Climate change, coupled with rising temperatures, has increased evaporation rates and reduced precipitation levels. Consequently, the Caspian Sea (CS) faces the risk of declining water levels, posing numerous challenges to critical sectors, including shipping, fisheries, wetland conservation, and the protection of designated areas. Astara port, located in the southwestern region of Iran’s Caspian Sea, is particularly affected by this decline in water levels. The reduction can have both direct and indirect effects on sedimentation within and around the harbor basin. Firstly, it may lead to a decrease in the depth of the harbor and navigational channels. Additionally, it can influence the volume of sedimentation occurring in the vicinity. The objective of this study is to investigate the relationship between declining water levels and sedimentation rates in Astara harbor. The findings indicate that a 1 m decrease in water level results in approximately a 50% increase in sediment volume within the channel.