Qaraoun Dam is the largest dam in Lebanon, both in terms of reservoir capacity (220 Mm3) and size (60 m high). It is also a key asset of the Litani River Authority (LRA). The dam provides income through the production of electricity (a total of 190 MW in three hydroelectric power plants) and supplies irrigation water to agricultural lands. Built in 1960, the dam is aging well but requires close monitoring to keep providing benefits to the country for years to come and remain safe for downstream populations and properties. Qaraoun Dam is also located close to the Yammouneh fault, one of three major fault lines in Lebanon which has suffered from several large earthquakes in the past.

Since the completion of construction of Qaraoun Dam in the early 1960s, monitoring of the performance of the dam’s has included the basic elements of a sound program for this type of dam:

- Surveysofdamdeformation;
- Measurements of seepage or leakage flows (through damand foundation);and
-Piezometric measurements downstream of the dam.

Due to uncertain times in Lebanon (Civil War 1975-1990, conflicts with neighboring countries), such measurements and their reporting have been sporadic. The monitoring has however been thorough enough to detect potential issues such as leaks through the upstream facing of the dam. These leaks were accurately located through diver inspections in the past, and recently through the use of an underwater remotely operated vehicle. A major maintenance activity has then been the repair of the rubber water stops of the dam concrete facing to limit leakage. Rehabilitation of the water stops was accomplished in 1979 and again in 1989 and 2010.

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