Explanation:

Preserve and maintain Calcutta port 

Farakka Barrage Project with headquarters at Farakka in Murshidabad district of West Bengal is a subordinate office under the Union Ministry of Water Resources, River Development & Ganga Rejuvenation. The Farakka Barrage Project Authority was set up in 1961 with the mandate to execute and thereafter operate and maintain the Farakka Barrage Project Complex. Main objective of the Farakka Barrage Project complex is to divert adequate quantity of Ganga waters to Bhagirathi-Hoogly river system through 38.38 km long feeder canal for preservation and maintenance of Kolkata Port by improving the regime and navigability of the Bhagirathi-Hoogly river system.