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Monitoring of the dam revealed movement, often normal in dams. But the
left side was moving more than the right. This was because the left abutment
was a hillside, more deformable than the right abutment. Also, a support had
been built on the right side of the dam, making that side more stiff (and
less moveable).
In 1977, a crack was noticed just left of the center of the dam about 98.4
ft (30 m) above the foundation on the upstream side of the dam. This is
noted as one of the worst places for cracking to occur in an arch dam. Water
was now leaking out through the crack into drains in the dam at a rate of 53
ft3/min.
In February of 1978, the leak increased to a rate of 318
ft3/min as a result of heavy rain.
The crack grew almost 150 ft both to the left and to the right and could be
seen from one of the dam's inspection galleries.
In 1979, the crack was repaired.
In 1980, maximum storage was reached.
In 1983, it was found that settling had occurred in the foundations and
the movements of the dam caused fracturing in the rock. The permeability of
the foundation had increased significantly.
Treatment of the foundation has decreased the movements and the
foundation.
It is interesting to note that this headline appeared in a Spanish newspaper in
1985. It says that no crack existed in El Atazar Dam. Who would say this, when there
was obviously a crack in the dam? Politicians.
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