Extractive and wasteful water use has created a severe crisis for the Indus delta, where the Indus River flows into the Arabian Sea. This natural confluence of outflowing freshwater and the sea not only prevents sea water intrusion, but it has also created an interlinked system of swamps, streams and mangrove forests. This delta ecosystem provides a unique habitat to a diverse range of species, including migratory birds and one of the world’s rarest dolphins, the blind Indus River dolphin, all of which are currently under great stress.
The delta covers an area of over 40,000 sq-km, which makes it the world’s fifth largest delta system, containing within it the seventh largest mangrove forest system. The Indus delta is mostly located in the southern Sindh province of Pakistan with a small portion in the Kutch region of India.
The Indus delta has been under stress for quite a while now. The British constructed vast canal networks on the Indus, turning arid or semi-desert tracts into irrigation-dominated agricultural zones to grow cash crops. However, these agricultural schemes did not only expropriate pastoral lands and hand them over to loyal colonists, including retired soldiers which had served the British Raj, but they also caused major ecological disruptions. Poor drainage led to rising water tables, waterlogging and salinisation due to which many formerly productive areas became infertile. Following independence, the Pakistan government began to invest in large dam projects with support from entities like the World Bank. The increasing diversion of Indus River for irrigating cash crops has not only reduced flows downstream, but it has also done persistent damage to the Indus delta and its wetlands.
At a time when there is increasing need for efficient water use, water conservation and environmental sustainability, the water regime in Pakistan remains wasteful and extractive. Besides excessive water extraction, runoff chemicals and other pollutants are other major threats to the Indus delta.
The US-Pakistan Centre for Advanced Studies in Water estimated a few years ago that the downstream flow of water into the delta has decreased by 80 per cent since the 1950s. Besides irrigation canals, hydropower dams, climate related impacts on glacial and snow melt have also been identified as major factors for this decreased outflow, which has, in turn, caused major seawater intrusion. The salinity of the water in coastal areas has increased by alarming levels making it very difficult for local farming communities in the delta to grow crops. Increased salinity is leading to higher blood pressure and a resulting spike in mother and child mortality rates in many coastal towns in Sindh, according to a recent Lancet study.
The Indus delta is also shrinking. A Jinnah Institute study has estimated that more than 1.2 million people have been displaced from the overall Indus delta region in the past two decades. The outmigrant of these poor people is adding to the unsustainable growth of megacities like Karachi, which is already unable to cater to the inflow of other flood-induced displaced populations, as well as the unrelenting stream of economic migrants.
Reviving the Indus delta so that it can continue to serve its vital ecological function, and remain a habitable region for traditional coastal communities, is not going to be easy. Making the delta healthy requires multiple efforts. It necessitates restoring freshwater and sediment flow via well managed water release from upstream dams. The rehabilitation of mangroves, addressing the pollution of upstream waterways and putting in place climate mitigation measures, such as glacial regrafting, are also vital. Some efforts to address these issues are being undertaken via the Living Indus Initiative. However, India’s revocation of the imperfect water sharing treaty, and greater emphasis on both sides of the border to build more intrusive infrastructure will not bode well for the health of this precious delta.
