Bathymetry or hydrographic surveying is used to measure and map the depths and shapes of underwater terrain. Presently, bathymetric survey data are typically gathered using acoustic-based devices, such as single or multi-beam echo sounding systems. Bathymetric survey work has been an integral part of the development of many bridges and marine projects, off-shore wind facilities around the globe, shoreline stabilization, engineering design, or infrastructure remediation, for flood inundation, scour and stabilization, water quality studies, waterfront facility inspections, habitat mapping, dam removals and environmental spills. Due to rainfall, snowmelt and erosion of river channels, the runoff from rivers within a catchment is continuously bringing down the sediments, which get deposited in the reservoir, leading to a reduction in its storage capacity. There are several methods available to find the depth of water, assess the sediment deposits into water and mitigate the sedimentation problem ranging from soil conservation measures to the mechanical removal of sediments. There are basically two approaches for measurement of sediments in the water. In direct methods, several instrumentations, such as Echo-sounding sonar systems are used, while, in indirect methods numerical modelling is carried out to assess the soil erosion and sediment yield from the catchment contributing to the reservoir. In both the methods, remote sensing, GPS (Global Positioning System) and GIS (Geographic Information System) are providing important data input, such as extent of water in a reservoir, land use and land cover types, shorelines, morphology of rivers, landforms, soil erosion, etc. This paper discusses the various direct and indirect methods used for measuring the waterbed as well as rate of sedimentation in reservoir/river/sea, including their usefulness. LiDAR systems, including the use of Autonomous Underwater Vehicles (AUVs) and Autonomous Surface Vehicles (ASVs) for sedimentations studies are also discussed.