###### Abstract  
The Tiga Dam, a primary hydraulic structure in northern Nigeria, is subjected to intense hydrological stress during the rainy season, posing potential risks to its structural integrity. This study investigates the geotechnical properties and stability of the Tiga Dam in Kano State, Nigeria. Twelve soil samples from the downstream area were analyzed for specific gravity, grain size distribution, Arterberg limits, compaction parameters, permeability, and shear strength. The dam's stability was assessed using Plaxis 2D under various reservoir conditions. Soil erodibility was evaluated using the Revised Universal Soil Loss Equation (RUSLE), and a linear regression model with noise was developed to predict soil expansion rates. The results showed heterogeneous soil properties, with specific gravity ranging from 2.11 to 2.63 and permeability from 3.40 \(\times\) 10\({}^{-9}\) to 1.49 \(\times\) 10\({}^{-7}\) m/s. Stability analysis revealed factors of safety of 1.322, 1.006, 1.002, and 1.147 for high reservoir, rapid drawdown, slow drawdown, and low reservoir conditions, respectively. The RUSLE K factor ranged from 0.055 to 0.145, indicating low to moderate soil erodibility. The expansion rate model demonstrated high accuracy (R\({}^{2}\) = 0.989) in predicting seasonal and long-term soil expansion trends, with peak rates increasing from 16.94 mm/month in 2010-2013 to 19.45 mm/month in 2017-2020. This comprehensive analysis provides crucial insights into the Tiga Dam's geotechnical behavior, highlighting potential vulnerabilities and the need for targeted management strategies to ensure long-term stability and safety. oe 2024 14 6422. [[https://doi.org/10.3390/app1415642214](https://doi.org/10.3390/app1415642214)]([https://doi.org/10.3390/app1415642214](https://doi.org/10.3390/app1415642214)) 14 6422 1  
to erosive forces from rainfall, runoff, and fluctuating reservoir levels [9]. Factors such as soil composition, grain size distribution, plasticity characteristics, compaction, permeability, and shear strength are pivotal in determining the soil's susceptibility to erosion, deformation, and instability [10; 11; 12; 13; 14; 15; 16; 17; 18; 19]. Furthermore, seasonal variations and long-term environmental changes can significantly influence soil behavior, leading to phenomena such as expansion and contraction, which can impact the structural integrity of earth dams [20]. Understanding these temporal dynamics is essential for developing robust monitoring and maintenance protocols. The geotechnical behavior of earth dams and their foundations is a subject of extensive research, given the critical importance of ensuring structural stability and safety. Several studies have investigated the role of soil composition, physical properties, and environmental factors in influencing the performance of dam structures, but there are notable gaps in the existing literature [21; 22; 23]. While the studies provide a snapshot of soil properties, there is limited information on how these properties change over time, particularly in response to seasonal variations and long-term climatic changes. We adopted the Revised Universal Soil Loss Equation (RUSLE) to address some of these gaps for the geotechnical risk assessment of earth dams [24]. This innovative approach allows for a more comprehensive evaluation of soil erosion potential and its impact on dam stability. Additionally, we employed linear regression models with noise to analyze the complex relationships between soil properties and environmental factors [25]. The RUSLE adaptation involves modifying the equation's parameters better to suit the specific conditions of earth dam structures. This includes adjusting slope length and steepness, soil erodibility, and vegetation cover to reflect the unique characteristics of dam embankments and foundations. The modified RUSLE provides a quantitative assessment of potential soil loss, which is crucial for evaluating long-term dam stability.