Chalan beel has to be declared as an "environmentally critical area" and a separate and independent body has to be formed to take up planned development projects giving priority to the environmental issues, said speakers at a programme yesterday.
They said the character of Chalan beel that separated it from other plain-land water reservoirs for centuries was its water flow. From its flowing current, its name was chosen.
Now, the beel which is still considered the country's largest water reservoir, has not only lost its flow, but also its capacity of holding water with its declining water level, they said.
Bangladesh Environmental Lawyers Association (Bela), Rajshahi chapter and the Association for Land Reform and Development jointly organised the virtual discussion on "Steps to protect Chalan beel".
The speakers said the biodiversity is under threat due to mindless development projects blocking water flow, grabbing of beel lands, pollution by factories and the recent spree of digging unplanned ponds.
Addressing as chief guest, Prof Golam Sabbir Sattar, chairman of Environmental Science Institute of Rajshahi University, said the Chalan beel has a history of 700 years.
Stressing the need for protecting it, he said it is terrible that the beel -- which used to hold water round the year -- is now facing a declining groundwater.
SM Mizanur Rahman, member secretary of Chalan beel protection movement of Pabna's Chatmohor, said around 10 lakh submersible pumps are used to withdraw groundwater to cultivate Boro paddy in the beel.
Hundreds of ponds were dug in an unplanned way there for fish cultivation, turning a lot of land uncultivable, he said.
Presenting the keynote, Tanmay Kumar Sanyal, coordinator of Rajshahi chapter of Bela said, some 50 lakh people lived in the beel situated on 13 upazilas of four districts -- Natore, Pabna, Sirajganj and Naogaon.
The beel -- constituted of 150 small beels, 23 rivers, 350 canals, 20,000 government and one lakh private ponds -- used to flow with river water channeled through Boral river, he said.
It was once home to 260 kinds of fishes, crocodiles, dolphins and hundreds of birds, said Tanmay Kumar, adding that now crocodiles and dolphins are history while the number of fish varieties has fallen to 160.
The land that was fertile enough to produce varieties of crops, nowadays produces nothing but paddy, garlic and mustard, he said.
The keynote identified seven causes of degrading the beel's environment -- including 50 unplanned sluicegates and water regulators, 2,005 culverts, 150 bridges, a rubber dam, 150 brick kilns, releasing untreated liquid from factories, and navigation crisis of rivers.
The participants demanded free flow of water of the rivers and canals of Chalan beel, stop to using the groundwater, and holding public hearing and assessing environmental issues before implementing any infrastructural development.