This study analyzes a concrete dam using Abaqus software at different water storage levels (60m, 70m, and 80m). The dam sections are designed based on these levels using approved equations by the United States Bureau of Reclamation. Static and dynamic forces, including seismic components, are calculated for worst-case scenarios. The analysis considers cases with and without galleries, varying the dam base width. Stresses (vertical, shear, and main) are calculated and presented as curves for comparison. The study examines the impact of reservoir water levels, additional base parts, and galleries on dam stability. Findings show that galleries significantly affect stress distribution, causing stress concentrations near openings. Normal stress is uniform except at the gallery, where it decreases. Maximum water storage leads to slight increases in normal stress. Without a gallery, normal stress increases until a certain distance, then decreases towards the pre-toe region, with maximum stress at the toe. The length of the additional base has a limited effect on normal stress. The presence of a gallery affects principal stress distribution, with higher values near the toe region for higher storage levels. The shear stress distribution is more uniform without a gallery. These findings demonstrate the complex interaction of factors in concrete dam stress behavior. Proper consideration of these factors is crucial for design, analysis, and maintenance to ensure structural integrity and performance. Further analysis considering material properties, loading conditions, and dam geometry would enhance understanding and facilitate precise design and safety assessments.