The Asian Development Bank (ADB) has approved $0.5 million in grant assistance for supporting the Bangladesh government's efforts to restore severely degraded waterbodies in Dhaka for managing watershed sustainably, says a press release.
"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," said ADB Bangladesh Country Director Manmohan Parkash.
"Recharging aquifers, restoring waterbodies, curbing surface water pollution, and increasing water retention area as well as flood-flow zones are critical to sustaining Dhaka city."
Appreciating the government's recent initiatives to revitalise waterbodies and rivers, Parkash said, "The grant assistance will provide policy options and innovative solutions, including new technologies and methods for the recovery and restoration of encroached waterbodies, their regular maintenance, and proper enforcement of laws – all of which are essential for waterbodies to be sustainable."
Considering both surface water quality and groundwater supply augmentation, the ADB assistance will help identify the policy gaps and suggest measures in the Dhaka watershed.
The policy analysis would bridge the capability gaps, apply best practices, and foster innovative solutions for the restoration of waterbodies with a focus on sustainable urban water supply challenges, which will be utilised in the design of the ensuing projects in the water supply sector.
It will support the preparation of a comprehensive water quality monitoring plan, including measures for restoration of waterbodies in the 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 the aquifer artificially.
The assistance project will assess supply augmentation potentials of available surface waterbodies – which 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 waterbodies, 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 urbanisation over the past few decades, the lakes and rivers of 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 two million cubic metres of untreated wastewater from 7,000 industries, 200 million litres of untreated municipal sewage, and improper disposal of 4,000 tonnes of solid waste from the two city corporations every day.
As a result, surface waterbodies have highly degraded and been filled with solid waste. The natural drainage system has also collapsed due to the illegal encroachment of 43 of the 65 major drainage canals, rivers, and ponds.
Dhaka city extracts 87% of its water supply from groundwater aquifers. Increased dependency on groundwater has led to a rapid fall of groundwater table by two to three metres per year, putting the city at the risk of subsidence.
Experts have suggested that to make 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.
The ADB is committed to achieving a prosperous, inclusive, resilient, and sustainable Asia and the Pacific, while sustaining its efforts to eradicate extreme poverty.
Established in 1966, it is owned by 68 members – 49 from the region.