Accumulating salinity destroying irrigated Agriculture in Indus basin for lack of drainage

Drainage and flood control are vital parts of irrigated agriculture as they relate to moisture control of crops in the field. Canal irrigation system is incomplete without its integral drainage system to evacuate excessive moisture and injurious salts from the root zone area of crops out of irrigated area to maintain salt and water balance, withhold water table depth, and control salinity. The obsolete, 150 years old, seeping and highly wasteful canal irrigation system in the Indus basin is unique, in the sense that it has no drainage system to maintain salt and water balance, control water table and evacuate the injurious salts out of the root zone area of crops, so that lands are kept healthy and productive. On the contrary the saline drainage effluent is retained in the ground and excessively used for irrigation by pumping about 45 to 50 maf of saline drainage effluent through one million small tube wells. 

The “seepage losses and the system losses” from the obsolete canal irrigation system is about 50 maf of water out of 105 maf diverted in the canal system.

Drainage is a vital and integral component of irrigated agriculture to evacuate injurious salts out of the area but is surprisingly missing and ignored. The result is that more than 60% of the irrigated lands in the Indus basin suffer due to accumulating salinity, sodicity and water logging to various degrees. It ranges from slight, moderate to sever salinity, sodicity and water logging.

Former President FM Mohammad Ayub Khan declared salinity and water logging as enemy No:1 of Pakistan. WAPDA made two futile attempts to provide drainage of irrigated lands by conceiving wrong projects of “tube wells based SCARPs and NDP”.  WAPDA wasted Rs 750 billion and a period of more than 20 years on two wrongly planned projects but badly failed to remove salinity, sodicity and water logging from the Indus basin. The irrigation system is now left to its catastrophic fate. Government took no notice of these mega failures, leaving irrigation system without drainage system subjecting lands to destruction by salinity.

In SCARPs and NDP both, WAPDA provided about 40,000 deep and large tube wells to pump the groundwater that was actually the saline drainage effluent accumulated for the past more than 100 years. A tube well with vertical flow in circulation is not a drainage infrastructure, as it has no horizontal component to evacuate salinity and maintain salt and water balance in root zone of crops and control water table.

WAPDA had no drainage idea how to physically evacuate injurious salts out of the area, control water table and maintain salt and water balance to keep soil healthy for maximum agricultural production. The Ministry of Water and Power, and WAPDA failed to meet these basic and vital requirements of drainage of land to safeguard the root zone area of crops. No agronomist from the PARC and no one from Planning Commission pointed it out the right method of drainage while approving the projects. The Provinces too failed except NWFP, where I planned sub-surface tile drainage for Mardan SCARP as I was the Consultant and Project Director. The project is functioning excellently for the last about 35 years.

WAPDA wrongly conceived that tube wells pumping would remove salinity, maintain salt and water balance, and control water table. Tube well lower the water table, and provide extra water that extra water is saline drainage effluent if used for irrigation. Tube well cannot achieve the objectives of drainage. Salty drainage effluent would remain in circulation by tube wells. WAPDA failed to conceive that extra groundwater is in fact the “injurious, saline drainage effluent” as accumulated, and is meant for physical evacuation out of the area.

 Instead of this, WAPDA put the injurious “groundwater saline drainage effluent” in circulation between the top soil and the groundwater drainage effluent for irrigation use, The saline water cycle circulates through the root zone area of crops that badly affects agricultural production invisibly and gradually. The resultant saline water circulation is concentrating, and increasing salinity in the top soil continuously as well as in the root zone of crops. WAPDA failed to conceive to maintain salt and water balance, fixing water table depth and remove injurious salts out of the area from the Indus basin.

After embracing failure, WAPDA abandoned SCARPs and replaced it by NDP costing Rs 500 billion. There was no change of concept between the SCARPs and NDP. Both the wrongly conceived drainage projects have failed and were abandoned without enquiring the reasons of failure.

The result is that the world’s largest contiguous canal irrigation system in the Indus basin is without its integral component of drainage system.

Wrong planning shows that no one in the concerned professional organizations knew the accurate technical definitions of “Drainage’, Leaching. “Irrigation”, and “Water Management”. If they knew the correct definitions, they would not have repeatedly planned and executed wrongly conceived SCARPs and NDP. WAPDA twice committed blunder. Later on, WAPDA simply abandoned and forgot the idea to provide the missing and vital drainage system. WAPDA probably could not conceive the right type of project planning.

After knowing the water coming out the SCARPs tube wells, the farmers of the Indus basin came to know and learnt that groundwater is easily available beneath their lands. As such, the small farmers during the past 30 years have started installing small and shallow tube wells.

The result is that there are about one million small tube wells that indiscriminately pump more than 50 maf of the “saline and saline-sodic groundwater drainage effluent” to irrigate their lands. The result of the miss-use of the saline effluent as groundwater is that their lands are gradually and invisibly getting more and more saline each year as more than 250 million tons of injurious salts are added to soil each year.

It is established  that if this dangerous trend continues it is feared that most of the Indus basin would become saline, saline-sodic and water logged with in about another 30 years.

It is surprising that surface and sub-surface tile drainage is very common in irrigated areas throughout the world. It is an established and well recognized drainage system practiced the world over. WAPDA failed to adopt this system. It shows WAPDA is unaware of the technical definitions of irrigation, drainage, leaching and water management while planning such mega projects. Why these definitions were not in the knowledge of WAPDA is surprising and is questionable?

For the information of WAPDA, I give the technical definitions of drainage, leaching, and irrigation. This will guide them. WAPDA must plan and design mega irrigated agriculture, and drainage projects in the light of their technical definitions. WAPDA is unaware of the capacity-inflow ratio while selecting dam sites.

Technical definition of drainage

“Drainage is the essential part of irrigation work, collecting the water that leached the salts out of soil and evacuating it out side the area, as well as separating the “reclaimed layer” from the sub-soil to avoid raising the water table with the resultant retrogression”.

WAPDA did not plan SCARPs and NDP according to the above definition of drainage. Therefore, both projects costing Rs 750 billion failed.

“Sub-surface tile drainage prevents a rise in water table, keeping the later at a depth that will not harm root development of crops and maintain salt and water balance”

In this system, even the “return flow” or drainage effluent after the leaching of land when salts are evacuated from the top to the root zone soil, would be useable for irrigated agriculture.

SCARPs and NDP were not designed to produce infrastructures as per the definition of drainage and leaching. The definitions clearly show to provide surface and sub-surface tile drainage to evacuate the leached injurious salts out of the area, maintain salt and water balance, control salinity and water logging, and keep water table at the desired depth.

Definition of Leaching

“Leaching is the process of dissolving and transporting soluble salts by down ward movement of water through the soil”

Definition of Irrigation

“It is designed to include irrigation, drainage and flood control all of which relate to the moisture control of crops in the field”

In view of the above definitions, SCARPs and NDP were criminal blunders that wasted Rs 750 billion, 20 years of time and cheated the nation twice and then abandoned it so that we silently lose irrigated lands in the Indus basin as saline wastelands and face famine, as we are now facing load shedding. Indus basin is the food basket of Pakistan. Its lands must be saved by tile drainage.

The basic and vital inputs of irrigated agriculture are healthy land, and timely water. We cry for water but ignore quality of land, and its chronic and serious problems. The question is if we lose land due to salinity, sodicity and water logging then what would be the use of water, of building of dams, barrages and irrigation systems? This is a very serious matter but no body pays attention to set lands healthy by providing surface and sub-surface tile drainage. The result in the near future would be like that of load shedding but food shedding is not possible. Sever famine will grip the country. It is surprising that PARC and the Ministry of agriculture is silent spectator though drainage of land, and irrigation of land are vital inputs of agriculture. They must point out their basic needs and instruct the water resources engineers to provide them infrastructure as is needed for healthy crop growth.

There is no quick solution for solving the issues of land, energy, floods and water to produce food to feed the rapidly growing population that would be 35 crores by the year 2040. We must foresee and plan 100 years ahead.

I was Consultant for Mardan and Swabi SCARPs. I conceived, planned and prepared feasibility reports for surface and sub-surface tile drainage. The project was successfully implemented. It is working excellently for the past 30 years. WAPDA has not learnt lesson out of it, as WAPDA is no longer a skilled and professionalize organization as it was planned.

 Further proof of this is that WAPDA once abandoned the Kachi Canal alignment from Mithan Kot for Baluchistan when half completed. The alignment was then shifted on the upstream to Taunsa barrage.

 Similarly, WAPDA turned Kalabagh Dam controversial as WAPDA gave tailored TOR to the Kalabagh Project Consultants that proved the project infeasible. WAPDA held Kalabagh in status quo for 36 years. WAPDA had no idea of the capacity-inflow ratio while selecting dam site.

 WAPDA ignored the construction of unique, multipurpose Katzarah Dam on the Indus and the multipurpose dam at Guroh Dop on Panjkora River the main tributary of Swat River discovered by me in 1962. WAPDA contributed nothing after 1974. Like IRSA, WAPDA’s head quarter must be shifted to Islamabad or it should be wounded up and replaced by the Indus Valley Authority for building dams and barrages on the Indus.