Explain the following line,"Kolkata being a tidal port requires constant dredging of hoogly".

Kolkata is a tidal port which means it serves as a port during high tide when the water in the Hooghly rises. But with high tide, a lot of sediment is also deposited in the Hooghly. Hence, the river has to be periodically dredged to clear out the sediment. This ensures the depth of the river remains sufficient to allow large ships to enter the port.