<![CDATA[The Leuwikeris Dam, which began operating in 2024, serves the functions of flood control, irrigation water supply, and raw water provision. This embankment-type dam is monitored using geotechnical instrumentation to ensure safety during the initial reservoir filling. This study aims to evaluate the stability of the Leuwikeris Dam based on geotechnical instrumentation data, analyze the relationship between rising reservoir water levels and the dam's response, and identify the geotechnical factors influencing instrument readings. The analysis was conducted using geotechnical instrumentation monitoring data collected from the post-construction period through the initial reservoir filling. The instruments analyzed included piezometers, inclinometers, multilayer settlement gauges, and shear markers. Pore water pressure data were used to model the phreatic line and perform dam stability analysis, while deformation data were used to evaluate the dam embankment's response to changes in loading caused by rising reservoir water levels. The analysis results indicate that the Leuwikeris Dam remained safe and stable throughout the initial reservoir filling. The minimum stability factor was 1.21 under the Operating Basis Earthquake (OBE) condition, exceeding the minimum required value of 1.2. Under the Maximum Design Earthquake (MDE) condition, the permanent displacement analysis showed a maximum displacement of 354.84 cm, which is below the allowable limit of 375 cm. The maximum measured horizontal movement was 63.48 mm toward the downstream side. The maximum settlement reached 2.92 m at the center of the embankment and 1.47 m near the dam crest (1.7% of the dam height), which falls within the normal range according to the USBR (2011) criteria. Overall, the monitoring results demonstrate that the dam exhibited consistent behavior and satisfied the safety criteria throughout the initial reservoir filling.Keywords: The Leuwikeris Dam, geotechnical instrumentation, stability, the dam's response]]>
