Heavy rains improve aquatic life in Rawal Dam
The heavy pre-monsoon rainfall has filled the Rawal Dam to its maximum capacity, reviving the endangered marine and aquatic life of the reservoir besides giving it an ecological uplift.
An official of the Islamabad Fisheries Department said that the rainwater coming from the Margalla hills catchments will help improve the growth of aquatic life. He said that aquaculture in the reservoir improves the quality of water which in turn helps synthesise healthy habitats for marine life.
According to the Met Office, the federal capital received a rainfall of 69 millimetres which was one of the highest recorded in various parts of the country.
Rawal Dam, which supplies drinking water to the city of Rawalpindi, is home to various fish species, turtles, and aquaculture that creates a unique ecosystem threatened by man-made activities in the reservoir, said the official.
"The rainwater along with dust and sludge brings various nutrients, micro plant species and organisms that help the aquaculture in the reservoir improve the quality of water which in turn helps the synthesis of healthy habitat for the marine life," said the official.
He said the opening of spillways of the dam was also another challenge that poses risk to the fish. "The dam authorities are advised to avoid abrupt aperture of spillways that cause big fish to drift, rendering loss of precious species.
People catch fish from the running water of the spillways which directly jeopardised individuals' lives. However, to tackle this issue, the fisheries department has installed nets at a distance of 200-300 feet from the spillways to avoid drifting of fish.
Executive Engineer of Rawal Dam Amir Mumtaz said that the total storage capacity of the reservoir is 1,752 feet which has filled to 1745.5 feet till now with a cushion of 7.5 feet capacity still available for storage.
Deputy Director Fisheries Department Rawalpindi Mir Latif said that the rains bring nutrients and soil enriched with essential minerals that prove to be supportive for aquatic growth, especially for fish which are under threat during drought season.
He said that the sudden rise of water in the reservoir causes fish mortality with immediate water bed turnover.
Latif said that the rainwater accumulated in the dam turns greenish due to micro-plants brought with the deluge from the catchments and it gives healthy habitat for the growth of fish.
He said the water settles in the dam within 3-4 weeks at the same time as the aquatic life develops, however, if the thunderstorm and heavy rainfall persists then it could disturb water species synthesis. "It develops instantly in favourable conditions, he added.
While commenting on the water pollution jeopardizing the water life, he said the direct flow of household or sewage in Lakhwal village; Bani Gala residential area and Murree Brewery were the major polluters.
He said the small-scale drainage of the waste is not harmful while the large scale can prove to be fatal. A water treatment plant was proposed to be installed near the residential areas for purification of the contaminated water which was dropped due to financial issues, he said.
Later, soaking pits were advised to be built by the area residents besides their houses which were constructed in the beginning by the residents of Bani Gala, he said.
Latif said that the new Bani Gala residents were not developing pits and were dumping their sewage in the dam which was causing harmful impacts on the water species.
Published in The Express Tribune, June 25th, 2022.