ABSTRACT
The paper presents and discusses incidents and failures that have occurred in Greek Dams. The incidents and failures are grouped according to the mechanism that caused the incident. The first and most common mechanism involves internal erosion, mostly in homogeneous embankment dams. There are nine cases reported. In some, the deficiency was treated, and the dams are properly operating. In others, the reservoir is lowered waiting for remedial measures. In a few cases, erosion was not controlled and led to dam breach. The second mechanism involves overtopping of dams. There are seven reported cases. In many cases, the dam was badly damaged and had to be repaired. In some cases, very little or no damage occurred, mainly due to the rockfill of the downstream shoulder. A review of design floods and probable works to enhance spillway capacities are needed. The last group concerns excessive leakage. Four cases are reported, one concerning extreme leakage in the reservoir. The other cases involve excessive leakage through the foundation/abutments which are difficult to treat successfully. Investigations are ongoing to find a solution in each case. Most of the incidents would have been avoided if well-established principles, such as presented by ICOLD Bulletins, had been followed. The need for dam design and construction made by specialists and not by inexperienced personnel is apparent.
