High Barind running out of water: New study identifies water stress areas of the region

Due to decades of over-extraction, more than 40 percent of unions in High Barind, an already water-stressed region of Bangladesh, are experiencing severe depletion of groundwater, says a recent study.

While climate change is impacting on the aquifer recharge, the study says, the depleting areas, spread across three districts of Rajshahi, Chapainawabganj, and Naogaon, are expanding, limiting people’s access to water for both drinking and irrigation.

Hired by the Water Resources Planning Organisation (WARPO), the Institute of Water Modeling (IWM) conducted the study titled 'Hydrological investigation and modeling of the state of the surface and groundwater resources in the High Barind region’.

Beginning in 2018, the study works completed with WARPO approving the draft final report on June 25, 2023, says Md Rezaul Maksud Jahedi, director general of WARPO.

The final report is likely to be published in August, he said.


The figure shows the dry season groundwater situation in the High Barind

Financed jointly by the Government of Bangladesh and the Swiss Agency for Development and Cooperation (SDC), the study suggested alternative surface water and the promotion of conjunctive use of groundwater and surface water in the affected areas.


The study, the first of its kind in the country, identifies actions to preserve water resources of the region, a recognized hotspot in the Delta Plan 2100, says Prof Chowdhury Sarwar Jahan, one of the key experts reviewing the study.

“Life in the Barind is written with water. People’s challenges there may become unbearable unless the depleting resources are not well managed immediately,” he said.

 
The figure shows groundwater situations in the months of May and November.

According to the study, the pre-monsoon groundwater table depth of the region was already deeper in 1985 and 1990, when groundwater uses were limited to household needs.

At that time, the depth was around eight meters in most areas, with a maximum depth of 21 meters at a few spots of Gomostapur and Tanore upazilas.

Due to over-extraction for drinking, irrigation, pisciculture, and industrial uses by 2010, the average depth declined beyond 15 meters, with a maximum of 25 meters at additional pockets of Sapahar, Nachol, and Niamatpur upazilas.

In 2021, the average decline increased below 18 meters in an extended area. In some spots, the decline was even more severe, with the water table dropping as much as 46.87 meters in Gomostapur of Chapainawabganj.

Other than over-extraction, climate change is affecting the aquifer recharge by decreasing the rainfall to as low as 1200mm from 2000mm and increasing evaporation. The thick clay layers of the region make the replenishment difficult, the study says.



Identifying Water Stress Areas

The study calculated actual recharge and safe yield levels of aquifers to identify the union-wise water stress conditions of the region of 25 upazilas. [An aquifer is a body of rock or sediment that holds groundwater. Groundwater is the word used to describe precipitation that has infiltrated the soil beyond the surface and collected in empty spaces underground. Groundwater recharge is a hydrologic process, where water moves downward from surface water to groundwater.]


The figure shows Water Stress areas of Rajshahi.


At least 87 unions, which is 40.65 percent of the total 214 unions in the region were placed in the top two critical categories of very high, and high water stress areas.

In these unions, the water level of the previous monsoon declines in the next monsoon, the study says.

 

The figure shows Water Stress Areas of Chapainawabganj.  

The entire Porsha (six unions) and Nachol (four unions) upazilas fall under the category of very high water stress areas where depletion was at its worst with no or little aquifer recharge.

This very high category also includes 37 other unions of nine upazilas including Godagari, Tanore, Gomostapur, Niamatpur, and Sapahar in the three districts.


The figure shows Water Stress areas of Naogaon.

Moderate water stress areas include 65 unions where the water resources are under pressure.

On a somewhat positive note, the study says the region has only 28 unions under ‘low’ and 34 under ‘very low water stress’ categories where a water crisis is yet to occur.

Aquifer zones

The study shows the region mostly has either single or double aquifers while a few areas at the outer areas of the Barind tract have multiple aquifers.

The study found no aquifer at the drilling depth of 445 meters at Tetulia, Chaor and Ganguria unions under Porsha and Sapahar upazilas.

One thin aquifer with thickness varying between 6 to 16 meters at 426 meters depth is the only water source for the Badhair union of Tanore, Nachol, parts of Chapainawabganj Sadar, and Gomastapur upazilas.

The study finds bicarbonate, iron, and manganese presence exceeding the permissible standards in some groundwater samples while arsenic contamination only in the Ranihati union.

The study proposed for excavation of surface water reservoirs, emphasising on immediate re-excavation of existing beels and ponds to address the issues right away.

It recommended bolstering crop diversification processes as an alternative to the water-consuming Boro crops at worst affected areas.

The study also advises the implementation of artificial recharge of groundwater to replenish and maintain the aquifers in the region.

Also, read

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Groundwater abuse takes toll on Barind

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