Instrumentation and monitoring of real-time data during the construction of any civil engineering project not only help in the successful execution of the project but can also account for the safety of the structure and the workforce during construction as well as during the life span of the project. Moreover, the instrumentation data is an indicator of structural response to various loads and stresses. Instruments must be installed timely at critical locations to get meaningful data. The delay in installation due to any reason can lead to hazardous situations. Because of numerous benefits of structural safety, human life safety, construction economics, legal support, and hazard prediction. Geotechnical instrumentation has proved its importance over recent years and gained popularity. In the present case study, geotechnical instrumentation of the Vyasi Dam hydroelectric project, a runoff of the river scheme on river Yamuna, consisting of an 86.0 m high concrete gravity dam and a surface powerhouse of 120 MW near Dakpathar, Dehradun, Uttrakhand, has been discussed. There are a total of 13 Blocks in the dam, out of which only 3 Blocks have instrumented with a total of 313 instruments namely Block 4 (left abutment, non-overflow section), Block 8 (central block, overflow section), and Block 12 (right abutment, non-overflow section), respectively. These instruments include stress meters, no-stress strain meters, strain meters, temperature meters, joint meters, pore pressure meters, uplift pressure meters, tilt meters, load cells in abutment galleries, etc. at different elevations of the dam to measure stress, strain, temperature, movement, pressure, and water flow at the dam and its appurtenant structures. Apart from these instruments, Normal and Inverted plumb lines have also been installed to monitor deformation along and across the dam axis during the first filling and operational stages. Seepage measurement devices (V-Notches) at various elevations and locations for identification of sections with abnormal seepage discharge are also in place. In the present study, it is proposed to compare the above parameters during the construction phase, filling, and post-filling phase, and to correlate these parameters with changes in water level in the reservoir.