Chittagong braces for worst water woes

The Chittagong Water Supply and Sewerage Authority or WASA — the only one of its kind in the Bangladesh’s premier port city – in a recent notice, disseminated through the media, warned against drinking supply water due to salinity. This is nothing new as this announcement comes almost every year, especially during dry seasons.

The question the situation begs: why salinity is still an issue in supply water even despite the WASA building several large water treatment plants at a cost of Bangladesh Taka 100 billion.  The reason for the water still remaining undrinkable evolves in a labyrinth.

To address the growing demand, the WASA wants to implement more projects worth Taka 300 billion. But will the move truly resolve this perennial problem?

Lying along the coastline of the southeastern Bangladesh, Chittagong has water almost everywhere within its territory. This city of over six million people, however, suffers from an acute shortage of water – from drinking water to the water used in industrial operations. The Chittagong WASA mainly supplies the city with water from the Karnaphuli and Halda rivers.

It should be noted that several of the port city’s top conglomerates are now at fight with each other in a bid to take control of hilly springs in Sitakunda upazila, one of the largest heavy industry zones of Bangladesh that is situated just on the outskirts of the city.  

The state-owned Chittagong Urea Fertiliser Limited (CUFL) has been forced to halt production for two – sometimes even more – months every year due to excessive salinity in the Karnaphuli River water, which is their key raw material.

According to the WASA and the CUFL, who measure the salinity of the Karnaphuli and the Halda rivers every few hours, have stated that climate change has rendered the water of these rivers unfit for use.

During the dry season, when the rivers do not receive enough upstream water, the inland flow pulls from the Bay of Bengal. In the last 33 years, the salinity of Karnaphuli has increased by almost 3,000 times – jumping from 5 ppm (parts per million) to a staggering 6,800 ppm.

Meanwhile, in 2004, the highest recorded salinity in the Halda River stood at 90 ppm, which later leaped to 11,000 ppm after Cyclone Yaas in 2021. According to the WASA, when the salinity of water exceeds 300 ppm, it becomes unfit for drinking.

Aiming at fulfilling the demand and the needs of people, the WASA has been trying to mitigate the crisis to some extent by utilising underground water in the supply. This effort, too, is getting derailed due to too much salinity in the Karnaphuli and Halda rivers.

WASA Chief Engineer Maqsud Alam said, “Because of the low water flow from upstream Karnaphuli, sea water is entering the river. We found a maximum of 1,700 ppm salinity in Halda water at the Mohra plant.

“According to the Environment Protection Act, water can only be considered drinkable if the salinity level stays between 150 mg and 400 mg per litre. We are mixing groundwater with river water to bring down the salinity level below 400 ppm, and supplying the port city consumers.”

The demand for fresh water in the port city is increasing by 50mld (million litter daily) every year. The WASA projects that the demand will reach 63 million litres by 2032 and 122 million liters by 2041.

Groundwater level decreasing rapidly

The groundwater level in the second largest city of Bangladesh dropped by 20 meters in the last 40 years, mainly due to over-extraction, leaving hundreds of tube wells unusable. Many households and industries are now in serious trouble, with agriculture in the adjacent upazilas (sub-districts) under growing threat.   

Because of the significant decline in the groundwater level, scientists believe there is an impending crisis of natural and humanitarian disasters in the region. The situation will spiral out of control in the coming days if the excessive exploitation of groundwater is not reined in.

Climate scientists add that along with the rising sea level, salinity is also increasing in the seawater.

Prof Dr Sarwar Iqbal of the Department of Geography and Environmental Science at Chittagong University said, “The temperature in Chittagong division rose by 0.2 degrees in the last 20 years, but the average temperature in Chittagong district jumped by 0.4 degrees.

“Climate change has altered the pattern of rainfall, while the rise in sea level has increased salinity in the coastal regions. This in turn has forced industries and residents to extract more groundwater, causing groundwater levels to drop rapidly.”

Bleak findings 

A case study into the PHP Float Grass Factory at Sitakunda shows that they are now covering their daily water demand for one million litres by harvesting rainwater, mountain springs, and bringing in water from the Feni River through voucher.

This has significantly increased their production costs.

Addressing this issue, PHP Family Vice Chairman Mohammed Mohsin said, “The groundwater level in our region has witnessed a significant decline, triggering an acute shortage of water. 

“We are collecting rainwater, utilizing three nearby mountain springs, and bringing in water from faraway Feni River. This barely covers the daily demand of our factory.”

Data from the Department of Public Health Engineering (DPHE) shows that 12,785 tubewells installed by the government, and 30,000 tubewells installed privately, in 16 upazilas of Chittagong have become unusable in the last ten years.

DPHE Superintendent Engineer (Chittagong Circle) Jahir Uddin Dewan blamed climate change, presence of arsenic and salinity in groundwater, and increase in salinity in river water for the city’s water crisis.

According to the Bangladesh Water Development Board (BPDB) Ground Water Hydrology division, among the more than seven and a half million residents of the district, nearly million are facing an acute water shortage.

BPDB Ground Water Hydrology division Director Dr Anwar Zahid said, “After Cyclone Sidr struck Bangladesh in 2007, the salinity in rivers began to increase rapidly, causing the groundwater withdrawal by industries to go up significantly.

“With the increase in the number of industries, the demand for water has skyrocketed. Moreover, almost every village home has installed tube wells and submersible pumps. Groundwater was previously only used for drinking and now it is used for daily use.”

He continued, “If we are unable to find an alternative source of water for industrial use, the industrial units will continue to increase their use of groundwater in the coming days. This in turn will further worsen the ongoing water shortage in this region.”

69% of Chittagong hit by tidewater

Data from the Center for Environmental and Geographic Information Services (CEGIS) shows that nearly 69% of Chittagong gets inundated by tidewater during different timeframes, and the saline sea water also damages the port city infrastructure and triggers a shortage of fresh water.

Agrabad CDA Residential Area in the city is one of the key victims to this phenomenon, as roads and other structures in the area get inundated by tidewater two times a day for nearly three hours. The ground floors of many buildings also become waterlogged.

Thousands of residents in the area become practically trapped in water. For at least six months a year, the residents adjust their day-to-day schedule with low and high tides. Once a residential area for the elite, Agrabad CDA is now gradually losing its residents. 

Many had invested heavily in building homes in this area, but this venture has now turned into a money sink.

The situation worsens during new moons, full moons, and natural disasters, when the tidewater level rises by one or two meters above the usual. So, this modern residential area built on 82.18 acres of land is now mostly abandoned.

The rising water levels in the Karnaphuli River, which connects to the Bay of Bengal, have forced many residents in the area to evacuate their homes due to 2.51 meters of tidewater.

Many Agrabad residents have already moved to residential areas in Chandgaon and Khulshi, or are planning to do so soon.

Experts say that Chittagong city is vulnerable to floods triggered by tidewater. So, this city faces its unique challenge to adapt to global climate change.

Shrinking rainfall, drying reservoirs

According to the Bangladesh Meteorological Department, Sitakunda recorded an average rainfall of 141mm during the month of March in the 1990s. But during the same month from 2013 to 2023, the average rainfall stood at only 33.72mm across the same region.

At the beginning of summer, April recorded an average rainfall of 161.9mm in the 90s — but the average rainfall in the same month between 2013 and 2023 dropped to 139.81mm.

Rain at regular intervals used to be the norm. But nowadays, frequent torrential downpours at times, and no rain at other times, are complicating the weather cycle in this region – a direct impact of climate change-related complications.

Professor Dr Sarwar Iqbal of the Department of Geography and Environmental Science at Chittagong University blamed the gradual decline in rainfall in March and April on climate change.

Echoing the same, Chittagong University Institute of Forestry and Environmental Science Director Prof Dr Akhter Hossain said, “The decline in average rainfall and prolonged dry season is behind the drying up of mountain springs, lakes, and flat land water reservoirs.

“This phenomenon is behind the water shortage on surface level and plays a key role in the gradual drop in groundwater level. Under such circumstances, the already acute shortage of water is worsening day by day.”

The researcher fears the crisis may intensify in the coming days.

There is no alternative to sustainable planning to address this problem, he said, adding, Bangladesh must also work on increasing the number and capacity of water reservoirs and focus on preserving water resources.

Shamsuddin Illius, the author of this article, is a journalist.