ISLAMABAD: The recent pre-monsoon rain spell that lashed various parts of the country would improve the aquatic life of Rawal Dam as the reservoir is filled to its maximum capacity.

The dam, through which drinking water is supplied to the city of Rawalpindi, is home to various species of fish, turtles, and plants which creates a unique ecosystem.

However, this system is threatened by pollution in the reservoir, said an official from the Fisheries Department of the Islamabad Capital Territory (ICT).

The water in Rawal Dam is collected through rainwater which ultimately improves the growth of aquatic life.

The water along with dust and sludge brings various nutrients, micro plant species and organisms that create a healthy habitat for marine life, an official said.

He said the opening of spillways of the dam was another challenge that poses risk to the fish, adding people used to catch the fish by physically venturing into running water of the spillways jeopardising their lives. However, in order to tackle this nuisance, nets at a distance of 200-300 feet from the spillways have been installed.

The executive engineer of Rawal Dam, Amir Mumtaz, said that the total storage capacity of the reservoir was 1,752 feet which was at the moment filled up till 1,745.5 feet with an extra cushion of 7.5 feet. He said rainwater during the monsoon downpour used to fill the reservoir to its maximum capacity however when rains stop, water starts receding.

When contacted, Deputy Director of the department Mir Latif said rains used to bring nutrients and soil enriched with essential minerals that prove to be supportive for aquatic growth especially fish which are under threat during drought season.

He said sudden rise of water in the reservoir causes fish mortality, adding rain water accumulated in the dam turns greenish due to micro-plants brought with the deluge from catchments.

He said water settles in the dam within three or four weeks. While commenting about water pollution, he said the direct flow of household or sewage from Lakhwal village, Banigala and Murree were the major polluters.

He said small scale drainage of waste was not harmful but it could be fatal on a large scale, adding a water treatment plant was proposed to be installed near residential areas for purification of contaminated water but the proposal was dropped due to financial issues.

Later, residents of some areas suggested that soaking pits could be built near houses however this was not done by anyone and people keep dumping their waste in the dam.

According to the Met Office, the capital received 69 millimetres of rainfall.

Published in Dawn, June 27th, 2022