The presence of sediment deposition and erosion in the Nun River significantly impacts water quality. While sediment deposition fosters habitats for aquatic life, excessive sediment can lead to pollution and turbid water, hampering photosynthesis and endangering organisms. Conversely, insufficient sediment diminishes habitat availability for bottom-dwelling organisms. This study aims to model sediment yield and river bank erosion in the Nun River Basin. For sediment yield modeling, twenty-one core samples were gathered from three stations at depths ranging from 5 to 35 meters using Uwitec Triple sediment cutter. These samples underwent laboratory processing for sediment particle size analysis and textural examination. The activity of excess Pb-210 atmospheric deposition was assessed with an alpha spectrophotometer to determine sediment age using Goldberg's constant flux model. This model assumes a constant 210Pb flux to sediment over time with variable sedimentation rates. Results from the Pb-210 sediment dating model indicated a consistent decrease in excess Pb-210 concentration with increasing depth. Sediment accumulation rates remained stable until 1990, where a significant increase 0.023 g/cm2 .y-1 in 1970s to 0.16 g/cm2 .y-1 in 2002 was observed, possibly due to flood events in 1987, 1991, and 1994. Sediment accumulation rates fluctuated until 2016, with the highest rate of 0.516 cm y-1 recorded in 2013. Extrapolating from the model, a constant 40% annual increase in sedimentation rate could lead to significant sedimentation rate of 4.23 cm y-1 by 2030, potentially resulting in floods in the Nun River vicinity.