Strong monitoring and enforcement by the government will be necessary to avoid pollution and maintain good water quality supply in the Meghna river, the Asian Development Bank (ADB) says in a report.

This publication explores the potential of the Meghna as an alternative water source for Dhaka. It also describes the fragile state of the city's current drinking water supply due to increasing demand and surface contamination.

The authors assess the threats facing the Meghna river and identify protection measures needed to ensure that it can provide a sustainable and safe supply of drinking water.

These measures include designating ecological critical areas, promoting cleaner industrial production, monitoring pollution, controlling wastewater discharges and pesticide use, and empowering local stewardship of the river.

The joint institutional setup by DoE and Dhaka WASA, and in collaboration with local administration should be an effective arrangement. Declaring an ECA for the protection of biodiversity will in turn protect the two water intake points, it said.

The report recommended equipping newly-declared economic zones in the Meghna river area with state-of-the-art production methods and adequate treatment facilities or central ETP.

It suggested bringing under compliance small and medium-sized industries lacking ETP or those operating poorly. "Cleaner production is recommended to reduce discharge load and maximise profit," it said.

The report said solid waste and wastewater from municipalities should not be directly discharged into the river.

"The DOE should take appropriate action in applying its regulatory instruments ... [and] require all new development proposals along the Meghna river to include assessment of the cumulative impacts on water quality," the report said.

ADB suggested the government to continue the river water quality monitoring programme conducted under the TA and install a continuous monitoring system with an early warning facility at both intake points.

"Together, these measures executed in earnest should help in protecting the water quality of the Meghna River for Dhaka's sustainable water supply," the report said.