In spite of such huge resources available for about 22 million hectares of cultivated land, Pakistan has not been able to achieve self-sufficiency even in most of the food items.
Our average crop yields are much below than the yields of most of the developed and the developing countries. Disputes on the share of regulated rivers water by the provinces, on the barrages, canal commands, distributaries and share holders on water courses are quite common.
This is all due to unfair distribution of available water. The following presents the mismanagement scenario of precious water resources at the national as well as the provincial level.
Some areas do get more water supply than their due share and misuse it through over irrigation resulting in low productivity and others do not get even the due share and the crop yields decrease due to inadequate irrigations.
Following table indicates the cropped area and area irrigated by different sources (In Million Hectares)
Out of 21.85 million hectares of the cropped area 18.22 million hectares is irrigated which is more than 83 per cent. The canal water is the major source of irrigation for 80 per cent of the cropped area. Sindh province is mainly dependent on canal water as ground water in 90 per cent of the area is highly saline and unfit for irrigation purpose.
Canal water being the main source of irrigation is, therefore, to be managed properly for enhancing agricultural productivity and sustainability of crop yields.
Water requirements of different crops termed as ” delta” is expressed in acre inches or hectare meters which is a vague term when consumptive use of water by crops is considered on the basis of soil, plant and water relationship. Actual requirement of water for a certain crop depends on the type of soil. However, there is no proper measurement of water in irrigation applications by farmers and it is usually applied as per availability from the canals.
Canal irrigation system is supply-based and not demand-based. Canal water is supplied by the irrigation authorities as per availability in the river system and does not coincide with crops at various stages.
Farmers cannot irrigate crops at stress condition due to rotation on the distributaries and minors which adversely affects the yields. On the other hand, whenever water is available they over-irrigate for sustaining higher yields, However, the same is never achieved through over-irrigation which causes the dual menace of water-logging and salinity. The positive impact of other inputs like seeds, chemical fertilizers, cultural practices, and pesticides is directly related to proper use of water.
The unjust distribution of water from the river system on the basis of geographical area of certain unit, province or canal command without due consideration to agro-ecological conditions and crop zones is a sort of massive mismanagement of water. Detailed scientific studies are required for this important aspect of mismanagement for combating environmental degradation, and for the guidance for the end-users.
Our irrigation system is in dilapidated condition resulting in very high seepage losses. The main as well as branch canals, distibutaries and minors are poorly maintained resulting in water losses of more than 40 per cent as compared to the losses of 20 per cent from properly compacted and maintained earthen channels.
The irrigation network in the province consists of three barrages,14 main canals,109 branch canals,1446 distributaries/ minors and 43000 water courses. Withdrawal from three barrages, in the range of 36 to 44 maf, depending upon the climatic conditions and availability of water in Indus river system, is conveyed to the farms through this network. Out of 44 MAF, about 16.5 MAF may be available in Rabi (winter) and 27.5 maf during Kharif(summer).
After deducting about 55 per cent conveyance losses from canals, distributaries, minors and water courses due seepage, breaches and poor maintenance, hardly 20 maf become actually available for the crops . Even a layman can visualize the enormity of misuse in non-perennial canal command, paddy growing areas, during kharif when all areas in the upper reaches of the canals and distributaries are completely inundated showing a gloomy picture of wastage. Situations have been observed where tail enders do not get even water for drinking purpose, whereas farmers in upper reaches have to drain out the excess water from their paddy fields.
Almost all modules of water courses in non-perennials canal commands are tempered, drawing even in times more than the allocations and the requirements of crops. Tempering of modules is common although these are controlled to some extent and illegal withdrawals are not so high.
The direct outlet system(dos) from the main and branch canals has jeopardised the whole distribution system and canals which were supposed to supply proper water to the distributaries have been sieved rendering them unable to get their proper supply,
The system of direct outlets from main and branch canals accelerated at high pace after 1972 and the competent authorities sanctioned large number of direct outlets as bribe to their political supporters without any justification and technical reasons. Corruption of irrigation bureaucracy and greed of feudal farm owners have aggravated this situation. It has been proved through various studies that the big land owners having political backing are misusing more water and are the main cause of over all low productivity.
Absentee land lords whose lands are looked after by their managers known as “kamdars, are the worst destroyers of the irrigation system. They misuse their excess water without any positive results adding only to the degradation of soils through water-logging and salinity.
As it was proved through studies that major losses (35 to 45 per cent) occur through the water courses. Various projects for water course lining were implemented with financial assistance of the World Bank and other donor agencies from 1978,under which 7500 water courses were lined in Sindh upto 1996 with 15 to 30 per cent lined length in fresh and saline ground water areas respectively.
Since the civil works were carried out by the officials under the on-farm-water-management projects, the awareness for ownership could not be created among farmers. About 25 per cent water which was saved through this lining was usually wasted by farmers through over-irrigation.
Considering the importance of the water-saving, a mega project. “ national programme for improvement of water courses ” has been launched with the financial assistance of the federal government under which 29000 water courses will be lined in Sindh at a cost of Rs22 billion in four years.
As the water courses are joint property of the farmers/water users, the lining work will be carried out by the Water Course Association under the technical guidance of the project staff. However, the need for creating awareness in farmers for the proper utilization of saved water still remains there.
Yet another project, ‘ Sindh on-farm water management“ has been launched with the help of the World Bank under which 4000 water courses will lined along with improvement of 100 distributaries , 25 branch canals , social mobilization for forming 100 farmers organizations on distributaries /minors and precision land levelling of 40000 hectares through lazer land levelling equipment. There is a better component of social mobilization for awareness of farming community under this programme for the efficient use of irrigation water.
However, following measures are suggested for better water management and for enhancing the productivity:
* participation of end users/farmers is a must through farmers bodies for improving water management which is not possible through age-old bureaucratic set-ups.
* water distribution must be fair at all levels.
* conveyance system of water in canals, branch canals and distributaries must be improved for reducing water losses.
* water courses must be lined with participation of farmers while creating awareness among them for better maintenance and efficient use of water.
* irrigated lands must be precisely levelled through land levelling equipment.
* efficient systems like drip/trickle and ‘sprinkler’ must be introduced in water scarcity areas and full financial assistance be provided to farmers by the government.
* high delta crops like sugar cane be allowed only in climatically favourable areas where higher yields could be achieved and drainage of soils is possible at economical cost.
* value-added low delta crops might be introduced as alternative to the high delta crops like sugar beet in place of sugar cane to save water and reduce water logging and salinity.
* individual farmers in saline ground water areas must construct small farm water reservoirs of one to two acres for storing surplus water and using the same in critical stages of water requirement of the crops, and government should provide technical and financial assistance to farmers for the purpose.