The Barezoo dam on the Gholjogh River, a branch of the Atrak River with a catchment area of 491.7 km2, is located about 18 km north of Shirvan city in NE Iran. Landslides are an important natural hazard in the Atrak watershed and cause serious problems for the maintenance of the Barezoo reservoir. Landslide occurrence is controlled by lithology, slope of the terrain, and natural and human actions that may either add to the operating gravitational stresses or reduce the resistance to sliding of the soils forming the slope. The interaction between local geology and climatic conditions in this area has resulted in landforms with varying degrees of susceptibility to landsliding. Dammed watersheds in NE Iran experience numerous landslide and sedimentation problems. A quantitative approach based on a numerical rating scheme called the landslide hazard evaluation factor rating scheme was used to evaluate and describe landslides and their resultingsedimentation in the Gholjogh watershed.