|
|
Printer-Friendly Format |
Sindh Educational Trust
Hyderabad, Sindh,
2002.
TABLE OF Contents
INTRODUCTION
Chapter no. 01
The neglected riverain area of Sindh: the present situation and suggestions for development.
The Riverain Area.
Frequency of peak floods at Sukkur, for the year 1901-1976.
Indications of aerial photographs.
Roads.
Constraints to agriculture in Riverain area.
The present position of inundation water.
Population.
Tube-wells in the Riverain area.
Agriculture land.
Existing agriculture.
Forest land.
Animal husbandry.
Tube-wells for reclamation of the riverain agriculture land and forests
Consequences of ground water development in riverain area.
Occurrence of fresh ground water in riverain areas in Sindh.
Provision of water for the area having saline ground water.
Transportation of fresh water to the brackish water area.
Mining of water in riverain areas.
Riverain area between Kotri barrage and the Sea.
Chapter no. 02
Water requirement of crops in riverain area.
Assumptions.
Behavior of regenerated water in autumn, winter and spring.
Size of tube-well.
Protection of tube-wells during floods.
Organization for installation and maintenance of tube-wells.
Supply of Electric power in the riverain area.
Is seepage-water a loss?
Chapter no. 03
Present tube well technology for riverain areas: Limitations and solutions.
General.
Tube-wells for riveraina areas.
Failure of tube-wells.
Limitations of centrifugal pumps for pumping water from Dhoros and ditches.
Solution to the problem of pumping from Dhoros.
Diesel engine as prim-mover.
Chapter no. 04
Typical proposed tube-well design of WAPDA for Guddu-Sukkur riverain areas.
Rabi.
Kharif.
Crop yield projections by WAPDA for 2001 AD (1976 projections).
Water requirement at watercourse head as calculated by WAPDA (1976).
Potential for future development.
Fresh ground water.
Inventory of existing water sources (tube-wells and pumped Dhoros).
Statistics of riverain area, Kashmore to Sukkur.
Distribution of population between Guddu and Sukkur.
Fish varieties.
Chapter no. 05
Riverain area as ground water bank.
What is ground water bank.
Deposit, withdrawal and overdraft from ground water bank of 10 million acre feet.
Depositing in the ground water bank.
Withdrawals form ground water bank.
Overdraft from ground water bank.
Advantages of ground water bank compared to other storages.
Surface water development versus ground water development.
Advantage of ground water storage as compared with surface water storage.
Ground water infiltration below Kotri barrage.
Tail end Barrage.
Chapter No. 06
Ground water in Sindh and its position in the near future.
Chapter NO. 07
Scheme of Sindh government for installation of tube-wells in Sindh.
Chapter no. 08
Lining of canals and watercourses.
INTRODUCTION
I was invited to attend and speak at a conference at Badin on 27th July 2000 on “Whether or not to construct Kalabagh Dam”. The next day, the Daily “Kawish” reported that I spoke against construction of Kalabagh Dam, and the speech did not mention any thing on or about Kalabagh, and I wrote a letter to the DAWN, which was published by them as is reproduced below.
Facts about groundwater in Sindh.
(i) In Sindh, fresh groundwater is only in 10% area, but even this is underlain by brackish water, which rises every time pumping is done and with pumping for 30,000 to 40,000 hours, all this water will turn brackish. This is going to happen soon and there will be no fresh water tube-wells in Sindh.
(ii) If 4,800 proposed tube-wells are installed in riverain area, they would pump huge quantities of groundwater each year. This quantity of water would need annual replenishment and such a quantity is neither available, nor can be spared.
(iii) When existing fresh ground water goes saline, we would need extra surface water to maintain existing cultivation, and this has to be provided.
Parts of my speech were also shown on the PTV on the very day.
I want to point out that the reporter did not convey the correct views expressed by me.
M.H. PANHWAR
Karachi,
11 August, 2000.
Actually, I was called upon to speak at the conference only for five minutes, and on the subject “Ground Water in Sindh” which I have been investigating and studying for the past fifty years. A summary of my findings on the subject could only refer to and highlight the seriousness of the plight of the Riverain area of Sindh in case annual floods failed to visit the area and also the need and availability of extra water in the shape of fresh ground water in the said area, which was already fast turning saline. The tragedy is that Sindh believes that WAPDA is taking sides and Sindh Government has not given a serious thought to the problems of Sindh’s riverain (Katcha) area. The local residents in the area being small minorities in adjoining Talukas have no political voice and the politicians returned to Assemblies have no full awareness of their plight, and sadly enough they do not know the solution of their problem. “Ground water” has not been much of a subject to be understood and explored by the Engineering or Irrigation Departments of our Universities or even of Governments. The one time Government supply agencies and technical services working as drilling contractors for the farmers have today lost involvement or even capability. I have written these pages in defense of the neglected area and have pin-pointed and dwelt on the problems for the readers in a layman’s language. The highlights of what this book-let discusses in some details are:
(i) The riverain or Katcha area of Sindh between Kashmore and its Indus delta up to the sea coast, within the Flood Protective Embankments, is 2.112 million acres, which is roughly divided into the present and the abandoned river channels (600,000 acres), forest lands (450,000 acres), roads, settlements and government structures (50,000 acres), agriculture land (1.0 million acres, of which more than 60% is Kabuli or private land and the rest is Nakabuli or Sindh government land).
(ii) The exact figure of the Nakabuli land is not known as some of it has been leased out to various individuals, parties and agencies. The forest department also keeps on leasing out the land.
(iii) Before the opening up of Tarbela dam in 1973, the Katcha area received 300,000 cusecs of water almost every year (98% of years), 400,000 cusecs in 86% years, 500,000 cusecs in 77% years, 600,000 cusecs in 55% years, 700,000 cusecs in 28% years and 800,000 cusecs and above or super-floods in 13.3% years.
(iv) On the preserved moisture left by yearly flood water were raised forests, horticultural crops (melons and vegetables) and field crop (wheat, oil seeds) in Rabi.
(v) Area flooded and not under Rabi crop grew luxuriant grasses and pastures, and even in areas not flooded, pastures were supported by capillary action of moisture rising up from water table, and on it thrived animal husbandry, not only animals of Katcha area but also those brought form adjoining barrage areas and invariably from Thar and Kohistan from March to July.
(vi) Wahurs, Dhoros, Dhoris (abandoned channels) and active river channels produced abundant fish and fauna, and fishing was a large industry in Sindh.
(vii) Permanent population of Katcha area was 750,000 in 1972, but a large number of migratory and temporary people of out-side areas too were engaged in the cutting of outworn or excess forest trees, tens of thousands, in making wood products, in making wood products in animal husbandry, fisheries and in plying tens of thousands of boats as means of river transport and fishing.
(viii) Jobs appropriate to those for the riverain area in hundreds of ways had made people of the Katcha and adjoining areas prosperous.
(ix) Boatmen were once hit badly by railway traffic since its inception in 1861. Being directly in competition with the government owned railways, but the river, their lifeline, existed and they survived. The boatmen in Sindh are today being decimated because of Indus in its passage through Sindh, and Sindh’s hundreds of lakes, are being devastated and de-watered and literally killed. And the governments of the day care a hoot about it all. Hundreds of river ports have decayed and gone out of service and tens of thousands of the boat-men and men of fishing communities are languishing in penury. The government establishes Municipalities, Notified Area Committees, important mundies and settled business communities and workmen therein, are flourishing but not the boatmen and others dependent for living on the river since thousands of years past.
(x) New canals were being constructed and old ones extended and the area under cultivation was being increased from 900,000 acres in 1843 to 3.0 million in 1900, but no provision was made for settlement of boatmen as farmers on new lands, which as per general policy were being sold or allotted to big land-holders as they helped the government in maintaining law and order and helped in execution of government policies. Exactly the same “care a hoot for it all” is being adopted towards, the fate of the river, and the vast human, animal and vegetable populance that it feeds and sustains for the rest of us all.
(xi) The flooding of Katcha area annually with minimum of 300,000 cusecs in 98% years and 400,000 cusecs in 86% years, gives the area historical right on water for agriculture, animal husbandry, forest and fisheries, and this right must be met at 100% by the government. Some fishermen at Rohri had fishing rights to catch pala (hilsa) fish on up streams of Sukkur barrage to Khwaja Khizir’s island. Sukkur barrage had no fish ladder and fishermen asked for “fishing rights” south of the barrage head-works. It took 30 years to settle the case. Mean while fish ladder was provided for at Kotri barrage, but alas! That too failed to work as it was not designed on actual study of movement of hilsa. Fishermen there asked for right on the down stream of Kotri barrage, but before it was accepted; water flow down stream of Kotri barrage dwindled into occasional streaks only.
(xii) Kotri barrage depended on its supply of water in Rabi season on seepage of water from lands within and out-side Flood Protective Embankments to the river channels and this regenerated water had minimum discharge of 3,000 cusecs at Kotri barrage, in addition to filling Wahurs, Dhoros, Dhoris and supporting fish and agriculture, wherever pumping was resorted to form Dhroros and the main channel. Today due to non-flooding of the riverain area, situation has changed and the scanty seepage from the embankments take place only from September to January, while form February to June embankments in turn absorb water form the main channel, if available. This pattern has affected availability of water almost directly down stream both of the Sukkur and Kotri barrages.
(xiii) During the inundation season flood water not only recharged ground water in the Katcha area but also in adjoining barrage area. Now in the reverse situation ground water in adjoining barrage areas in going to be depleted from root zone, and needing more irrigation water for raising crops.
(xiv) The riverain area in Sindh has fresh ground water in 50% area only and it is saline in the rest 50% of its area. In order to raise only a single Rabi crop on tube-wells in the 50% of area, 1.8 MAF (million acre feet) of water is needed. For the rest of the 50% area surface water required is 2.7 MAF as its transportations losses would be 50% of water actually delivered to the field. This 50% is conservative figure as WAPDA’s calculations make it 100%. Total water requirement shall be 4.5 MAF for 1.45 million acres of land under agriculture and forestry.
(xv) This does not include water needed to dilute sea water, along the coast to regenerate crustaceans water, along the coast to regenerate crustaceans (shrimps both giant and sea water lobsters and crabs), hilsa and other brackish water fishes and mangroves, which have dwindled to almost 5%. Today 100 boats catch the same fish as 5 boats were catching before commissioning of Tarbela dam.
(xvi) It would be uneconomical to raise forests on tube-well water. Forest land can be distributed among landless farmers at 16 acres per family from riverain or adjoining areas to overcome resentment among the people for making Land Reforms un-Islamic. There is also an un welcome streak of thinking that land may be leased out to parties from other areas or given to foreigners in the name of ‘Corporate Agriculture’.
(xvii) A tail end barrage is needed to stop flow of sea water in the river bed. When water becomes surplus it could be diverted by two canals to fill lakes in coastal area for water needs of human settlements and animals.
(xviii) Some assured quantity of water is to be allowed to flow to the sea year around to protect environments as mentioned in (xv) above.
(xix) Fresh ground water area in Katcha is in about 50% of total area of 2.1 million acres i.e., in 1.05 million acres. It is a bank of ground water in which water can be deposited during inundation season of a few weeks to about two months and withdrawn my time. This bank also has ability to provide overdraft in form of withdrawal over the deposit, during a particular year by allowing discharge from depth up to 50 feet economically, by spending more on power, a kind of “interest” and again charging the storage bank in the coming year or two. Withdrawal can be up to 10 MAF (million acre feet).
These in brief are the problems of Katcha area of Sindh, which need to be studied at top priority level, keeping in view the following:
(a) Along with the water requirement of the area, environmental study of the whole area may be undertaken by foreign consultants appointed by the Government of Sindh with assistance of aid agencies. The local consultants lack know-how, and Sindh strongly believes that WAPDA is taking sides, and therefore foreign consultants have to be responsible directly to the Sindh Government.
(b) Environmental impact of dams on Indus and its tributaries and their effects on the coastal area may be studied by foreign consultants and minimum flows to the sea worked out by similar consultants appointed by the Sindh Government.
(c) Effects of non-availability of water in the Indus, and tidal encroachment in the bed of river, which in turn has made adjoining areas unfit for cultivation and grazing, deterioration of shallow fresh water dug-wells, shifting of population and desertification, may be studied by foreign consultants, appointed by the Government of Sindh.
(d) Design of a tail end barrage to stop intrusion of sea water may be assigned by the Government of Sindh to foreign consultants.
(e) The best designs for tube-well in riverain areas may be studied and work assigned to foreign consultants. This should be the standard design to be enforced by law by the government.
(f) Sindh has very limited fresh water and it is slowly turning saline. Study of this may be undertaken to work out extra surface water required to supplement it in areas, where water has turned saline to save at least the tree crops raised on this water.
(g) A master plan is to be prepared to execute schemes arising out of the above studies.
The Sindh Government unlike WAPDA has no organization to supervise work of consultants. A committee of experts from private sector can be appointed to work as supervisory body possibly on full time basis and if projects are under taken at one time, supervision may be assigned to the some aid agency, or agencies but consultant may, more profitably work with the Sindh Government to win the trust of people.
This is just a preliminary paper and a guide-line on water requirements of Riverain area of 2,112,000 acres, which had made rise of Amri, Kot Dijji and Mohenjo Daro, the Early and Mature Indus Civilization, and subsequent dynastic periods possible, and until inception of the railway as a great highway. For the first seventy years since introduction of the Indus Flotilla in 1860 it suffered badly in terms of trade and dwindling of its ports, but its fish industry had survived. Since opening of Sukkur barrage it started losing ground and with the opening of Kotri barrage the whole industry dwindled. Since that date, cultivation in Riverain area started reducing and in years 1999-2002 sailabi cultivation was no more possible. Since Riverain area has historical rights to cultivate land in Rabi raise pasture and forests on rest of the area, it is responsibility of Government of Sindh to develop it to its past glory.
This preliminary study should be followed by detailed studies and planning of projects, before final preparation. A master plan needs to be prepared after study of recurrent environmental changes and their impact. The process should include rehabilitation of cultivators, fishermen, foresters and traders and settlement of villagers.
The author does not claim that this is the final report on the subject. It is just a guide line and only points out the problems.
Author would like to thanks ‘Servants of Sindh Society’ for undertaking publication of his booklet and also ‘Sindh Education Trust’ for taking lead in printing it from its own funds. Special thanks are due to Mr. Muhammad Ibrahim Joyo, my dear friend since the past six decades, for undertaking responsibility of supervision of the publication, proofreading and many useful suggestions to make it press worthy. Thanks are also due to Mr. Siraj Memon to extend help specially financially in this work.
Author also takes full responsibility of various statements in the booklet, some of which may not carry due weight with some people, who have the same right to express their views, as author has.
M.H. Panhwar
54-D, Block-9, Clifton,
Karachi-75600.
May 8, 2002.
Chapter NO. 01
The neglected riverain area of Sindh: The present situation, and suggestions for its development.
The Riverain Area.
The Riverain Area in Sindh consists of approximately 2,112,000 acres or 855,100 hectares, lying on both the sides of the main stream of the river Indus, within the two flood protective embankments. These embankments or levees had been constructed over a century from 1860, to 1960, and the river was virtually trapped within these embankments approximately ten miles apart, protecting roads, railways, towns, villages and above all the agricultural crops out-side them, from annual floods of the river. The pre-barrage inundation canals could also be given permanent mouths to ensure water supply according to levels in the river. The river having westerly tendency is in general now closer to the right (west) bank, rather than to left (east) bank. The levees or embankments are 6-8 kilometers form the main river channel, which is 1-3 kilometers, wide at most places.
The main active channel of the river, Dhoros (its abandoned channels) and sand and mud flats in general occupy about 29% of the riverain area or approximately 612,000 acres as per aerial photographs. Some of the Dhoros get silted up year after year, opening up fresh arable plots for agriculture. The rest of the area of 1,500,000 or 1.5 million acres is slightly undulating with generally the higher levels along the embankments and slopping towards the Wahurs, Dhoros and the main channels in the center. Wahur is abandoned channel usually connected to main channel at some point, but Dhoros are not, though they too are abandoned channels. However this is not a hard and fast rule, as wind and water erosions and depositions have caused good many mounds between embankments and the abandoned river channels. Of the 1.5 million acres, approximately 1,000,000 acres are agricultural land; 450,000 acres are forest land and the rest 50,000 acres over villages, graveyards and unculturable waste lands. These figures can vary by 5% to -5% due to recurrent changes and more or less annual flooding of riverain areas yearly, but total area within embankments naturally remains the same.
This land was flooded annually during the inundation season to various degrees and depths and the whole land profile got over-topped or inundated, under going a process of erosion and accretion of new banks, until the river receded to its active-bed. Water absorbed in the ground during floods, gradually seeps back into the main channel and Dhoros after inundation. This alternating charging and re-charging of ground with water and its seeping-out has created highly permeable and fertile alluvium soils. Before commissioning of Tarbela Dam in 1973, floods visited every year and inundated almost the whole agriculture and forest area. More than 300,000 cusecs (cubic feet per second) discharge was common in almost 100% years. Heavy floods over 800,000 cusecs arrived in 1914, 1929, 1942, 1948, 1956, 1957, 1959, 1973, 1975, 1995, i.e., 11 times in 90 years. This overall trend is to continue and the planning of riverain area has to take into consideration this fact. A flood of 500,000 cusecs occurring three times in four years caused no damage. Floods of 300,000 cusecs occurred almost each of the rest years and were beneficial, but did not flood total agricultural and forest land. Heavy floods of 500,000 to 600,000 cusecs caused some damage, but heavy floods to 700,000 cusecs and above, caused 75-100% damage to housing, Kharif (summer) crops, government buildings, river port facilities, the stored grain and animals and caused some human casualties. However people were happy for ensuing better prospects, i.e., Rabi (winter) crops on preserved moisture (Bosi). In recent years if flood water exceeded 500,000 cusecs, there also was damage to tube-wells and housing, chocking of dug wells, damaging government buildings like schools and hospitals and above all causing dislocation of population and animals.
Frequency of peak floods at down stream of Sukkur barrage for the years 1907-1976.
This is given in the table below:
Table 1.1 frequency of peak flood 1907-1976.
Flood exceeding causes Frequency or recurrence times in 100 years.
300,000 98%
400,000 86%
500,000 77%
600,000 55%
700,000 28%
800,000 13.3%
(Source: WAPDA, 1976, Development of Riverain Area Part-I)
These are the figures prior to dams constructed in India, as well as Mangla, Tarbela and Chashma in Pakistan. Presently even the usual; 300,000 cusecs discharge is not possible in most of the years. Figures for year 1977-2000 are not available to the author. The major advantages accruing from annual flooding are:
The soils in the area are generally highly permeable; they have higher horizontal permeability than the vertical one, a factor advantageous for recharging from the river, when in flood. Thus, helpfully, the soils in the area remain salt free.
Horizontal permeability of the soils is disadvantageous too, in a much as the soils lose water to the river much faster. This disadvantage comes in the way of Sailabi cultivation. If the river recedes in August or early September soils lose moisture before sowing of crops in late October. Before commissioning of Tarbela, floods receded at the end of September and moisture was available for sowing crops in October.
Except in rare cases, soil pH is 7.6 and higher at points, which are not flooded for years. Some of these high points are also having saline ground water underneath. Soils at these places have pH between 7.6 to 8.5 and usually over 8.0.
After recession of floods, water seeps out towards the Dhoros and the river bed gradually, over many months. Until onset of next floods therefore, with a little soil working, crops are raised regularly on the preserved moisture on this soil. This type of cultivation on preserved moisture is called “Sailabi” or “Bosi” and had been traditionally practiced in Sindh for over 5,500 years or since the archaeologically called “Amrian Times”. It consisted of complex water management from Wahur to Dhoro and to the diminutive Dhori; these are from-big-to-small size and originate from abandoned channels of the river Indus. Water enters Wahur from the main channel in the inundation season or even when water recedes. Dhoros or Dhroi are not connected to the main course or Wahur. Water is led from Wahur to Dhoro by cutting a small channel, which fills Dhoro to the level of Wahur at the point of cut. From Dhoro water is led to Dhori to fill it up. From Dhori water is led to small fields each 4 to 8 acres area having dish shape and below the level of water in the Dhori. At point of water entry Wahur has same level of water as in main river Channel. But at various points along its length it has higher level than adjoining point of the river as bed has slope of about 12.2 CMS per kilometer and level of water in the Wahur will remain the same as at the point of entry.
Though crop yields of Katcha lands, raised only on preserved moisture, are half of those in the irrigated Indus plains, but even without fertilizers, herbicides and pesticides, the yields double up if two irrigation doses are applied to Rabi crop from Wahur-Dhoro-Dhori, to meet deficiency of water during flowering and ripening of crops. Farmers knowing it have adopted the system for higher yields, wherever possible.
Water which seeps towards the river bed also has low salinity; for example the Indus waters have total soluble salts (TSS) contents of about 150 ppm (parts per million) during the inundation season in the months of July and August, but seepage water form the ground, as received at Kotri barrage in the month of May, prior to the on-coming inundation, has TSS of 250 to 500 ppm. This regenerated water in the river is utilized in the down-stream of barrages, namely Sukkur and Kotri, and adds greatly to the economy. The Kotri barrage depends solely on seepage or regenerated water of the river after the inundation season. The Sukkur barrage has historical rights on water of the Indus, including seepage between Kashmore to Sukkur by this process. The Kotri barrage does not have allocated rights under 1945 Sindh-Punjab Water Agreement, but seepage water from embankments thus supplied for the past 40 years has created its own historical rights too and this quantity has to be supplied without fail each year.
Dhoros remain filled with water to varying degrees and water is lifted from them for raising summer and winter crops Wahurs or recently abandoned channels are a few miles long and some times connected to the main channel. A Wahur nine miles long connected with the river at top end and not along its whole length will have water six feet (1.8 meters) higher than the nearby main channel at its tail end, if it has well developed natural embankments, due to slope of river bed, as well as the land, as discussed above. Thus Wahurs can be used for gravity irrigation at suitable points, and have been used as such through out in the past.
Dhoros serve as fish stock breeding and farming ponds on natural phytoplankton and zooplankton created by solar energy as the only source of fish feed in the riverain areas of Sindh. Before creation of “One Unit” in 1955, Sindh produced 80% fresh water fisheries of Pakistan due to fishing form river channels and lakes filled by canals, and fish was sold at one third price of mutton. The fishing industry in the river has historical rights and the dwindled industry has to be re-activated.
The main channel of the river is also able to support variety of fisheries and aquatic life and adds to economy of Sindh. The whole area of 2.112 million acres was highly productive supporting large population of fishermen, farmers, livestock grazers and boats-men. The availability of 40,000 boats on the Indus between Halla and the Arabian Sea in Thatta Sarkar in 1600 AD, as reported by Abul Fazal only shows the employment opportunities, the Indus had provided before commissioning of railways, between 1860 to 1900. There were live ports at every 6 to 10 miles and they buzzed with population and their activities.
When railways were built, no provision was made for settlement of boats-men and their supporting service men in irrigated areas. They were forced to accept life to tenant farmers and this hit them socially in Sindh’s hierarchy of caste system, putting them into unpleasant situation. The business community at the ports was shifted to newly built railway stations by establishment of Notified Area Committees and allotment of land to them. Sukkur barrage did not have shiplock and this stopped direct boat traffic from the Punjab and NWFP to Sindh.
Some fishermen had some centuries old historical rights of fishing. Those at Rohri had rights to catch hilsa (palla) around Khwaja Khizir Tomb. Sukkur barrage did not allow hilsa to cross it to Khwaja Khizir tomb on its upstream. The fishermen asked for rights below the barrage head-works near Sukkur. It took 30 years to settle the case and when it was settled, the faulty Fish Ladder at Kotri barrage did not function and they asked for fishing rights below Kotri barrage. Before it was settled, water started flowing below Kotri barrage for less than 50 days a year and flows now only for a week or two.
The main channel of the river between Guddu and Sukkur remained navigable for small boats almost throughout the year, and for nine months between Sukkur and Kotri until 1970s. In post Tarbela period, this industry has dwindled forcing fishermen and boatmen to become tenant farmers, as no allocation of land was made for these two categories of workers in Kotri and Guddu barrage land distribution. This results form wrong planning, and responsibility whereof lies on the governments of the day controlling railways, canals and barrages.
With construction of barrages human resources, capital investment and government attention moved away to barrage areas and development in riverain areas became sub-optimal.
The Indus River behaves as influent stream during the summer or the flood season, when water from its streams seeps into ground towards the flood protective embankments. During winter it behaves as effluent stream and water seeps out from the fields outside and within embankments to the river stream. Dhoros, Wahurs and Dhoris.
Soils of the riverain area are fertile and free of salinity and of excellent quality. Sediments brought by river Indus from year to year have also enriched soils with macro and micro-nutrients, but these soils lack organic matter as compared to irrigated soils. This is specially so after the failure of flood occurring year after year, causing almost desert like conditions, due to lack of vegetative cover. Now it is an area in “low input-low output trap”.
The entire riverain area was the most prosperous area in pre-barrages period but has been ruined economically in recent decades.
Indications by aerial photographs.
Aerial photographs were taken in 1953, 1967 and 1973. Comparison of land forms in the riverain area during the three periods show continuous changes in land forms on the surface. Satellite photographs can give recent pictures of land forms. These photographs show that in absence of water, salinity problems have increased heavily in the riverain areas.
Roads.
In the riverain area permanent roads may never be constructed even by Cooperatives or sugar mills or local authorities, as the total area is bound to be flooded twelve to thirteen times a century, destroying these roads.
Constraints to agriculture in riverain area.
Factors like high water losses in watercourses and fields due to high permeability, higher infiltration rates, and higher horizontal than vertical permeability (though vertical permeability is also much higher than in the Indus plains), have caused low irrigation efficiency and extra water allowance has to be made for it. Other constraints are: lack of infrastructures, no roads, no telephones, no telegraphs and no markets.
The present position of inundation water.
Ever since construction of the flood protective embankments, the whole of riverain tract used to get flooded, year after year, during each inundation season, from June to October. The people were conditioned to temporarily move away from the area during the period. But after indo-Pakistan Water Treaty of 1959, India’s diverting waters for the irrigation purpose, and within Pakistan construction of link-canals in the Punjab and Mangla and Tarbela dams, the situation changed. Inundation water was reduced and riverain areas in Sindh no longer were flooded fully as before. Originally annual peak discharge of more than 300,000 cusecs of water in almost 98% years and more than 400,000 cusecs in 86% years, had ensured that the riverain area got nearly full flooded, and on preserved moisture good winter (Rabi) crops were raised annually, and luxurious pasture developed in rest of the area as grasses tapped shallow ground water, but now it is reduced to probability of once in every ten years or so, resulting into poverty, migration, unemployment, famine conditions, diseases and deaths. Poverty has led to infestation of area with dacoits, and poor riverain people are neither interested nor in a position to assist in eradicating them at their cost. Even if they want to, the government protection to them against criminals and dacoits is lacking.
Population.
The total population of the riverain area according to 1972 census was 750,000 people. Now, however, it is twice this figure, inspite of desertification caused by lack of food and the resultant migration. The concentration of population is in areas having tube-wells and forests. Recent Banana Bunchy Top Viral disease has resumed into abandoning of banana plantation in riverain areas below Moro to Ketibunder, and this has changed the population patterns in the whole area. The people have migrated away. The riverain areas if fully irrigated can support a population of three million people, in various trades, namely farming, fishing, transport and marketing, animal husbandry, forestry, etc. The constraints to development of the area are:
Poverty of the people.
Lack of capital to install tube-wells.
Poor infrastructures.
Brackish ground water in 50% of the riverain areas.
Desire to keep area backward and un-surveyed so that it does not come under preview of Land Reforms and big land owners occupying the area are made to surrender the land and nor pay agriculture income tax.
Uncertainty of the periodic low, medium and super floods, which disturbs and dislocates the regime and living patterns of the populace.
Tube-wells in the riverain area.
Prior to 1960 not a single tube-well existed in the riverain area, primarily on account of fear of losing it to the floods. After 1960s, however there has been continuous demand for the installation of new tube-wells.
The Dhoros are also exploited by way of pumping water from them for agriculture. Dhoros show virtually inexhaustible supplies of water if pumped in cautious and reasonable amounts. The Dhoros created recently by the river are 15-20 feet below the surrounding land and pumping from them induces seepage from adjoining lands towards them. They have proved to be much more economical than tube-wells, not only on account of low capital cost, due to elimination of under ground tube-well elements, but also due to less draw-down (drop in water level) at the pumping point or less suction or pumping head and thus creating economy on power for pumping. For the purpose of ground water development, Dhoros are a source of ground water, as they capture seepage water from adjoining areas.
Presently, there is no alternative, but to install tube-wells in this area to rehabilitate agriculture pasture and forest lands. The operation, maintenance and economy of tube-wells, is totally different from what it is in the irrigated areas, where tube-wells supplement the canal irrigation for the purpose of raising and promoting value added crops specially fruits, nuts or pomology and olericulture, which need more water than allocated quota during certain periods of the year, for optimum yields. Thus they play a special role in boosting the economy of already existing crops in irrigated areas. In the riverain areas, the tube-well installation and operation would immediately raise the question of most economical application of water to the crops. This factor alone would lead to new thinking, new analysis and new institutions for the support of the success of this experiment of raising crops on tube-well water alone. Due to the highest cost of irrigation water, the cropping pattern in the riverain area has to be totally different from that in the irrigated area. Farmers, extension workers, researchers and planners have to work to that end. If in every ten years, there is going to be flood of more than 500,000 cusecs in August, crops which tolerate flooding have to be investigated and introduced as summer crop, and there are not many such crops.
Agriculture land.
Of the 1.0 million acres of agriculture land approximately 0.45 million acres is privately owned called Kabuli and the balance 0.55 million or 550,000 acres is Nakabuli or State land. This land if disposed in pieces has to go to the people having Muhag or border rights of first refusal, if their holdings are less than 16 acres, although Land Reforms do not apply to riverain areas and these have now been declared illegal by Shariat Court.
Existing agriculture.
Traditional agriculture in the riverain area is based on Sailabi cultivation i.e., cultivation on preserved moisture for crops like wheat, oil seeds, winter vegetables, and melons, which all are winter crops. Kharif (summer) cultivated is carried out only on tube-well water is led from the main stream or Dhoros to low lying flat lands. Tube-well irrigation s limited mostly to sugarcane but some time cotton, sorghum, fodder, summer vegetables and summer oils are also raised. Use of tube-well water for raising mainly sugar-cane shows the general trend in use of pumped water for value added crops. It is encouraging that the future trend would mainly be to grow value-added crops, rather than conventional cereal culture or fodders which are un-economical to grow on tube-wells or lift pumps from Dhoros and are marginal on canal water even in irrigated areas. At present winter crops grown in the riverain area are winter vegetables, fodder, wheat, oil seeds, pulses and root crops specially onions, carrots and sweet potatoes. Melons and water-melons also form important non-tree fruit crops. Sugar cane where ever grown is the annual crop.
Forest land.
There are about 450,000 acres of government forestland in the riverain tract. These were supported by annual floods of the river Indus. The forest species establish themselves by natural selection, adopting themselves to the annual flooding for three to four months and depending on under-surface preserved moisture within the root zone for another three to four months due to their shallow tap roots system and for survival during the next four to five months, on the deep tap-root-system. In case of horticultural plants it is well known that taproots keep trees alive during the drought, but the fruit yields are either reduced considerably or fruit crop failure is common occurrence. It is probably the same phenomenon that the forest trees growth in Sindh dwindles during the “Off flood” years and recovery occurs during the “On flood” years with poor yields. Some forests of Sindh are known to have died of reduced to a mere xerophytes type growth, especially where flood water has not reached for some years. A good example is the lush green “Hilaya forest” near Kinjhar Lake, which perished due to lack of water. The common belief is that the forests need no regular irrigation water, but under the present circumstances without pump age from ground water sources, it is doubtful if they can survive or become economical. But whether such application of ground water to the present forest species would be economical, needs a thorough study and a further research. Whether any new forest species suiting to the present ecological conditions, need to be introduced for economic advantage or the species be continued to meet the running demand for supply of timber for mining, furniture, buildings and fuel, and this also needs studies.
Animal husbandry.
At one time riverain area was a paradise for animal husbandry in Sindh. The cattle owners from Kohistan, Thar and as far south as Kutch moved their herds to Sindh’s riverain areas, after supplies of natural grasses growing on rain water in those home areas were exhausted. Some 1.6 million acres of Nakabuli (Government) lands covered with grasses, shrubs and bushes in Kotri barrage were not the only pasture. Private lands also formed pasture lands and when these were exhausted, cattlemen moved to the Riverain forest areas, with or without permission of the authorities, but surely with connivance of the lower staff of forest department. Since early 60s natural pasture lands in Guddu and Kotri barrages totaling about 2.7 million acres of government land were converted into agriculture lands. Many cattlemen moved to the riverain areas, over-stocked them but these pastures too have dwindled totally due to lack of flood in the riverain areas since mid-70s, disastrously affecting animal husbandry of the nomadic population of the riverain areas and also of Thar and Kohistan, who also moved annually with their animals to the Kotri barrage pastures and riverain areas.
Fisheries.
The Dhoros and the riverbeds were vital to the economy of Sindh in providing fisheries resource. Once Dhoros are pumped for irrigation and water is lifted, it carries away with itself natural fish food, phytoplankton, and zooplankton, and fry-fish. The third could be prevented by suitable filters, but the first two will be pumped out along with the fish eggs and larvae. This loss would reduce the fish catch from already a low figure of a few mounds per acre of pond area. This industry thus has suffered equally as agriculture and forestry.
Tube-wells for reclamation of the riverain agriculture land and forests.
Impact of tube-wells.
Tube-wells can be installed for re-activating the area. They will draw water from underground by creating a cone of depression, which will induce ground water flow from surrounding lands towards tube-wells. Most of water would ultimately reach out form river channels and Dhoros.
WAPDA’s study (1976) shows that some 97% water drawn by tube-wells within one mile from the river bed will come form the river and 75% in case of tube-wells two miles from the river channel, clearly showing that regenerated water from the river available for Sukkur and Kotri barrages will reduce and only small quantity of ground water will come from water bearing strata under ground. To meet the deficiency, supply of water from storages would be essential to meet historical rights of Sukkur barrage as per 1945 Sindh Punjab Water Agreement and historical right created by forty years supplies to Kotri barrage form regenerated water. That riverain area has the right for cultivation of 100% Rabi crops in form of field crops pasture and forestry is a historical fact since Amrian Times i.e., for the past 5500 years. No attention is paid to this near-calamity state, as people affected are poor, tongue-tied and un-influential and can only think of and remain occupied in search of daily food.
Consequences of ground water development in riverain areas.
Ground water development will lower water table within the riverain area. When water table falls below root-zone of frost trees they would decline in health, if not die altogether.
Water table will normally fall by a few feet. If large number of tube-wells is installed for irrigating the area at 100% intensity, it will fall down by about five meters. This will dry up even the Dhoros, Dhoris, Wahurs and main stream, which support fish and also supply regenerated water to Kotri barrage. Forests will most probably die. Mining of water will also induce flow of gorund water from irrigated areas and deplete those areas of fresh ground water.
Occurrence of fresh ground water in riverain areas in Sindh.
The common belief is that, since the area has been flooded for over a century by the river waters, and year by year, and for the whole inundation season extending to many months each time, the fresh ground water of excellent quality is underlain in the whole riverain area and is also ever plentiful. Unfortunately this not true. It is almost a myth, as only in 50% of the area of total 2.112 million acres, ground water is fresh and in the rest of the area it is brackish and not only un-suitable for the human use, but also for irrigation and for animal husbandry purposes. Most of the time it is highly saline, but below Kotri barrage, salinity in most of the area is nearly twice as much as seawater i.e., 70,000 parts per million parts of water against 35,000 of sea water.
The following are observations on occurrence of ground water in riverain areas, starting from north near Kashmore to south near Keti Bunder.
Ground water near the town of Kashmore in the riverain area on the right bank is brackish and unsuitable for human use. Ground water is suitable for irrigation 15 miles south of Kashmore and further south on the right bank to five miles above Sukkur barrage head works.
Ground water on upstream of Sukkur barrage and above towns of Sukkur and Rohri is brackish on both banks within five miles.
The same is the case of ground water on the down stream side of the Sukkur barrage below Rohri and Sukkur, for about three miles.
Ground water is suitable from Guddu barrage head works on the left bank of the river Indus to about five miles upstream of Rohri.
From three miles below Sukkur barrage head works to the village Talti in Sehwan Taluka, district Dadu, on the right bank, ground water is suitable for irrigation.
Exactly similar to above, ground water on the left bank of the river is fresh, from three miles south of Rohri to the six miles north of Daulatpur, a settlement opposite to Talti.
From Talti to Kotri barrage head-works, on the right bank of the river, ground water is brackish and unsuitable for irrigation.
Although ground water in the riverain area from about six miles north of Daulatpur to six miles south of it on the left bank is brackish, but below this point to Miani forest (eleven miles north of Hyderabad) it is suitable for irrigation. Below Miani forest and up to Kotri barrage head-works, it is brackish.
Ground water from Kotri barrage head-works down stream to the sea is brackish, throughout the riverain area on both the right and left banks, as is the case in the whole Kotri barrage command.
Provision of water for the areas having saline ground water.
This is a question most difficult to resolve and needs not only administrative mechanism for carrying out the works, but also technical and economic feasibility for success. The failures of such a system at any stage, would cause disasters, specially because the brackish water areas are continuously lying from Talti to the sea on the right bank and from the Kotri barrage head-works to the sea on the right bank and from the Kotri barrage head-works to the sea on the right bank and from the Kotri barrage head-works to the sea on both the right and left banks. They form about 50% of the riverain area. As no flood water flows down-stream of Kotri in any year for more than fifty days and in some years for only a week or so, Dhoros and river channels dry up, leading to desertification. If surface water was available, this area would also be cultivated at-least from September to June. About 50% riverain area or 750,000 acres which have fresh gro0und water under-neath, would also need water for irrigation from tube-wells, but to recharge ground water, enough flood water is needed to flow through the river Indus bed in summer for assured number of days to recharge water bearing strata’s by as much as the water pumped out for irrigation in the previous season. Study of satellite imagery of riverain area shows the extent of area flooded, during the peak inundation season. The average for the last 20 years would be considered a fair amount of annual average flooding. Such area will not be brought under Kharif cultivation, but only after the floods would be put under Sailabi cultivation and one or two further irrigation dozes would be applied to the Sailabi land, to double the yields of most crops. All this needs extra water for 1.5 million acres of land in riverain area and this water needs to be calculated. Once tube-wells are installed, it would be difficult to stop farmers from pumping them in summer and rise Kharif crops.
Transportation of fresh water to the brackish water areas.
Transportation of ground water from fresh water area to brackish water area could be achieved in many ways, but these are not only costly but also difficult to handle technologically, and for which approval and considered decision of Government of Sindh will be needed. In brief it can be achieved by the following three different methods:
Surplus water from tube-wells in riverain area can be used in the adjoining canal command areas of Sukkur barrage, and extra water so saved in Sukkur barrage areas can be passed down-stream of the Sukkur barrage to Kotri barrage. There will be resistance to it form the farmers in the tapped irrigated area. It cannot be done in case of Guddu barrage as its canals are non-perennial, but it can be done in the case of Sukkur barrage. The disadvantage in this case is heavy evaporation losses, seepage in the river channel and cost of pumping, which will make the proposal un-economical.
An alternative to the above is that surplus ground water from Guddu and Sukkur barrages can be pumped into newly constructed channels which will run along the flood protective embankments to the next barrage, where it could be allowed to enter the barrage ponds, and from there it can be led into the new channels on down-stream side, along flood protective embankment. The flood protective embankment between New Jatoi and Daulatpur was made 85 feet wide at the top in 1974, to provide a channel in its center for soaking as well as taking water down stream. The disadvantage from it is the top-heavy cost of embankment channels besides the cost of pumping.
Ground water in the riverain area could be pumped in to the river channel for use on down-stream side. Disadvantage of this would be absorption of a part of water in the channel banks and evaporation, and, therefore, top-heavy cost of pumping per unit of water recharging at next barrage pond. Inspite of all these difficulties, the area of 750,000 acres cannot be abandoned and solution has to be found irrespective of cost considerations and technological difficulties as the area has historical rights.
Mining of water in Riverain areas.
In practice it is possible to over-pump the riverain area or mine water to be replenished during the next floods. It does have the disadvantage of high pumping cost, movement of water from irrigated area to the reverin area and movement of this water will cause lowering of water table in the irrigated areas. As a consequence, more water will be needed for irrigation, in those areas. There is also a danger of brackish water lying underneath fresh water, to rise and thereby turn the fresh water saline. There is saline water in vast irrigated areas in Larkana and upper Dadu districts out-side the river embankments. This water will gradually move towards the river and first turn the narrow ground water belt along the Dadu canal brackish and then get into riverain areas and turn them brackish too.
Riverain area between Kotri barrage and the sea.
This area is 87 miles (140 kilometers) long as the crow flies about 10 miles (16 kilometers) wide between embankments and had some 350,000 acres of land under forest and agriculture crops in 1980. It was most productive land in Sindh and had become the leading horticultural land in Pakistan, growing bananas and melons, which were mostly for export. Water shortage had hit the area, since 1980, but periodic release of water from Kotri Barrage filled the river channel and Dhoros and pumping was a resorted from them. By 1985 there was serious water shortage, but soon afterwards, Banana Bunchy Top Virus destroyed the banana plantations in the whole Thatta district in 1988 and 1989. The same was being carried by southwestern winds. By March 1990, the disease reached the vicinity of Hyderabad. Plantations out-side riverain areas in Thatta district had also been destroyed by the disease. Due to lack of water below Kotri, the melon industry too was destroyed.
Due to lack of water in the river flowing to the sea, tide water started entering the river. The high tide is about ten feet in height and with poor slopes of land of 2 to 3 inches a mile (00035 to 0.005%), water reaches upstream of Sujawal Bridge in the bed of the river. Ground water is brackish in the whole of Thatta district but fresh water in the river kept seeping in to the adjoining areas and diluted saline ground water, which had become potable for domestic and animal use for centuries. Since 1989, however, the situation has reversed and ground water has turned highly saline due to seepage of tide water to areas both within and out-side the flood protective embankments on both sides of the river. Salts have also come up the surface and surface salinity of soils has increased, killing the previous vegetation and making land unfit for cultivation or growing natural grasses. The fallow and waste lands, which once were grazing areas, turned into non-culturable waste lands. The people with animals there had to migrate away from all Talukas bordering the river in Thatta district. This migration caused dwindling of towns. A large town of Keti Bunder which had population of 25,000 souls, was left reduced to 5,000 in past 10 years showing the overall effect of migrations and dwindling economy.
The forests in the riverian area are no more and have disappeared. Fisheries industry in riverain area has almost disappeared too. Today the meager 5,000 people in Keti Bunder, the sea shore town, are not surviving due to inland trade, but due to fishing boats form Karachi, visiting it for provisions. The inland population has decreased not only due to absence of feed for the fish and fodder for the cattle, but due to scarcity of fresh water for humans and animals, which must now be brought from irrigated areas miles away to drink. How much overall population has migrated form the area is unknown due to lack of statistics. In general the area down stream of Kotri barrage headwork’s have turned into true desert and people have suffered more than in Thar and Kohistran, though this is never mentioned and given due notice.
Chapter NO. 02
Water requirement of crops in riverain area.
Assumptions.
Crop factor or water needed by plants is usually considered at 60-65% of pan-evaporation during the growing season.
Growing season in the Central Sindh for Kharif crops is 15th April to 30th September and for Rabi crops from 1st November to 15th March being 168 and 135 days respectively and total 303 days or say 300 days a year.
Water from tube-well can be pumped for 12 hours a day in summer and 10 hours a day in winter, only during the day light hours.
It is assumed that there is no down time involved in repairs etc., which would be carried out in October or 15th march to 15th April when water is not required. Any other down time would be taken care of, during off-pumping hours at night.
It is assumed that tube-well’s will be one cusec discharge and any water beyond the needs of a farmer will be sold to other farmers at rates, which will be competitive in the long run.
There is thinking that 50% of water at watercourse out-let seeps in the watercourse and the field. However for this study seepage loss has been assumed at 33% of the total water pumped and 66% utilized towards raising crop by using improved methods of water transport.
Since crop factor is 65% of pan-evaporation and seepage of water is 33% of tube-well discharge, water applied to crops would be about 100% of value of pan-evaporation.
Evapotranspiration from 15th April to 30th September in the Central Sindh is 59 inches or say 60 inches (1524 mm) and therefore water applied to Kharif crop including seepage and transpiration losses, would be 60 inches or 5 feet per acre in 168 days.
Evapotranspiration from 1st November to 15th March is 17.75 inches (444.5 mm). However farmer has to apply a dose of 4 inches of water every 2 weeks and the first dose of 6 inches for planting, in all total of 30 inches or 2.5 feet or 30 inches or 760mm of water in winter. In irrigated barrage areas water could be applied every three weeks as soils retain moisture for longer period, but in riverain areas soils are light with higher percentage of sand, and irrigation dose has to be applied every two weeks. Of 30 inches of water considerable portion will seep down, but there is no alternative, as cropping pattern will not permit precision land leveling as an economic operation. WAPDA has estimated that one cusec of water can irrigate 95 acres. This is erroneous as crop factor or crop water requirement is 60-65% of pan evaporation. Tube-wells cannot be operated for more than 10 hours a day. In sprinkler or drip-irrigation water application can match exact crop water requirement but not in flood irrigation. Drip and sprinkler irrigation systems are so costly that even horticultural crops cannot be raised on them under existing price structure of agriculture commodities.
We have suggested four doses, one every three weeks, considering that this would be practical dose regime on land not precisely leveled by laser equipment. For Sukkur barrage, planners suggested intensity of 27% Kharif and 54% Rabbi, and 19% fallow and 345 acres per cusec of water i.e., 93 acres Kharif and 186 acres Rabbi. In actual practice even by spreading water thinly, only 35 to 40% intensity was achieved in 40 years in Sukkur barrage area, where lands were better leveled. Our figure of 45 acres per cusec pumped for 10 hours makes it 108 acres if pumped for 24 hours, a figure close to that achieved in Sukkur barrage area on one cusec of water.
Water requirement is to be based on pan-evaporation and crop-factor.
The extra water will seep back into the ground, but it is assumed that it gets lost by evaporation from main streams, Wahurs, Dhoros and Dhoris. This dose of 4 inches can be reduced if land is precisely leveled by laser operated machine but in flood prone areas this type of leveling cannot be repeatest often and would be uneconomical.
Each tube-well in winter will be able to pump two acre feet a day, but only 0.833 acre feet in 10 hours a day and 112.5 acre feet in 135 days of the Rabi season.
It is assumed that very little land will be put under summer crops for want of historical water right of riverain area, though some area was under Kharif crops on wells and pond water in the past.
Total land in riverain area out-side the active river course, Wahurs, Dhoros and Dhoris is 1.5 million acres, of which 50,000 acres is occupied by village roads etc., and balance 1,450,000 acres is forest and agriculture land, of which 450,000 is forest land.
It is difficult and definitely uneconomical to raise forest tree on tube-well water and therefore it is assumed that on forest land also crops will be raised.
Since ground water in 50/5 riverain area is brackish, only on 725,000 acres crops will be raised by using tube-wells. The number of tube-wells needed would be 16,111 or say 16,000 for 50% of area in which ground water is fresh.
The 16,000 tube-wells will pump 112.5 x 16,000 acre feet of water or 1.8 MAF each year.
This is based on 100% intensity of 50% area under fresh ground water. If intensity is increased extra water will be pumped.
For rest of 50% area under brackish water, transportation losses will be 50% of water requirement or 0.9 MAF. Total water requirement shall be 2.7 MAF for brackish ground water area.
Total water requirement for the whole riverain area shall be 1.8+2.7 MAF or 4.5 MAF.
If forest department leases out the land, the policy should be to lease it out in 16 acres plots to number of small landless farmers, displaced from the riverain areas recently over a period of 20 years, and let the farmers install tube-wells accordingly. Leasing out land to big landholders and corporations will create social problems in area already infested with law and order problems.
Tube-wells will resolve only 50% problem as the remaining 50% area which has saline ground water, will need additional 2.7 million acre feet of surface water to irrigate it.
Water that seeps down the irrigated fields would find its way to Dhoros, Dhoris, Wahurs and river bed and would evaporate, but in the process would support fish fauna and should not be considered a loss. One advantage of this water could be that it would be rich in nutrients leached down form the fertilizers applied to the fields. One disadvantage would be that if herbicides are applied to soil, they may leach down and kill fish. Alternatives to herbicides are cheap but farmers need training. The availability of water in the Dhoros has historical rights.
Ground water is not un-exhaustible and has to be replenished each year from the river floods. It would require substantial quality of water flowing for more than a month to recharge ground water.
The riverain area had historical right of almost 100% flooding and thereby 100% intensity on water of the Indus. This has to be met.
This right should not be confused with water needed to stop intrusions of sea water in the Indus Delta, for which extra water is to be provided.
Extracting 1.8 MAF water will lower water table in fresh ground water area of 725,000 acres by about 8.275 feet, if proposity of soil is considered as 30%. There will also be seepage of water to the river channels and that may account for drop of another 7 feet. A total of 15 feet drop may be expected if riverain area is recharged every year and pumping be done only for Rabi crop only.
60% tube-wells will be on left bank and 40% on right bank in Guddu barrage area, but 70 and 30% respectively in Sukkur barrage area. Overall distribution can be 66.6% on left bank and 33% on right bank.
Behavior of regenerated water in autumn, winter and spring.
During autumn and early winter months, the discharge of the river at Guddu is less than the discharge at Sukkur, showing gain due to regenerated water between Guddu and Sukkur, but for the months of February to June the discharge at Guddu is more than the discharge at Sukkur, showing the absorption of water in the ground, allowing for the normal loss of evaporation from the river bed. The development of ground water is, therefore, going to affect the supplies of Sukkur and Kotri barrages and the latter could be the worst affected. Extra supplies of water are needed at Sukkur from February to June. Kotri barrage had minimum 3,000 cusecs regenerated water in March and April since its construction in 1955 down to the recent years. This historical use of water for the past 40 years cannot be ignored. It is affected because historical rights of Katcha (riverain) area are being considered and new tube-wells are being proposed for installation by WAPDA. Farmers have already installed more than 6000 tube-wells. Extra water is to be provided to replenish ground water so removed.
Size of a tube-well.
Larger the tube-well, more economical it is to own, operate and maintain. There will be quite a few farmers having sufficient land to go in for tube-wells of 3 cusecs or so, but most practical unit would be of one cusec. Larger the tube-well discharge, larger will be the area under its command and longer will the watercourses be. Larger the tube-well discharge, larger will its watercourses be and it would create conditions for excessive seepage losses from watercourses, as soils are sandy loam, having high permeability. Although bentonite is readily available at cheap rates for lining watercourses, to avoid seepage, but its economics need to be worked out. Polyester and plastic sheets are other items for lining, but exposed to sun’s infra red rays, they will crack fast. Special sheets resisting infra red rays have life of five years, but are un-economical under our price structure.
Protection of tube-wells during floods.
The tube-well structures of what-ever type i.e., centrifugal pumps into the pit, suction pumps on the ground surface, self-priming pumps on the surface, ditch pumps with vertical shaft turbine and submersible pumps or submersible motor pumps, all have to be protected from floods. The structures have also to be so designed and constructed that they are not of any cause of concern during the floods, with regard to erosion, deposition of silt in the pit, or around the pump house and inducing new channels or causing changes in the course of existing riverain channels. They are also to be such that they themselves are not damaged.
Organization for installation and maintenance of tube-wells.
The efficiency of tube-well operation would depend primarily on creation of separate tube-well installation and repairing services in private sector. Such organizations have to be created specially for the needs of the riverain areas and they have to specialize to meet special local needs. They have also to be headquartered in nearby cities to be available at short notice. Present drilling concerns are small organizations, previously installing hand pumps. They lack equipment for tube-well drilling and installation and do nothave know-how. Due to shortage of water in 2000-2002, a large number of tube-wells were installed by these parties and almost 80%
