Lajanuri reservoir is an engineering-hydrotechnical structure in Tsageri municipality, created by a high arch dam in the narrow valley of the lower Lajanuri River, near the village of Surmushi. It is oval in shape: length 3.2 km, greatest width 1 km, average width 0.5 km. Greatest depth 70 m, average depth 30 m, area 1.6 km², volume 50 million m³. The reservoir is fed by the Lajanuri, Kheleshurisghele, Liamghvrie and Usakheloghele rivers, and by water brought by canal from the Tskhenistskali. It provides daily regulation and supplies the Lajanuri hydroelectric station.