H. karimi - Agriculture Faculty, Ilam University, Ilam, ۶۹۳۱۵-۵۱۶, Iran.
A.A. Pakzad - Water Authority of Ilam Province, Ilam, Iran.

The Kangir dam is under construction on Kangir River in the simply folded Zagros Mountain Ranges in Ilam Province, southwest of Iran. The dam axis is located on karstified Asmari Formation and the dam reservoir is composed of Gachsaran Formation. Developed karst phenomenon like sinkholes are present in the Gachsaran formation. Wide fractures with significant solution are observed in the dam axis during excavations of the dam. A thin alluvial layer covers the reservoir along the Kangir River. There is some springs downstream of the dam axis which drain the Asmari formation. Dye tracing tests in the Asmari formation around the dam reservoir ans also Gachsaran formation showed channelized hydrogeological connections between dam reservoir and the springs. According to presences of karst formations as reservoir and abutments, karst features, thin cover of sediments, geotechnique borehole information and general hydrogeology of the area, this dam most probably will have water leakage both from the axis and reservoir.

Kangir, Dam, water tightness, leakage, karst