The river Tigris flows from Turkey towards Iraq
in its northwestern part dissecting the whole Iraqi territory. During 1981–
1986 a very large earth fill dam was constructed, which is Mosul Dam impounding
the flow of the Tigris River. It is the largest dam in Iraq and one of the
largest in the Middle East. The geological conditions of the dam site and
surroundings, however, are not suitable due to thick exposures of the Fatha
Formation, which consists of marl, clay, limestone and gypsum. The gypsum and
limestone beds are highly karstified causing severe problems to the dam
foundation. Mosul dam suffers from serious problems due to the presence of
karstified rocks; therefore, the Ministry of Irrigation in Baghdad, decided to
construct a protection dam downstream of Mosul Dam; it is called Badush Dam.
The geological conditions at Badush Dam site are the same as those at Mosul Dam
site, which means the foundations of the dam are located on karstified rocks.
Therefore, grouting works were planned and designed and it was partly performed
from the beginning of the construction in 1988. The construction of the dam;
however, stopped in 1991 due to the consequences of the First Gulf War. The
constructed parts of the dam are (30 – 40) %. In this study, we have presented the
main problems, which will cause real danger to Badush Dam, if its construction
is re-started, and we have suggested many requirements to avoid any hazard that
may cause the collapse of Badush Dam.
Keywords: Badush Dam, Mosul Dam, Karstification, Gypsum
rocks, Grouting, Iraq.