29 March 2016
Sparmos Dam – a significant dam failure in Greece on Sunday 27th March
Posted by Dave Petley
Sparmos Dam – a significant dam failure in Greece on Sunday 27th March
In Elassona, Greece the Sparmos Dam overtopped and breached in the afternoon of Sunday 27th March. Geotechpedia has a short article with some images. There is a better set of images on the Michanikos.gr website. An edited Google translation of the description is as follows:
Thousands cubic meters of water poured onto the plain of Elassona, destroying roads and fields with crops when the Sparmos dam broke on Sunday. The surge of water, indeed, was such that it even dismantled the pavement.
The breach in the dam itself is quite dramatic:
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Fortunately downstream damage appears to be light. Note the shallow landslide on the inner face of the dam wall, on the right side of the embankment. I suspect that this is a drawdown landslide, triggered by imbalanced high pore water pressures in the embankment when the water level rapidly dropped. Michanikos.gr also has a close up of the breach itself:
It seems fortunate that the damage was not more serious. EPT reports (in Greek) that there are plans to rebuild the damaged portion of the dam to restore its capability to store water. It seems important to understand first how the overtopping event occurred.
I note in the last photo on the Michaikos.gr web article that there is vegetation growing on the flat well below the level of the dam crest, suggesting (to me) that the dam had been partially full for a season. Unless this was a storm-created sudden filling and overtopping episode, maybe there was a piping issue in the dam itself. Looks to be a basic earth fill dam. Maybe there was an outflow structure where the breach is and the seal around it failed?
It seems fortunate that the damage was not more serious. There are plans to rebuild the damaged portion of the dam to restore its capability to store water. It seems important to understand first how the overtopping event occurred [non-relevant link removed D]