Technical project data HEP Reservoirs net storage capacity (106m3) Net design head (m) DamVolume (103m3) Dam Height (m) Type of dam Messochora (concrete faced dam) 228 200 4000 150 Rockfill with upstream concrete face slab Temenos 6 24.5 90 45 Concrete gravity Metsovitikos 0.25 91.5 200 11 Earthfill Sykia 502 122 12 400 175 Rockfill