Sub-standard construction techniques and inadequate drainage on the site of the €60 million wind farm at Derrybrien in Co Galway led to the major landslide there just over a year ago, a court heard yesterday.
Director of services for roads and transport with Galway County Council, Mr John Morgan, said construction techniques on the site were "fraught with danger and should never have been allowed".
A joint prosecution has been taken by the council and Shannon Regional Fisheries Board against Gort Wind Farms Ltd of Tralee, ESBI Engineering Services Ltd and Ascon Ltd of Kill, Co Kildare, arising out of the landslide which occurred at Derrybrien on October 16th, 2003.
The three parties are accused of allowing polluting material including soil and peat to enter the water.
Mr Morgan told Gort District Court yesterday that the developers and contractors on the site had been reluctant to accept any responsibility for the landslide and did not really co-operate with the council at the time.
He said it was likely that the slide had been caused by the piling of hundreds of tons of excavated material from the turbine site on the weak peat soil adjacent to the site.
He said any material excavated from the turbine sites should have been removed immediately and significant site investigations should have been carried out before any work began.
Miss Nuala Butler SC, for the council, told the court that in the wake of the landslide various engineers from the council, as well as external experts, visited the site to assess the extent of the risk of pollution to the river and to see what steps could be put in place to limit this risk.
She said the prosecution would show evidence that the excavation works for the turbines were being carried out in a manner which posed a risk of this type of landslide occurring.
Miss Butler pointed out that there was evidence that similar types of land movement had occurred adjacent to two of the turbine sites prior to the major landslide which should have indicated to the developers that the instability of the land needed to be addressed before the works continued.
Senior engineer in charge of national roads design with Galway County Council, Mr Jack Eising, and senior lecturer in Civil Engineering at NUI Galway, Dr Michael Rogers, both expressed their opinion to the court that the landslides had been caused by the construction activities on the site.
They said it was caused in particular by the piling of the excavated material on weak soil and the lack of adequate drainage.
