Abstract : The major rivers of Central Asia (Amu Darya, Syr Darya and Zerafshan) are turbid watercourses. Thus many man-made water reservoirs are affected by high sedimentation rates. It is of strategic importance to rationally quantify available water resources in existing reservoirs to ensure a guaranteed water supply to the different water users. Recent drought years and physical deterioration of hydraulic structures urged authorities to re-estimate the water availability in reservoirs of Uzbekistan for the sustainable use of the scarce water resources and safe operation of hydraulic infrastructure. This paper presents the results after the application of a geostatistical approach to assess the water resources availability in the Akdarya reservoir of Uzbekistan. The geostatistical approach creates digital surfaces that represent relatively accurate reservoir bottom conditions and support automated reservoir volumes and surface areas calculations. This in turn significantly reduces time, work load and financial burdens for sedimentation survey projects.