Siltation at Farakka Barrage in River Ganga

“Dams Has Reduced The flow Of Rivers in Lower Plains” – Nitish Kumar

Siltation in River Ganga is the major problem of floods in Bihar and West Bengal every year. Cause of increase in siltation are Dams and Barrages which should be banned.Farakka Barrage was made to divert water of the Ganga River to Hooghly. The Hooghly River flows near Kolkata. It became dry many times during the year because water of the Ganga wholly flowed to Bangladesh through the Padma River. The water is being diverted to Hooghly from Farakka by a feeder canal. The below picture shows the diversion of water from Farakka Barrage into the Feeder Canal.

diversion of water from farakka barrage

Secondly this picture below shows the larger area showing flow of the water through the Feeder canal into the Hooghly and onwards to Kolkata.

flow of water through feeder canal

The level of feeder canal is 10 meters higher than the level of the Ganga. it was necessary to raise the level of water in the Ganga by 10 meters to put the water in the Feeder Canal. The Farakka Barrage was made to raise this level of water. By doing so, a pond has been built up to 50 km behind the barrage.

We give photo of the Farakka Barrage below. One can see the brown cultured water carrying heavy sediment load stagnant behind the barrage.

Farrakka Barrage at Bihar

The river is not able to move at her natural velocity due to the deposition of sediments in her bed.

In this lake, the water velocity is low due to which the sediment brought by the river is being deposited in the pond. This leads to slowing of the flow of the river and sediments are deposited many hundred kilometers upstream. We give photos of such silt deposition between Farakka and Patna.

slit deposition between farakka and patna

Below are the islands shows that the sediments are getting deposited.

sediment deposit on river

The Farakka Barrage Project dredges the river on one side to increase the flow. This leads to the water of the river flowing in that dredged channel and thereby increasing the erosion on the edges. We give below photo of erosion of the banks by the Ganga on upstream left bank. One can see the embankment made of stone in the backdrop. The river has cut into the land leaving the embankment.

Erosion of banks by River Ganga

Keeping this problem in mind in the past, Bihar Chief Minister Shri Nitish Kumar has demanded to removal of Farakka dam.

There is a need to make a fresh assessment of Farakka. As mentioned above, the level of the Feeder Canal is 10 meters above the surface of Ganga due to which the level of the Ganga has also been raised by 10 meters. For this reason the pond behind the barrage has been made and the erosion is taking place. One solution over this problem may be that instead of putting the Ganga water in Hooghly with feeder canal, it should be put directly in Hooghly. In the photo below we can see that a stream of Ganga flows south before the Ganges enters Bangladesh. From this stream the Hooghly comes out near Fatelapur. Here the level of Hooghly level is only 3 meters above the Ganges. Therefore, if water of the Ganges is put in Hooghly at Fatelapur it will have to be raised by only 3 meters.

Barrage can be constructed with undersluices

The new barrage at Fatelapur can be made with under sluices. Then no pond will be created behind barrage to push water into Hooghly. The gates of the Farakka barrage can be removed and it can be sued as a bridge.

We request Prime Minister Narendra Modi and Chief Minister Nitish Kumar to order a fresh study of the alternatives to the Farakka Barrage so that Ganga can flow freely to Kolkata and Gangasagar.