Deep excavation is required for the construction of high-rise structures in urban contexts due to the proximity of many buildings. Nevertheless, substantial soil movement caused by these types of excavations can put surrounding buildings at risk. Soil stiffness and in situ, stress levels are two of the most important ground factors that affect the performance of deep excavation projects. As a retaining structure, secant pile walls are frequently used to sustain deep excavations, particularly in areas with a high water table. The purpose of this field study is to examine the behavior of full-scale, instrumented secant pile walls under different water levels. The data encompasses readings from pressure cells and wall movements and covers 300 days. In the analysis, different depths of water from 2 to 4.5 m below the ground surface are taken into account. The data analysis shows that the movements close to the wall bases were not enough to produce active pressures, and the measured earth pressures near the wall bases were in good agreement with the at-rest pressures. Changes in earth pressure were caused by variations in the water table level, and excavation activities reduced the lateral soil load on the walls by removing water. The result was a reduction in applied stresses and moments.