The Asian Development Bank (ADB) has approved $0.5 million in grant to support the government’s efforts to restore severely degraded waterbodies in Dhaka for managing watershed sustainably.
Considering both surface water quality and groundwater supply augmentation, the ADB assistance will help identify the policy gaps and suggest measures in Dhaka watershed, according to an ADB release.
The policy analysis would bridge the capability gaps, apply best practices, and foster innovative solutions for restoration of water bodies with a focus on sustainable urban water supply challenges, which will be utilized in the design of the ensuing projects in the water supply sector.
It will support preparation of a comprehensive water quality monitoring plan including measures for restoration of water bodies in Dhaka watershed and develop an online water quality monitoring mechanism.
The assistance will help assess the storage capacity of aquifers and threats of pollution from endogenous and exogenous processes, analyse groundwater reserve and recovery status, explore suitable locations and techniques for aquifer recharge, and prepare a comprehensive plan for recharging aquifer artificially.
The assistance project will assess supply augmentation potentials of available surface water bodies that are partially or entirely within Dhaka City by detailed mapping, and listing of waterbodies with restoration potential focusing on all season storage enhancement, groundwater recharge, and enhanced ecosystem services.
Pollution mapping, measuring pollution levels of water bodies, identification and evaluation of suitable restoration measures including technical and nature-based solutions for pollution prevention and reduction, and flow augmentation will also be taken up.
Due to high population growth (from 0.1 million in 1906 to 20.2 million in 2020) and unplanned urbanization over the past few decades, the lakes and rivers of the Dhaka city have been severely degraded and the groundwater aquifer has rapidly depleted.
Water management practices have been environmentally unfriendly and unsustainable because of direct discharge of 2 million cubic meters of untreated wastewater from 7,000 industries, 200 million litres of untreated municipal sewage, and improper disposal of 4,000 metric tons of solid waste from the two city corporations every day, said the release.
As a result, surface water bodies have been highly degraded and filled with solid waste.
The natural drainage system has also collapsed due to illegal encroachment of 43 of the 65 major drainage canals, rivers, and ponds.
Dhaka City extracts 87 per cent of its water supply from groundwater aquifers. Increased dependency on groundwater has led to a rapid fall of groundwater table by 2-3 meters per year, putting the city at the risk of subsidence.
Experts have suggested that to make the Dhaka City healthy, liveable, and resilient, it must conserve 5,737 acres of water retention area, 18,782 acres of canals and rivers, and 81,000 acres of flood-flow zones.
ADB Country Director Manmohan Parkash said Dhaka city needs a reliable, improved, sustainable, and climate-resilient water sourcing and supply system to ensure a healthier, and better-liveable city for the citizens.
“Recharging aquifer, restoring water bodies, curbing surface water pollution, and increasing water retention area as well as flood-flow zones are critical to sustain the Dhaka City,” he said.
Appreciating the government’s recent initiatives to revitalise waterbodies and rivers, Parkash said that the grant assistance will provide policy options, and innovative solutions, including new technologies and methods for the recovery and restoration of encroached waterbodies, its regular maintenance, and proper enforcement of laws--- all of which are essential for water bodies to be sustainable.
