The government has unveiled a Tk 32,554 crore plan to strengthen Dhaka’s water security by developing five large reservoirs around the capital to reduce dependence on rapidly depleting groundwater.

Prepared by the Institute of Water Modelling, the proposal recommends converting selected wetlands into artificial reservoirs capable of supplying 445 million litres of treated surface water per day.

The initiative follows an Executive Committee of the National Economic Council decision on April 26, 2026, directing the authorities to assess Dhaka’s future water demand and explore rainwater harvesting and water reuse.

The plan was presented at the Ecnec meeting on Wednesday.

According to the IWM report, the projects will require Tk 32,554 crore for land acquisition and infrastructure.

Dhaka currently needs about 3.13 billion litres of water a day, while Dhaka Wasa produces around 3.0 billion litres, leaving a shortfall of about 130 million litres.

Nearly 77 percent of the city’s water comes from 1,388 deep tube wells, causing groundwater levels to fall by 2-3 metres a year. Demand is projected to rise to 3.3 billion litres per day by 2030 and 5.5 billion litres by 2050.

After assessing seven wetlands within 35 kilometres of Dhaka, IWM identified five suitable sites.

The largest project, the Belai Beel Reservoir in Gazipur, would cover 2,250 hectares, store 95 billion litres of water and supply 260 million litres per day at an estimated cost of Tk 9,270 crore.

The report describes it as the most cost-effective option but recommends further studies on its possible impact on biodiversity and local fishing communities.

The Ashulia Reservoir, proposed on the Turag floodplain beside Uttara Phase-3, would supply 150 million litres per day from a 1,000-hectare reservoir at a cost of Tk 13,167 crore.

As the site lies in a flood-flow zone and the Turag is an Ecologically Critical Area, the report recommends strict environmental safeguards and advanced treatment to address dry-season pollution.

The Moksh Beel Reservoir on the Bangshi river in Kaliakair would cover 640 hectares and supply 60 million litres per day at a cost of Tk 5,549 crore.

Although its distance from Dhaka may raise transmission costs, it could become an important source for Gazipur City Corporation if industrial pollution is controlled.

The Uttarkhan Reservoir, proposed on the Balu floodplain, would supply 20 million litres per day from a 230-hectare reservoir at an estimated cost of Tk 2,289 crore.

However, the site falls within a primary flood-flow zone under Rajuk’s Detailed Area Plan, while pollution in the Balu would make treatment difficult.

The Dasherkandi Reservoir in eastern Dhaka would cover 253 hectares and supply 15 million litres per day at a cost of Tk 2,279 crore.

Located near the Dasherkandi Sewage Treatment Plant, it could store rainwater and treated wastewater for industrial and other non-potable uses, reducing demand for drinking water.

Although more expensive than existing river-based treatment projects, IWM said the reservoirs would diversify Dhaka’s water sources, improve climate resilience, provide emergency storage and reduce reliance on groundwater.

Existing projects such as Gandharbpur Phase I and Sayedabad Phase III require Tk 200-230 crore per 10 million litres of daily supply, compared with Tk 356 crore for Belai Beel and Tk 1,519 crore for Dasherkandi.

The report also said the Kallyanpur and Goran-Chatbari retention ponds are unsuitable for drinking water because of poor water quality and limited storage.

It added that Dhaka’s surrounding rivers, including the Buriganga, Turag, Balu, Shitalakshya, Dhaleshwari and Tongi Khal, remain too polluted for cost-effective drinking water production, underscoring the need for stronger pollution control.

Urban planners welcomed the proposal to conserve wetlands but urged caution over using them as major drinking water sources.

Bangladesh Paribesh Andolon Vice-President Iqbal Habib said Bangladesh adopted a similar policy in 1997 but failed to implement it through an integrated approach.

He said the new initiative should incorporate lessons from previous efforts, stressing that institutional coordination is essential for both reservoir conservation and effective implementation.

Adil Mohammed Khan, former president of Bangladesh Institute of Planners, said the reservoirs should be conserved regardless of whether they are eventually used for water supply.

He noted that, unlike rivers, reservoirs lack continuous inflow, making excessive water abstraction a concern requiring detailed technical studies.

Khan also said the DAP identifies around 60 other reservoirs and wetlands for protection.

While prioritising the proposed five is reasonable, he warned that failing to conserve the rest would weaken Dhaka’s natural drainage system and increase flood risks.