HYDERABAD, Jan 1: Discharge of water from the Manchhar Lake into the River Indus to reduce level of the lake, which is attaining an alarming proportion, has been stopped in the wake of no discharges at Sukkur downstream at the River Indus.

The Sukkur Barrage has been closed for annual maintenance work, which will continue till around January 15. Similarly, closure of the Kotri Barrage is also in progress as part of an annual exercise.

Since there is zero discharge of water at Sukkur downstream, water technologist of the Hyderabad district government, Dr Mohammad Ahsan Siddiqui, has ensured that the discharge of water from the lake should be stopped as long as there is a nil discharge at downstream Sukkur.

“The discharge from the lake into the River Indus has been stopped from today morning (Thursday) on my recommendation because there is hardly 4,000 cusecs of water available at Kotri upstream and it will not help dilute lake’s water with that of the River Indus,” Mr Siddiqui told Dawn.

There has been no water releases from Sukkur downstream for upstream at the Kotri Barrage for a couple of days therefore discharge of the lake’s water to reduce its level had to be stopped.

The level of the Manchhar Lake is reported to be 113.40 RL (reduced level), which indicates that the lake has been receiving constant and heavy discharge through RBOD-I, which is also known as Main Nara Valley (MNV) drain.

The values of lake’s water remained abnormal as it shows high concentration of arsenic compounds and presence of mercury and magnesium. According to Mr Siddiqui, test results of lake’s water showed that 3,000 total dissolved solids (TDS) were recorded in it at Aral Wah regulator against their normal range of 500 TDS at the maximum.

Likewise, chloride was recorded at 930 part per million (PPM) against 200 PPM, which is normal value; mercury at 21 part per billion against 1 normal range; arsenic 60 PPB against 10 PPB; magnesium 430 PPM against 40 PPM and calcium at 350 PPM against 100 PPM.

“If concentration of magnesium is high in water then it will cause gastrological disorders while mercury’s high value could lead to abnormal movements or even blindness and neurological damages while arsenic compound causes skin diseases,” said Dr Siddiqui.

A provincial water release committee had approved discharge of the lake’s water into the River Indus in its Dec 18, 2008 meeting in the light of Dr Siddiqui’s recommended ratio of 1:23.

The definition of the ratio is that if there is 1,000 cusecs of water from the lake then there has to be availability of 23,000 cusecs river water at the spot where the lake water is to be released.

The committee was formed in the year 2004 when Hyderabad and its adjoining towns were affected by an unprecedented water crisis, which caused deaths of 42 people due to consumption of poisonous water of the Manchhar Lake that was released into the River Indus without informing the Kotri Barrage authorities and taking the Water and Sanitation Agency onboard.

The level of water could only be reduced, said Dr Siddiqui, by 0.10 RL (current level is 113.40 RL), which is reflective of the fact that the lake is receiving heavy quantity of effluent from MNV. The lake’s level is to be maintained below 114 RL to ensure safety of the lake’s embankments because any breach or overflow of water could cause loss of lives and properties of fishermen.

Recent spell of rains had also increased flow of effluents of the MNV drain but it simultaneously also had a positive impact on the River Indus condition.

Rains and the subsequent flow from Nai Gaj in the form of hill torrents into the River Indus increased water availability that ultimately helped dilution of the lake’s water.