Manchar is a beautiful, picturesque lake. " Man " means "jewel," while " char " means "an expanse of water." The lake is oval in shape, extending northwest to southeast for about 10 miles with an average breadth of about 3 miles. Its depth varies from 8 to 16 meters.
After the rains, the lake doubles in length and width. In the dry season, the area of the lake is 30 square miles while after the rains, the lake spreads across an area of 200 square miles. The lake is fed by the Nara and Aral Rivers. According to tradition, the lake is a bathing place for fairies and mermaids. There are several small islands in the lake. The main islands are Lal Chatto and Mashak. The lake is also famous for fowls and fishes.
Manchhar, Pakistan's largest fresh water natural lake, is located in district Dadu, at 26°25N 67 °39E coordinates about 300 kilometres north-west of Karachi in the Kirthar valley. With riverine forests on the south-east side and the river Indus on the east, the picturesque lake has special significance in the history of Sindh.Altitude of Manchhar is 35m.The area of Manchhar lake is 6,000ha.
Manchhar lake is located on the international route of migratory birds. Being the largest reservoir and the first wetland on the route of the birds, it attracts birds in the thousands every year. Most of these migratory birds spend the entire winter season on these waters. Species like Anas crecca, Fulica atra,Pelecanus crispus, Haliaeetus leucoryphus, little ringed plover, wood sand piper, waders, wagtails, nightingale, parakeet, storks, ducks and a host of local species add colour and life to the beauty of the lake. About 20,000 to 30,000 colourful birds visited the lake annually in the past, but pollution has caused a reduction in the number of visiting birds.
Once a beautiful lake with daffodils and lotus flowers attracting colourful migratory fowl from the chilly Siberian plateau, Manchhar lake, the habitat of the Mohanas, has been turned into a poisonous cesspool by the discharge of toxic waste from the Right Bank Outfall Drain (RBOD). The once blue water of the lake has turned into greenish filth, and it has become unfit for human consumption.
"The recorded catch of the lake was once about 2,300 tons per annum, but it now stands at barely 300 to 400 tons per year," says Ghulam Qadir Rodhnani, a local landlord and fish trader. "Poisonous water is killing our fish and us," says Yar Muhammad Mallah, 65 one of the Mohanas of Manchhar
Outcomes of pollution
Under the RBOD project, sewerage water and drainage, drawn from water-logged and salinity-hit areas of the upper parts of the country, mixed with chemicals and fertilisers from rice cultivation in upper Sindh is being disposed off in the lake through the Main Nara Valley (MNV) drain.
"The number of birds has been drastically reduced in recent years and they now have a shorter stay," confirms Jehangir Durrani, conservator (Wetlands), World Wide Fund for Nature (WWF) Karachi. He says that pollution has disturbed the big-diversity of Manchhar lake.
The MNV carries about 2,100 cusecs of effluent water with a salinity ratio of over 5,000 particles per million (ppm) to Manchhar lake, while WHO's allowed maximum safety level of water for human consumption is only 640 ppm. The situation in and around the lake is very serious.
Due to the pollution, fish catch has reduced and people are facing difficulties in getting water for drinking. Samples taken from Manchhar lake show that the salinity was over 3,000 mg/litre for most of the samples, against the desirable limit of 500 mg/litre for the fisheries and 1,000 mg/litre for drinking purposes.
The entire lake has become saline and the salinity level is increasing day by day. Besides affecting fish, pollution has caused a reduction in the number of visiting water fowls that stay on the lake every winter. Tourism has also been affected and fishermen are migrating to other areas. The pollution is also affecting the surrounding fertile agriculture lands which are irrigated by the lake water, and this has reduced the crop production and rendered thousands of people jobless.
Presently, this effluent is disposed into Manchhar lake through the Main Nara Valley (MNV) drain. The completion of the 24-km-long Indus Link would end the degradation of Manchhar, but will pose problems of its own. Environmentalists fear that is would endanger human life and the agricultural system and environment in and around the Kotri barrage. The proposed link would connect the MNV drain with the river Indus near Bhan Saeedabad town in Sehwan subdivision of Dadu district. This will disturb the bio-diversity of the river besides posing a threat to human life and irrigation systems in lower Sindh
Drastic measures are needed to be taken to reduce the eutrophication level of this important bird area.
There should be a strict check on the discharge of effluents from side by towns.
The biochemical and biodiversity status of lake should be studied and be submitted to IUCN and WWF, Possibly on the yearly bases
The birds count and observation should be made by a monitoring system so that the fluctuation in the population of birds could be assessed.