PAKISTAN National Institute of Oceanography and National Science Foundation has established that salt water intrusion into the plains of lower Sindh is directly related to the decrease of flow in River Indus. Salt-water intrusion has been witnessed inland up to 100 km north of the sea.
Seawater has rendered fertile agricultural lands useless, resulting in loss of jobs and economic devastation. Hundreds of villages in the Badin and Thatta districts have been deserted and people have been forced to migrate to some other areas.
Results of a survey conducted by the government of Sindh indicated that over1.3 million acres land has been eroded or lost to the sea within Thatta and Badin districts, dislocating a quarter million people and inflicting financial losses over $2 billion.
According to official figures, 170,267 acres had so far been lost in Kharo Chhan taluka, 115,474 acres in Keti Bundar, 424,419 acres in Jati, 22,898 acres in Mirpur Sakro, 512,865 acres in Shah Bundar and 32,060 acres in Ghorabari. Out of 1.3 million acres inundated by sea, 1,216,000 acres belonged to the government and 59,000 acres to farmers whereas 89,000 acres were under cultivation. The local people and NGOs estimate the loss of 2.2 million acres of fertile land.
Due to reduced water flows to lower Indus basin, lakes and wetlands are also loosing their inflow and slowly becoming polluted. And smaller ones are even drying out and any life in them dying. Some of these lakes and wetlands are showing signs of being polluted. Manchar, the largest lake in Sindh, has become a dumping ground for discharge from salinity outfalls. Its ecosystem has thus begun to be destroyed although it is the source of water and irrigation.
The salinity level in Manchar lake is causing public health problems, reduction in crop production and the land degradation. Millions of people have been affected and thousands of Manchar fishermen have migrated to other areas.
The quantity of water outflow to sea has been progressively reduced, particularly after the construction of barrages, dams and link canals under the Indus Water Treaty, 1960. The actual outflow to sea at the time of independence was about 80 million-acre feet of water (MAF), which has now reduced to 0.78 MAF in 2000-01.
Studies have shown that Indus River used to throw 400 million tons of silt into the sea every year, which has now been reduced to just about 10 million tons a year. The flow downstream the Kotri for last ten years is given in Table No-01. The duration of the flow has also reduced to less than two months and that also only in high flood years.
This gradual depletion in flow of sweet river water and rich silt into sea has led to sea water intrusion leading to hyper-saline condition in the coastal area that literally kills life in all forms, livestock and vegetation on land and fish and other edible marine varieties and the rich mangroves forest in the sea.
Before the barrages, agriculture was flourishing in Keti Bandar and Kharo Chann. There used to be a rare red rice, millet, gram and vegetables cultivation in both coastal districts of Badin and Thatta. But a few years after the Kotri barrage was built, landowners who had up to 500 acres of land became so poor that economical conditions forced them to work in the cities.
Keti Bandar has thrice changed its location. Its previous locations are submerged under sea water. Presently it occupies much lesser geographical area than it used to. Population of Keti Bandar is also declining, presently about 3,000 people are living in poor conditions at Keti Bandar. People of Keti Bandar have not only lost their properties, but graveyards also, where their near and dear ones were buried. Sea is intruding fast and is at a distance of 36 km from the coast of district Thatta wheras previously it used to be 100 km away.
Out of 44 Dehs in Keti Bandar 40 Dehs have submerged under water, now only for Dehs i.e. Tapo Babio, Tharo, Mir and Mor Jhadio are intact. Because of extended zero flow periods caused by diversion of water following construction of the Kotri barrage, the river bed below Kotri has become severely braided and the channel can become blocked by sand bars.
The active Indus delta has been reduced to about one tenth of its original size largely as a result of the construction of river flood bunds confining the river. The freshwater and sediment discharge during the flood period is restricted to the active delta.
The increase in salinity during the low flow periods has reduced the suitability of the delta for the cultivation of red rice, production of exotic fruit and raising of livestock.
There has also been severe damage to livestock. Saltwater intrusion caused a dramatic decline in livestock numbers in all the sub-divisions of Thatta district, bringing about depletion and erosion of ranges, shortages of fodder, pasture and potable water. Throat swelling due to drinking brackish water is a common complaint witnessed in the affected areas. Lack of clean drinking water in the area has contributed to widespread water borne diseases like diarrhoea .
Affected population comprises mostly of rural areas with 90 per cent of the total population concentrated in rural localities. This has resulted in mass migration of inhabitants to cities especially to Karachi.
The area remains enslaved to poverty and illiteracy. High birth rates, low household incomes and small housing units all keep coastal community in a web of deprivation. Poverty in the areas touches 70 per cent. It is a mainly agrarian society where most of working force is involved in occupations in the primary sector that is agriculture, forestry, fishing and animal husbandry.
The 20 MAF water will flow downstream the Kotri during the current Kharif season as a welcome news. Unfortunately, Wapda officials are trying to give the impression that the flow of freshwater into the sea is wastage of water, knowing well that it is a mandatory for keeping the coastal environment alive.
The people who regard floodwater escapage to sea as waste and wish to store it will have to understand the nature’s cycle before reaching a conclusion. Unfortunately, the issue of fresh water release below Kotri barrage for saving life of coastal community has always been tackled politically or administratively, rather than humanitarianly.
On the international level, coastal communities has employed especial measures for counteracting saltwater intrusion. The Delaware River Basin Commission, for example, protects Philadelphia’s freshwater intake on the river, as well as New Jersey aquifers recharged by the river, from excessive salinity by storing water in reservoirs during the wet season and releasing it during droughts, forcing the saltwater back toward the sea.
Other communities have protected coastal aquifers by erecting underground barriers and by maintaining freshwater pressure through the use of impoundments and injection wells.
Until adequate water is released downstream of Kotri, sea water intrusion combined with raised level of Arabian sea due to climatic changes will make Thatta, Badin, and southern parts of Hyderabad district waterlogged marshlands. Study carried out by the IUCN, have suggested that a discharge of 35 MAF is required at the delta to prevent further damage to deltaic area.
Under the provisions of the Water Accord, 1991 a quantity of 10 MAF has been provisionally earmarked for outflow downstream Kotri pending further studies to be undertaken to establish the needs of minimum escapages down stream Kotri. Ever since the 1991 Water Accord, Sindh has never received its fair share of Indus water, the study for outflow to the sea has not been performed which is obviously a malafide act as there was no financial liability on the government, and the water outflow to sea has never been as allocated.
A major proportion of floodwater flows towards sea during the month of August, a period when sea produces extremely high tides, thus chances of backlash of seawater are very prominent. Floodwater during August acts as a natural barrier for preventing the backlash of sea water. Therefore all attempts of blocking the flood water during high flood season will be practically the same as to altering nature’s practice thus inviting sea water to intrude further coastal areas.
The harsh reality is that the any new large dam on Indus will very adversely affect Sindh as she will be the worst sufferer as a result of destruction of its agricultural economy and irreversible devastation of its delicately balanced coastal ecosystem, which would deprive lingering coastal population of its livelihood and render large areas in its coastal belt uninhabitable within a few years.
The alternatives to current water crises are efficient water delivery system and on-farm conservation of water. We must move towards sustainable and indigenous renewable development and restoration of the rich integrity of the natural resources of Pakistan.
