow or require expensive revision of protective works;

4. Costs cited are not realistic. Actually the currently planned system of 36 flood-control reservoirs and 21 local protection projects would cost about $700 million, while the estimate of $200 million for the flood-ways appears too low;

/5. The present - 76 -

5. The present basic plan would furnish protection in the Kansas river valley for a greater potential flood than that of 1951, while the flood-way proposal assumes the 1951 flood as the standard for design;

6. Contention by the consultants that a comprehensive system of reservoirs cannot be operated successfully is disproved by the experience in the Ohio river basin and other great valleys;

7. The report fails to test its proposals on a basis of benefit-to-cost evaluation;

8. In assuming that the Federal Government would buy the needed real estate for the flood-ways, the report disregards the national policy established by Congress;

9. In suggesting that present construction of reservoirs like Tuttle Creek, Kirwin and Webster be held up until all conflicts arc settled, the report ignores the long delay that would occur in furnishing needed protection.

What worries the army engineers most is that revival of the discarded flood-way plan has confused the thinking of the people and their public officials in Kansas and elsewhere. If the report is not properly answered, they fear that flood protection in the Kansas river valley and the entire Missouri basin will suffer a severe setback and serious delay.

At the Annual Convention of the American Water Works Association, one of the consultants, answering objections of the Corps of Engineers to the flood-way plan, denied that damaging velocities would result from the proposed works. He said velocities in the peak 512,000 cu ft/sec (15,360 m3/sec) discharge at Kansas City in the catastrophic 1951 flood reached. 14.6 and 17.8 ft/sec (4.4 and 5.3 m/sec) at points within the city; higher levees and a wider channel (1,500 ft (457 m) instead of 750 ft (228 m) would carry the 1951 flow at velocities more of the order of a 3 to 10 ft/sec (1 to 3 m/sec).

The consultant admitted that the control-without-retention scheme for the Kansas would not cut flood flows to be imposed upon the Missouri and, further downstream, on the Mississippi. He said that cities from Kansas City to St. Louis, Mo., simply would have to provide the some sort of flood-ways.

Pointing out that the Army's 34 or 36 planned reservoirs, if built, would have cut but 225,000 cu ft/sec (6,750 m3/sec) from the flow at Kansas City in 1951, he declared this would have brought it to within 35,000 cu ft/sec (1,050 m3/sec) of the size of the 1903 floods. /Dredging and - 77 -

Dredging and maintenance would be costly on the proposed flood-ways past cities but maintenance would be cheaper than operation of the basin-wide reservoir plan of the federal agencies, he contended. In fact, he expressed the opinion that operation of such far-flung system of reservoirs anywhere near the theoretical plan is humanly impossible.

Flood-way past cities would provide no protection for rural areas, but the consultants maintain that the average $6 million annual flood damage to rural areas of the farming State is more than offset by improved fertility in the land due to floods.

If the cities, where 76 per cent of the damage was done in 1951, can be protected by $200 million worth of flood-ways, it is uneconomic to spend the extra $650 million envisaged in federal reservoir plans to protect acreage at a cost per acre exceeding the land's value, he argued. The reservoirs planned would flood or take out of use 450,000 acres (182,108 ha), half as much land as was inundated in the 1951 disaster, he added.

What the consultants propose in effect is a return to levees, as proposed by the Army engineers up to 1936. While levees at that time were planned for a flood of 1903 magnitude (260,000 cu ft/sec (7,800 cu m3/sec) at

Kansas City), they now proposed levees and channels to hole a 1951 flood (512,000 cu ft/sec (15,360 m3/sec) with a reasonable factor of safety. It is realized that local participation in the cost of needed levees would be more than could be conveniently afforded by individual municipalities. But they suggested that conservancy district organization (such as on Ohio's Miami river)

could lead to a financing solution.