ON Jan 21, the Sindh irrigation department started releasing poisonous water from Manchhar Lake, bringing back disturbing memories of May 2004 when over 20 people lost their lives and many others fell sick after consuming the contaminated water.

The 80 cusecs of harmful water, flowing into Indus River via Aral Canal, is passing through the vicinity of Hyderabad now. In 2004, the total discharge from Manchhar stood at 600 cusecs.

This year the release from Manchhar has been made in winter when a meagre amount of fresh water is coming from Sukkur Barrage due to water shortage. This quantity of fresh water — 3,285 cusecs only — will get further reduced by at least 30 per cent owing to evaporation and seepage when it reaches the Kotri Barrage.

In 2004, the poisonous water was released without any announcement by the authorities, causing maximum harm to unsuspecting people of Sehwan and Hyderabad and dozens of villages along the Indus. The tragic incident sparked uproar in the media, forcing the government to set up a small laboratory near Manchhar Lake aimed at ascertaining the quantum of poisonous content in its water.

In 1990, a gigantic ‘Right Bank Outfall Drain’ was built. The objective was to throw saline water and effluents coming from Punjab, Balochistan and upper parts of Sindh into Manchhar Lake from where it was to be disposed of into Indus.

However, ‘inaccurate data’ rendered RBOD a useless project.

It was estimated that the amount of effluents thrown into the lake will be so small that ‘almost’ no adverse effect will befall its users. On the contrary, it was so high that one year after the RBOD’s construction flora and fauna in the area started diminishing.

Sindh lodged a strong protest with Islamabad, and in 2001 it was agreed that instead of exploiting Manchhar Lake for the purpose, the RBOD would be extended to take the effluents directly to Gharo Creek by passing through Nai Baran and Kotri.

In Nov 2003, Sindh complained to the centre that the province would turn into a desert if effluents continued to flow into Manchhar Lake.

Wapda insisted that there was no alternative but to drain saline water into the lake. However, upon intervention by then prime minister Mir Zafarullah Jamali it agreed to divert Balochistan’s 1,600 cusecs of saline water to RBOD-II to carry it to the sea without passing through Sindh.

This year, effluents falling into Manchhar have already reached the level of 112.35 feet which, if not reduced, has potential for causing flood. In order to reduce the level, the irrigation authorities had started releasing the lake water on Jan 17. However, the Hyderabad authorities got it stopped so that it could store fresh water for a week or so.

On Jan 21, the release from Manchhar resumed. According to the irrigation authorities, the water level at Manchhar has to be brought down to 110ft which means the release of poisonous water will continue roughly for 10 days.

They claim that the present discharge of poisonous water has a ratio of 1:30 which ‘would not pollute the water’. When the 2004 incident took place, the ratio of contamination was 500-600 parts per million, significantly higher than WHO’s standards of 400 parts per million.

The authorities have yet to make public the quantity of poisonous content in the Manchhar Lake. This time the water from Indus will not be used for irrigation immediately, but it will be used for human consumption.

Therefore, there is a need to find an immediate remedy. The authorities should ensure timely completion of all the sections of RBOD so that effluents could be channelled to the sea without people being exposed to it.