Farakka Barrage (malda)

Farakka Barrage is a barrage across the Ganges River, located in the Indian state of West Bengal, roughly 10 kilometres (6.2 mi) from the border with Bangladesh near Chapai Nawabganj District. Construction was started in 1960 and completed in 1974. The barrage was built to divert the Ganges River water into the Hooghly River during the dry season, from January to June, in order to flush out the accumulating silt which in the 1950s and 1960s was a problem at the major port of Kolkata on the Hooghly River. One of the important thing to note here is that the river divides Murshidabad and Malda districts of West Bengal. 

Bangladesh and India have had many debates about how the Farakka Barrage cuts off Bangladesh's water supply. Also in Bangladesh, the diversion has raised salinity levels, contaminated fisheries, hindered navigation, and posed a threat to water quality and public health. Lower levels of soil moisture along with increased salinity have also led to desertification. 
This is the longest barrage in the world[citation and has recently been entered into the Guinness Book of World Records. The barrage was constructed by the Hindustan Construction Company Limited. It has 123 gates and it serves water to the Farakka super thermal power station(NTPC Farakka).