Bangladesh News

Groundwater-based irrigation system is experiencing difficulties in different parts of the country as shallow aquifer level is getting out of reach due to fast depletion of groundwater table.

Shallow tube-wells (STWs) now cannot draw water for about 46 percent irrigated cropland during dry season thanks to current level of groundwater declination, says data from Survey and Monitoring of Groundwater project and groundwater zoning map.

STWs can draw groundwater for irrigation within a depth of 2-7 metres.

“The problem persists mainly in the dry season when farmers irrigate their cropland,” said Khondakar Fazle Hasan, chief geologist of Bangladesh Agriculture Development Corporation (BADC).

Asked how farmers do the irrigation if STWs don’t work, he said they make a pit five to six feet bellow the surface and put the shallow pump there to draw groundwater.

According to 2006-07 irrigation survey report of the government, around 10 million farmers have overwhelming dependence on STWs for almost 70 percent of 47.8 lakh hectares of irrigated cropland in the last Rabi season.

The groundwater zoning map of BADC prepared in 2006 shows that a record high of 78 percent irrigated cropland in Pabna has become critical for STW operation.

The level is 75 percent in Comilla, 60 percent in Kustia and Naogaon, 55 percent in Mymensingh and Cox’s Bazar, 50 percent in Joypurhat, 49 percent in Chittagong, 45 percent in Bogra and Rajbari and 30 percent in Jhenidah, Netrakona, Gazipur and Narayanganj.

In 62 upazilas, the groundwater level goes down more than seven metres. In 14 of these upazilas from the country’s central and northern parts, water level goes over 11 metres down in dry season, says the quarterly monitoring report of Survey and Monitoring Project for Development of Minor Irrigation.

Besides, farmers are being unable to draw water by STWs for 28 percent of the land in Sherpur, 20 percent in Jamalpur and Tangail, 18 percent in Natore, 16 percent in Manikganj, 15 percent in Dhaka, Narsingdi and Sirajganj, and 10 percent in Rajshahi, Chapainawabganj, Kishoreganj and Munsiganj.

Experts say regulation of water flow in the Ganges at Farakka point by India has caused a reduction of dry season flow. Decreased flow in the Padma and its distributaries has affected the pump irrigation, they add.