Possitive Impact on environment says experts
At a time when strong floods and heavy rains are causing unprecedented devastation in the entire country, some environmentalists in Sindh believe that millions of cusecs of water will have a positive impact on environment in the province.
“On one hand, floods are causing loss of lives and properties, but in the long run, it would clear our lakes of chemical and biological contaminations, refresh our water resources, reduce salinity in the delta and would be a blessing for fishermen,” one expert told The News when asked about the impacts of floods in the downstream Kotri.
Currently, the Asia’s biggest freshwater Manchar Lake has become a source of concern for the authorities for becoming extremely poisonous due to dumping of fertilizers, chemical wastes, agricultural run-off and domestic and industrial effluent in the wetland.
The Supreme Court of Pakistan is at the moment hearing a case on the contamination of the Manchar Lake due to dumping of toxic chemicals in the freshwater reservoir.
However, noted environmentalist and former director-general of the Sindh Environmental Protection Agency (SEPA) Iqbal Saeed Khan says the Manchar lake could be cleared of much of its toxicity by diverting floodwater into the lake.
“This flood has created an opportunity of cleansing the Manchar Lake of its contamination. The ball is now in the court of Irrigation Department officials as only they can use the floodwater to flush out toxicity from Asia’s biggest lake,” he observed.
According to him, dumping of fertilizers and agricultural waste along with all kinds of chemicals had created a thick layer of green algae on the Manchar Lake that had destroyed its aquatic life.
“This thick layer of algae became dead over the time and now it is preventing sunlight and oxygen from penetrating into the water. Both these elements — sunlight and oxygen — are immensely important for aquatic life as well as killing harmful bacteria in the water,” he maintained.
However, floodwater and heavy rains, he said, could be used to refresh the natural resources like the Manchar Lake as well as Keenjhar, from where drinking water is supplied to Karachi.
“The Keenjhar Lake is also becoming contaminated due to dumping of industrial waste of the Kotri industrial area into this freshwater source of drinking, fishing and agriculture. These rains and floodwater would also have a positive impact on its cleansing or at least dilution,” he claimed.
On the other hand, millions of cusecs of water in the downstream kotri would also be a good omen for the fishermen and the aquatic life as well as the Mangroves, he added.
Similarly, floods and rains would also reduce salinity in the Indus delta due to sea intrusion, Iqbal Saeed Khan said, adding that fishermen in Sindh were delighted so much water was coming into the Indus River after such a long time.
Sepa Director Technical Waqar Phulpoto also confirmed that flood in the Indus River and heavy rains could have a positive impact on the freshwater resources of Sindh, but said that proportion of the devastation caused by these floods was much higher.
“I believe that contamination in lakes, especially Manchar, would reduce due to dilution as freshwater would definitely clear some toxicity from the lake. Flood and rainwater would be helpful in the Indus delta region, especially for Mangroves and reducing salinity,” he added.
Phulpoto said he had personally visited interior of Sindh where crops, especially the cotton crop, were badly damaged due to heavy rains and floods. “But as far as the positive impacts of the floods in the downstream Kotri is concerned, they are quite evident and would be a lot helpful for the local fishermen community,” he maintained.
He said after the monsoon season, the Sepa would carry out an assessment of the damages and the level of toxicity in freshwater resources of the province. However, another Sepa official, Shahid Farhad, was skeptical of any positive change in freshwater resources, especially the Manchar Lake, saying only a controlled diversion of water into the lake will help to flush out all the toxic chemicals. “Actually, the Met office had warned us about heavy rains and floods weeks back and if then something had been planned by the irrigation department officials, the Manchar Lake could have been cleared of all the chemical and biological contamination,” he claimed.
On the other hand, he said the flood coming from Khyber-Pakhtunkhwa could also be carrying lots of contaminations, including ecoli bacteria, agricultural run-off.
Shahid Farhad said theoretically it was possible that rains and floods wash away all the contaminations from lakes water but the actual situation could only be assessed after proper evaluation.
