Silt halves Sukhna’s storage capacity

Amarjot Kaur

Tribune News Service

Chandigarh, January 12

The storage capacity of Sukhna Lake has fallen by nearly 50 per cent since 1958 but the UT Administration seems to be little bothered about its desilting. 

In 1958, the lake, spread over 565 acres, had a storage capacity of 8,710 acre feet, according to the data with the UT Engineering Department. 

As per a 2015 survey, the water body has shrunk to 405.52 acres and its storage capacity fell to 4,416 acre feet.

However, this data does not match with that of the city’s Forest and Wildlife Department. According to the figures with the department, the lake’s capacity shrank by 23.24 per cent till 1964, 38.22 per cent in 1969, 49.30 per cent in 1974 and 63.03 per cent in 1989.

In spite of its fast-falling capacity and area, the lake has not been desilted since 2012. The Engineering Department had removed 7.75 lakh cubic feet of silt in 2009, 108.16 lakh cubic feet in 2010 and 92 lakh cubic feet in 2012.

Subdivisional Engineer SS Grewal said they would be able to desilt the lake only if it dried up completely. “IIT-Roorkee has advised us against desilting the area, when there’s water in it. Also, it is not possible to fill it over and over again with the help of tubewells. Only rainwater coming from the catchment area can fill it but dense vegetation doesn’t allow the water to reach the lake. Also, the water coming from the catchment has silt in it, but that’s a natural and inevitable process.”

Zoologist AD Ahluwalia, who volunteered for desiltation in 2012, said the problem was common among lakes in the country. “Desiltation is not the only solution. In several countries, people are releasing pollution-eating algae. Dams should be constructed too,” he said.

UT Chief Conservator of Forests said the department had already made over 100 dams to ensure the minimum invasion of silt. “Earlier, there weren’t many trees here, so silt would flow into the lake. Now, we have not only planted more trees, but also made over 100 dams to check the flow of silt into the lake,” he said.

MS Johal, an environmentalist and retired professor of the Zoology Department at Panjab University, who has been a member of the Save Sukhna Committee and the Wetland Regulatory Authority of UT, said the Administration-formed authority had met only once this year. “The formation of a technical committee was proposed but nothing has happened yet. Silting is bound to take place, but desiltation is the only way out; may be adding extra water can be of some help, too.”

Ecologist RK kohli, who is the VC of the Central University of Punjab, Bathinda, said even though succession (reduction in the size) of water bodies and wetlands is natural, its speed in the case of the Sukhna was worrisome. “For now, I don’t see a solution because the soil on the foothills of the Shivaliks is loose and it’s bound to flow down to the Sukhna in the rainy season,” he said. 

Silt stats

• In 1958, the lake, spread over 565 acres, had a storage capacity of 8,710 acre feet. As per a 2015 survey, the water body has shrunk to 405.52 acres and its storage capacity fell to 4,416  acre feet.
• The Engineering Department had removed 7.75 lakh cubic feet of silt in 2009, 108.16 lakh cubic feet in 2010 and 92 lakh cubic feet in 2012.
• Subdivisional Engineer SS Grewal said they would be able to desilt the lake only if it dried up completely. Grewal added that the IIT-Roorkee had advised them against desilting the area, when there’s water in it. 
• “Also, it is not possible to fill it over and over again with tubewells. Only rainwater from the catchment area can fill it but dense vegetation doesn’t allow the water to reach the lake.