Study on Maintenance Dredging for Navigable Depth Assurance in the Macro-tidal Hooghly Estuary

Abstract

Hooghly Estuary is a tide-dominated estuary in the east coast of India, experiencing heavy siltation in the navigation channel. This frequent siltation affects the movement of vessels, thus, hampering the efficiency of the port. The quantity of siltation is related to the physical and environmental conditions and the geometric configuration of the entrance as well as the navigation channels. This study aims at investigating the possibility of smooth navigable channel to the Haldia Dock Complex with a minimum quantity of maintenance dredging. The monitoring of the channel through bathymetry survey at regular intervals has been carried out. The filed survey involved identification of the zones of siltation, changes in the depth and estimation of sediment volumes at 10 different sections along the Eden bar. It was found in the study that the siltation depth varies between the spring and neap tide periods due to the variation in the tidal currents. From the field monitoring surveys, it is found that there is predominant erosion from neap-to-spring tidal cycle. These aspects are brought out in the manuscript along with the stability details of the Eden channel, throughout the year.