Challenges to the River Indus and its connected irrigation network, including pollution caused by disposal of effluents, are unending. This undermines ecology of the river and its canals and also contributes to public health issues. Contamination remains a perennial problem of the river.

Effluent disposal is also a violation of successive directives passed by the Supreme Court. The judicial commission on water and sanitation had also submitted its findings before SC before it was dissolved by then Chief Justice Gulzar Ahmed in February 2020. The commission, while quoting a study by the irrigation department, had mentioned 750 points where untreated municipal waste fell into the irrigation system.

Right from Guddu Barrage to undivided Thatta district – downstream Kotri Barrage where it meets the Arabian Sea – River Indus and its irrigation networks serve as a lifeline for a huge population besides irrigating agriculture farms. Sea intrusion, on the other hand, is devouring land and contaminating groundwater in lower Sindh’s districts of Badin, Sujawal and Thatta continuously in absence of adequate freshwater flows to multiply farmers’ miseries amidst inadequate irrigation supplies.

In addition to its contamination within provincial boundaries, the River Indus is being polluted by effluents from parts of Punjab from upstream Guddu that finds its way into the river. After entering Sindh, the river and its 14 canals at three barrages work as key drinking water sources for 55m population. The canal network receives domestic wastewater in addition to effluents both in urban and rural areas.

Untreated domestic wastewater flows into the river, carrying faecal bacteria; agricultural runoff carries toxicity of pesticides and fertiliser

Untreated domestic wastewater carries faecal bacteria and other germs. Agricultural runoff carries toxic waste of pesticides and fertiliser, as per the Sindh Environmental Protection Agency (Sepa).

Such disposal remains untreated as sewerage treatment plants don’t exist in Sindh except for the combined effluent treatment plant (CETP) at Kotri. It doesn’t regularly work, either. Resultantly, untreated waste from Kotri’s large industrial base goes into Kalri Baghar Feeder.

Early this year, the Indus River System Authority (Irsa), the water regulator that oversees interprovincial water distribution, had expressed concerns at worsening water quality of surface water resources due to pollution, salinity, odour and other factors in the Indus Basin Irrigation System (IBIS). The Irsa chairman wrote a letter to provincial chief secretaries and quoted field observations revealing pollution—specifically foaming and foul odour — at major barrages, including Sukkur and Kotri and Aral Head Regulator of Manchar Lake. It said salinity levels increase during low flow months—Rabi season.

The Manchar Lake across Jamshoro and Dadu districts has been destroyed due to toxic wastewater it receives from Right Bank Outfall Drain-I or Main Nara Valley Drain (MNVD). Its water quality analysis, from time to time, has found zinc, lead, copper, chromium, nitrates, pesticides etc. Its degradation continues unabated to date.

The lake’s revival is linked with completion of the Right Bank Outfall Drain–II project that has been pending for decades. The Sindh government seems indecisive about completion of the project. It’s unclear whether the provincial irrigation department plans some alternate of the project or it completes the drain with some new alignment. But the project that started in 2001 was to be completed in 2006 at a cost of Rs14bn. It remained incomplete despite multiple cost overruns. Story doesn’t end here. Flows from the lake were released into the River Indus upstream Kotri Barrage to keep the lake’s bank in safer limits.

According to water technologist Dr Ahsan Siddiqui, Manchar Lake’s water carries heavy metals like magnesium, chloride, sulphate and sodium in higher than permissible limits. Industrial waste carries chromium, produced in dyeing mills while abnormal ranges of compounds like cadmium yellow, red, green were found in wastewater released by food industry specially pulse mills into KB Feeder and Phulelli canals.

“Presence of arsenic and mercury in the lake water is indicative of agriculture runoff ending up in Manchar. Although their range has comparatively dropped over the years, it is still found in water,” says Mr Siddiqui.

When released, such flows affect the River Indus water quality despite the fact that drinking water supplies of the cities like Hyderabad, Jamshoro, Thatta and even Karachi (through Kalri Baghar Feeder of Kotri Barrage) directly come from the river. Kalri Baghar feeds Keenjhar Lake which serves as a vital source of drinking water for the provincial capital but not before it gets contaminated in Jamshoro, thanks to releases of the hospital and domestic wastewater.

While cities like Hyderabad luckily have, though dysfunctional until recently, filtration plants to treat water of the River Indus, rural areas lack such luxuries, posing serious health risks to their population that face waterborne diseases after the contaminated water enters the food chain.

Like the Kalri Baghar feeder, Kotri Barrage’s old Phulelli/Pinyari Canal receives a huge volume of untreated domestic wastewater of Hyderabad and Latifabad on a daily basis. The canal provides water to the agriculture sector for sugarcane and rice growing areas besides drinking water supplies for Tando Muhammad Khan and Sujawal districts. A treatment plant—Eastern Sewerage Treatment Plant (ESTP)—conceived in 2006 remains incomplete at a point in Hyderabad city where sewage enters the canal. It was so in spite of the expenditures of Rs660m out of Rs915m. Its cost was revised to Rs2,804m and now another revision would be needed if it is to be executed, which was worked at Rs3,507m.

The Sindh Irrigation Department has launched a ‘Karo Ghungroo outfall drain’ that would now also include a component to divert water from the canal that would outfall somewhere in Tando Muhammad Khan before heading for sea. The drain otherwise was to carry Karo Ghungroo main drain and Karo Ghungroo branch drain in addition to two small old and new Deewan drains.

Sepa Director General Ashiq Ali Langah believes that different government departments, including local government, municipal corporations, public health engineering, Sepa, industries, irrigation and health, district administrations and they all would have to get their act together to take responsibility.

“Roles and responsibilities are already clear. They are supposed to protect freshwater resources in different ways. If Sepa is to enforce regulations to ensure water quality standards or disposal of wastewater into water bodies, the irrigation department will have to control drainage’s releases into the canals,” he says. Similarly, Mr Langah adds, the district administrations would have to check the river pollution by taking various administrative measures like punitive action against those responsible for polluting the river or canal water.

Published in Dawn, The Business and Finance Weekly, November 9th, 2026