Kotri Barrage built in 1955 is downstream barrage on the Indus River, before it discharges into the Arabian Sea. There is about 178 miles of river reach from the barrage to the sea.
At present, Indus River discharges in the Arabian Sea at two points— Turshian and Khobar. Indus Delta region marks Sindh’s 300km long coast with Arabian Sea. Before the building of barrages, the coastal agriculture areas of Keti Bandar, Kharo-chan and Shah Bandar produced rice as the main crop for export. The sea-borne goods in transit to upper Sindh area used to be transported to river boats.
The socio-economy of these areas was very good and people were prosperous. The area was a major producer of milk and ghee (clarified butter) which was exported to cities as far as Bombay.
There used to be a rare red rice, millet, gram and vegetables cultivation in both the coastal districts of Badin and Thatta. Due to the drastic reduction of Indus discharge of freshwater and sediments after the construction of Kotri Barrage in 1958, coastal agriculture and the status as a viable sea-river port, both were lost.
Keti Bandar has changed thrice 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 declining and people live there in poor conditions.
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 Indus Water Treaty (IWT) signed by Pakistan and India in 1960, resulted in an altered distribution of flows in the river system.
Extensive infrastructure development took place that included link canals, barrages and reservoirs, to mitigate the allocation of waters from Beas, Sutlej and Ravi rivers to India. The actual outflow to sea at the time of independence was about 80 million-acre feet of water (maf), which now stands reduced to 0.78 maf in 2000-01. The duration of the flow has also reduced to less than two months and that too 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 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 mangroves forest in the sea.
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 the raising of livestock.
The salinity has reached to a level of 40 to 50 ppt (particles per thousand) compared to 15 to 20 ppt half a century ago.
Thatta, a predominantly agricultural district in Sindh, and situated where the Indus river flows into the Arabian Sea, has been worst affected. Out of total geographic area of 4.29 million acres, the sea has invaded about 1.2 million acres of fertile land and the adjoining areas. The effects are not just restricted to land inundation but mangrove forests. In an essential breeding ground, shrimps and freshwater fish species are disappearing fast.
According to World Commission on Dams (WCD), seawater is gradually increasing and causing irreversible salt deposition in the lands which have been rendered unsuitable for any agricultural activity. Particularly, areas of Kharochaan, Garho, Shahbunder, Keti Bandar, Golarchi, Seerani and Bhugra Memon are the worst hit. Local communities attribute this loss to diminishing river flows below Kotri since the construction of Kotri barrage and Mangla dam.
It is also reported that due to changing climatic patterns in coastal areas and continuous soil erosion by tides, remaining land resources are also being threatened. Another impact on groundwater resources is the pollution of the aquifers situated close to the Arabian Sea. Rising salt content of the groundwater has made it unsuitable for irrigation. Also salt depositions in the land have also affected yields and overall production.
Local villagers believe that the reduction of water supply to Indus delta has forced many peoples to migrate from one area to the other, mostly due to shortage of drinking water and increased salinity and water logging problems.
Under the provisions of the Water Accord, 1991, a quantity of 10 maf was provisionally earmarked for outflow downstream Kotri pending further studies to be undertaken to establish the needs of minimum escapages downstream Kotri.
The Sindh and Punjab have remained engaged in controversies for 15 years on the Terms of Reference (TOR) of the studies, and the communities suffered as the area kept degrading for want of fresh water escapages. The promised 10 maf water was never released during all these years except when the floods came.
Finally, three studies were carried out namely, study on Water Escapages below Kotri Barrage to check sea water intrusion (Study-I), study on Water Escapages Downstream of the Kotri Barrage to address environmental concerns (Study -II) and a third study on the environment concerns of all the four provinces.
Ignoring the apprehensions of experts two separate studies by different consultants were carried out to establish water requirement down stream Kotri( studies-I and II) with two interrelated and inseparable term of studies, which made the whole exercise suspicious.
Further, the federal government relates the issue to the third study, which has nothing to do with water requirement downstream Kotri, with Water Accord, 1991, in clear violation of the accord. In this context, government has recently published the review of studies on water escapages below Kotri barrage by International panel of experts (IPOE).
IPOE has recommended that a total volume of 25 maf in any five years period (an annual equivalent amount of five maf) be released in a concentrated way as flood flow (Kharif period), to be adjusted according to the ruling storage in the reservoirs and the volume discharged in the four previous years.
IPOE in para IV of executive summary says: “An escapage at Kotri Barrage of 5000 cfs throughout the year is considered to be required to check seawater intrusion, accommodate the needs for fisheries and environmental sustainability, and to maintain the river channel. The IPOE likes to stress that seawater intrusion only concerns problems related to surface water, because salinity in the aquifer is predominantly due to fossil water salinity from geological origin”.
The above finding comes as a surprise since the historical record and studies by IUCN, WCD, NIO and other agencies reveals that ground water salinity downstream Kotri has changed drastically after the commissioning of the barrage and reduction of flow downstream.
According to the experts working at the National Institute of Oceanography (NIO), “The substantial storm tides from southwest monsoon winds in summer inundate vast area of both the active and the abandoned deltaic plains with salt water. This area of lower deltaic plain is characterized by tidal creek and small over-bank plains that are lined with stunted mangroves on a sand/silt substrate”.
They add: “reduced freshwater from Indus has also increased seawater intrusion inland making the coastal land too saline for traditional agricultural crops e.g. red rice, sugar cane and banana. The rapid environmental degradation of the delta has its socio-economic impacts. These impacts are more pronounced on the coastal communities living within and close to the Indus Delta Mangrove Ecosystem”.
The major proportion of floodwater flows towards sea during the month of August, a period when sea produces extremely high tides, chances of backlash of seawater become very prominent. Floodwater during August acts as a natural barrier for preventing the backlash of seawater.
The constant flow of 5000 cfs throughout the year as suggested by IPOE is not sufficient to preventing the backlash of seawater during high tides. Therefore any attempt of blocking the floodwater during high flood season will be practically the same as to altering nature’s practice thus inviting seawater to intrude the coastal areas.
IPOE in para VII of executive summary says: ‘As far as the mangrove vegetation is concerned a certain flow and sediment supply will be required, together with control of camel grazing and fire wood cutting, and mangrove replanting. In order to spread the water over the flats a concentrated high flow would be needed during the Kharif season.’
‘ The amounts of fresh water as mentioned under item VI will be sufficient for a sustainable mangrove growth. It is considered to be of utmost importance to manage the mangroves in such a way that a sufficiently wide mangrove belt is being maintained in front of the coastline. The IPOE recommends that this be considered to be a national responsibility.’
It is not understandable how flow 5000 cfs through small channel will protect and rehabilitate forest area of about 0.16 million ha in inter-tidal part of the delta consisting of about 17 major creeks. This forest is in arid climate and completely dependent upon the freshwater discharges from the Indus River.
Studies by IUCN has recommended least 27 maf of the Indus outflow to the sea for stopping sea intrusion and for maintaining coastal ecology which is equal to flow of 0.3 million cusec for 45 three days is required. These figures appear more logical.
The coastal communities have long been dependent on the coastal mangrove forest to meet their demands of food, fodder, fuel wood, sea-salt, timber for their temporary hutments (jhuggi) and generation of income and for economic activities.
The mangrove forest and adjacent grasslands have been providing fodder and act as natural grazing areas for cattle of local community since past several hundred years. The cattle (buffaloes, cows) provide a source of milk for family consumption and also for sale in the local market. The goats and camels are generally raised for sale in the local market. Increasing salinity has arrested growth of mangrove and slowed down their regeneration.
All-over the worlds, tail ender interest are protected under historical riparian rights but the peoples of Sindh have always been the victim of injustice. The government has been putting great stress on water development projects in Punjab but they have never carried out studies for similar projects in Sindh.
At time when limited water resources are available for agriculture, this situation can be resolved if water is managed more efficiently, so that crop yield per unit of water consumption increases.
If government is really sincere to boost agriculture, suitable major irrigation project can be carried out in Sindh especially at Sehwan to the benefit of lower riparian.