Ukai Reservoir witnessed flood incidents in 2006, 2013 and 2019, causing significant damage to property and infrastructure. The objective is to analyse the spatial-temporal change in inundation of Reservoir & soil loss. Normalized Difference Water Index (NDWI), Modified Normalized Difference Water Index (MNDWI), Universal Soil Loss Equation, and Land Use Land Cover (LULC) were applied. Landsat-8 data was collected from 2013 to 2020 for pre & post-monsoon periods. Decreasing water inundation area trend from 2015 to 2016 observed, possibly due to excess irrigation, power generation. 2016 faced increased water spread area, could be because of heavy precipitation in the upstream catchment. A high Rainfall erosivity factor (96.27 to 1427.58) indicates intense rainfall, which denotes a more remarkable ability of an area to detach and transport soil particles. High Soil Erodibility Factor (0.05 to 0.34), depict higher erodibility. The Topographic Factor (0 to 146.01), means more erosion occurs in steeper areas. The highest predicted annual soil loss was in the moderately high erosion category. Low Crop Management factor (0 to 1) denotes loss. Overall soil loss in this area is increasing, and need soil conservation. The Average Annual soil loss factor (26.64 to 44.05) depicts increase in soil loss. LULC analysis shows agriculture (69.77% in 2018) and barren land (24.38% in 2020) are the two predominant classes. The variation in the area was directed by rainfall in the post-monsoon time, excess irrigation, and electricity generation during the pre-monsoon time.