he Indus delta, once among the world’s richest and home to thriving farming and fishing communities, is disappearing gradually. Thousands of families are losing their homes, livelihoods and centuries-old way of life. They are forced to migrate to urban centres like Karachi, Sujawal and Thatta.

At the culmination of a 3,000-kilometre journey, the mighty River Indus meets the Arabian Sea through over a dozen creeks in the Indus delta spread over the southern districts of Sindh —Thatta, Sujawal and Karachi.

Stretching across nearly 600,000 hectares, or about 1.48 million acres, along Sindh’s coastline, the Indus delta is the world’s fifth-largest. It has been one of Pakistan’s most valuable ecological assets, supporting extensive mangrove forests, fertile agricultural lands, fisheries and remarkable biodiversity.

For generations, people living in the coastal districts of Badin, Thatta, Sujawal and Malir have depended almost entirely on the river for farming, fishing and forestry.

Today, however, declining freshwater flows downstream of Kotri Barrage are driving a growing environmental and humanitarian crisis. As river flows have declined steadily, seawater has advanced further inland, destroying fertile farmland, contaminating drinking water sources and forcing thousands of families to migrate for their livelihood.

The Pakistan Council of Research in Water Resources estimates that nearly 2.2 million acres of fertile agricultural land have become unproductive because of seawater intrusion. Satellite-based studies have revealed that more than 31,600 hectares (around 78,000 acres) were permanently submerged by the sea between 1972 and 2017.

Syed Qaim Ali Shah, the former Sindh chief minister, once told the Sindh Assembly that increasing sea intrusion was linked to the failure to implement the 1991 Water Accord. The accord, he said, required the release of at least 10 million acre-feet (MAF) of freshwater downstream of Kotri Barrage to maintain the ecological health of the Indus delta and slow the advance of seawater.

Asked about the federal government’s efforts to save the Indus delta, Federal Minister for Climate Change Dr Musadik Malik, told this scribe that a continuous flow of water throughout the year was essential to preserve the ecology of the Indus delta. In practice, he said, for most of the time during the year, there was no water downstream the Kotri Barrage. During the monsoon period, however, a lot of water flowed to the Arabian Sea.

The 1991 accord mandated the federal government to conduct research to determine the minimum healthy flow of freshwater downstream of Kotri Barrage. No such research has been commissioned.

For centuries, River Indus carried enormous quantities of freshwater and nutrient-rich sediments from the Himalayas, crossing the plains of the Punjab and Sindh to the Arabian Sea. The ecological balance began shifting during the latter half of the 20th Century. As the irrigation network and hydropower infrastructure expanded, increasing volumes of river water were diverted upstream for agriculture and electricity generation.

While these projects played a crucial role in supporting national development, environmentalists argue that they also significantly reduced the amount of freshwater reaching the delta. In the absence of sufficient river flows to push back seawater, saltwater gradually penetrated inland, triggering widespread environmental degradation.

Large areas of once-fertile farmland have become saline and unsuitable for cultivation. Many wells and underground freshwater aquifers have turned salty, leaving many villages without reliable sources of drinking water.

The consequences are visible across the coastal landscape. Large areas of once-fertile farmland have become saline and unsuitable for cultivation. Many wells and underground freshwater aquifers have turned salty, leaving many villages without reliable sources of drinking water.

Entire farming communities that once cultivated wheat, rice and vegetables now struggle to secure safe water. As agricultural production collapsed, many families abandoned lands cultivated by their ancestors.

Fishing communities have suffered severe losses, too. For decades, the fisheries sector formed the backbone of the delta’s economy. Healthy mangrove forests supported abundant populations of shrimp and fish, providing livelihoods for thousands of fishermen.

Today, rising salinity, declining freshwater inflows and marine pollution have weakened these ecosystems. Fish breeding grounds have deteriorated, biodiversity has declined and daily catches have fallen sharply.

Although the Sindh government and environmental organisations have launched extensive mangrove plantation programmes in recent years, especially after receiving carbon credits worth $40 million under the Delta Blue Carbon mangrove restoration projects in the Indus delta.

Despite a massive mangrove plantation campaign, climate change has further intensified the crisis.

Several villages have been partially or completely submerged. Families displaced by seawater often relocate repeatedly as the coastline continues to retreat. Scientists warn that unless freshwater flows improve, sea-level rise associated with climate change might accelerate the destruction of the delta during the coming decades.

Perhaps the most alarming consequence is the gradual migration of coastal communities.

Environmental experts increasingly describe the phenomenon as the Indus Delta Eco-Exodus, a migration driven not by conflict or violence but by the gradual destruction of a natural ecosystem that had sustained human settlements for thousands of years.

According to the Pakistan Fisherfolk Forum, more than 100,000 families migrated from the Indus delta between 1970 and 2025 because environmental degradation steadily destroyed their livelihoods.

Experts say the crisis extends far beyond Sindh’s coastline.

“The government should establish an Indus delta rehabilitation programme with an independent body to implement it,”says Nasir Panhwar, an expert in coastal climate. He says the plan should envisage the revival of lost species, protection of the environment, resettlement of the people and long-term integrated coastal zone management.

Moreover, he says, there should be a comprehensive assessment of losses and adequate compensation.

Each year of reduced river flows and advancing seawater pushes more villages closer to abandonment. Adam Janyaro, a local journalist, says that mostly fishermen and small farmers are migrating to city centres as their livelihoods have diminished in recent years. This exodus is still going on.

The writer is a development communication professional based in Karachi