LAHORE, April 7: The irrigation system of the Punjab, consisting of numerous barrages and canals, is in a precarious condition and prone to failure. It requires immediate and extensive repairs, estimated at Rs150 billion, to save it from further deterioration.

The warning was given by Asrarul Haq, an expert of the Punjab Irrigation department, on Wednesday. He was presenting a paper in the technical session of the second day of the 69th annual session of the Pakistan Engineering Congress at a hotel here.

The expert said that the irrigation system had progressively deteriorated because of aging, inadequate maintenance, over-stressing of the channels and structures and phenomenal increase in the use of canal banks by the human, animal and vehicular traffic.

Weak canal banks, eroded berms, channel cuts and breaches characterize the system's deterioration in addition to frequent sedimentation of distributaries and minors and dilapidated conditions of canal structures.

"Many hydraulic structures, which are 50 to 100 years old, have outlived their useful life and are suspitable to serious damage if not immediately attended to."

Failure of some major structures in the recent past caused stoppage of irrigation water to large areas with heavy losses. Recent surveys revealed that numerous important hydraulic structures, including barrages and canal headworks, were in a precarious state.

The collapse of two major structures in 1996, the outfall structure of Balloki-Sulemanki Link canal and regulator structure of Marala-Ravi Link canal had caused serious concern about the state of the health of the entire irrigation system.

Mr Asrar said that broad categories of damage and deficiencies in the irrigation structures and canals included design-related deficiencies, changes in operating conditions, serious retrogression downstream of barrages, deferred maintenance, aging process and hydraulic, structural and mechanical problems.

The system management also suffered a serious setback because of deterioration of the canal communication network and lack of adequate transport facilities.

As a result, communication blackout between the managers and operators severely hampered the management capability to respond effectively to the problems and emergencies.

The expert said that Pakistan had the distinction of the world's largest contiguous irrigation network whose present value is estimated around $300 to $500 billion and that of the Punjab about $200 to $300 billion.

The system serves as a lifeline for sustaining the present level of agriculture. The irrigated lands supply more than 90 per cent of the total agricultural production, which account for about 25 per cent of GDP and employ 50 per cent of the total labour force.

The lands supply most of the country's required food grains and raw materials for major domestic industries and exports. The length of main canals and distributaries exceed over 60,000 kilometres, which irrigate over 14 million hectares of cultivable commanded area through 100,000 outlets in 43 main canal systems in four provinces of Pakistan.

The expert said that over decades of canal system operation, the manifold increase in population and the sociological, cultural, agricultural and economic practices have changed radically. This has substantially modified the actual cropping patterns and intensities.

"As a consequence, the design considerations and capacities, which might have been relevant at the time of the system's construction, are no longer adequate to meet the present requirements.

"The annual average cropping intensity in the Punjab is estimated at 122 per cent against an average designed capacity of 63 per cent." Mr Asrar said that the recent studies conducted by the consultants on Lower Bari Doab Canal System concluded that the canals supply only 44 per cent of the net overall crop water requirements in Pakistan while ground water contributes 34 per cent of the requirements.

"This still leaves a deficit of 22 per cent of water in a well-developed canal command area, which is endowed with fresh ground water that the farmers can tap economically."

The expert said that all out efforts should be made both by the public and private sectors to meet the challenge and the enormous cost of the irrigation rehabilitation programme estimated to cost Rs100 to Rs150 billion. There was great need to conduct a comprehensive master planning study for providing investment.

An initial investment of Rs1 to Rs1.5 billion per annum should be made for emergency repairs of the irrigation network and Rs2 to Rs3 billion per annum for rehabilitation needs with limited up gradation in a phased manner and intensive investment of Rs4 to Rs6 billion per annum for up gradation and modernization of irrigation network to enable it to face the challenges of the 21st century, the expert said.