They said a total of 215 kilometer-long water bodies in the city have already dried out.

The rally was organised by Save Environment Movement at Shahbagh crossing yesterday.

The speakers said government negligence had helped encroachers grab the canals and low lands by constructing buildings and markets.

They said five rivers surrounding Dhaka are also drying out creating excessive pressure on ground water. The water level is decreasing at an alarming rate along with a threat to landslide, they added.

Besides, a little rain also creates water logging in the city, they said.

The speakers also stressed on adequate supply of water during the dry season.

They called for enactment of new laws to keep the water bodies free from further grabbing.

The speakers demanded proper maintenance of the circular water way around Dhaka.

"We welcome the Wasa drive to clean-up the canals, but it must not end with the demolishing of the slums only but also the large constructions. Preservation of the canals from further grabbing and provision of clean water in the recovered canals are also essential," said Convenor of Save Environment Movement Abu Naser Khan.

The rally was attended by Columnist Syed Abul Maksud, Coordinator of Jono Uddog Sharifuzzaman Sharif, Green Force Coordinator Alamgir Kabir, Golam Kibria of Bishwa Sahitya Kendra, Environmental activists Subrata Dhar, Binoy Mondol, Romen Biswas, and Tarikul Islam.