Agriculture: Jeopardising the future of the Indus delta

The proposal to construct six new canals on the Indus River to irrigate the Cholistan desert in Punjab is being seen as a direct threat to Sindh’s already fragile ecology and irrigation system. These canals were intended to bring water to an arid region that had historically relied on rainfall and underground reservoirs for irrigation. Therefore, diverting water from the Indus to Cholistan is unjust, especially when Sindh’s water needs are not met.

Any new canals on the Indus River would not only impact Sindh negatively but would further jeopardise the future of the Indus Delta. The Sindh government has already expressed serious concerns about the proposed new irrigation project in Punjab. Sindh, being a lower riparian province, has been demanding adequate water flow for downstream Kotri to maintain ecological balance in the Indus Delta.

The Indus Delta, the fifth largest delta in the world, is characterised by its rich biodiversity and valuable ecosystem services, including productive fisheries and coastal storm protection by mangrove forests. The Indus Delta was designated a Ramsar wetland of international importance under the Ramsar Convention on November 5, 2002.

The reduced Indus River flows, and sediment loads coupled with sea level rise are driving a multifaceted environmental crisis for the Delta, including seawater intrusion, soil salinisation, mangrove forest loss, reduced freshwater supply, and depleted fisheries. The 17 creeks that once delivered freshwater to the Delta have been reduced to one, and no freshwater reaches the delta for 138 days per year on average, and even longer periods during drought years.

Degradation of the Indus Delta costs around $2bn annually as little effort is made to monitor or mitigate damage

The water-dependent ecosystems in the country are under increasing stress from high levels of water withdrawal, widespread pollution, rapid urbanisation, and agricultural expansion. Biodiversity loss, declining fish stocks, and degradation of the ecosystems of the Indus Delta, which offer valuable ecosystem services, are increasing, with little effort to monitor or mitigate this damage.

According to a World Bank study, the cost of degradation of the Indus Delta is estimated to be over $2 billion annually because of foregone ecosystem services. Environmental degradation in Sindh alone costs an estimated four per cent to 6pc of the provincial GDP.

The 17 creeks that once delivered freshwater to the Delta have been reduced to one, and no freshwater reaches the delta for 138 days per year on average

Unfortunately, the upstream diversions of the River Indus by unchecked development of water infrastructure during the 20th century have caused a gradual reduction in the water flow of the river. It is ultimately affecting its uniqueness and economic value and has seriously affected riverine and coastal ecologies and their associated and dependent communities.

The Water Accord in 1991 recommended at least 10 million acre feet (MAF) perpetual water supply in the Indus River for the downstream deltaic ecosystem. The International Union for Conservation of Nature recommended an essential release of 27 MAF for the continued well-being of the deltaic ecosystem. These recommendations, however, have not materialised so far.

Given the level of water resource development upstream, flows downstream of the Kotri barrage are now limited to August and September, allowing seawater to penetrate the delta for hundreds of kilometres for much of the year. The mangrove forests support the livelihoods of more than 0.1 million people, and further shrinkage would put these livelihoods at risk.

Shrimp production and the catch of the prized Palla fish have fallen by more than 90pc. The reduction of the mangrove forests has had significant impacts on biodiversity because they are an important wintering habitat for migratory birds on the Central Asian flyway. The loss of mangrove forests has also compromised their ability to act as an active barrier against tropical cyclones and storms, leaving the delta at greater risk of coastal erosion and flooding.

Currently, Pakistan does little to protect water-dependent ecosystems such as rivers, lakes, wetlands, forests, and the Indus Delta through either water quantity or water quality management. No environmental flow regime has been agreed upon or implemented for the Indus River. The delta has witnessed meagre environment flow, and the number of “no flow days” has increased substantially.

The environmental river flow is essential for controlling seawater intrusion. Therefore, enough water flow in the river Indus, as well as canals originating from the Kotri barrage, should be ensured to minimise surface and subsurface seawater intrusion in the entire delta. It will not only minimise surface and subsurface seawater intrusion but also provide drinking water to coastal communities, fulfil the freshwater needs of flora and fauna, and mitigate the adverse impacts on the ecosystem of the delta.

The author is a development professional and author of the book “Earthly Matters”

Published in Dawn, The Business and Finance Weekly, November 4th, 2024