Sedimentation of waterways within the proposed 92sq km Project Hayes wind farm site will likely increase due to construction of the development, an Environment Court appeal hearing was told yesterday.
Otago Regional Council water resource scientist Matthew Dale gave evidence about how sedimentation would be affected by Project Hayes, and whether increased sediment could be mitigated.
In response to a question by Judge Jon Jackson, Mr Dale said sedimentation would be increased by earthworks during the project's construction phase.
He said stock grazing on the site caused sedimentation of waterways alone.
But if construction of the wind farm took place while stock continued to graze, there would be a corresponding increase in sediment.
Mr Dale said methods of mitigation proposed for controlling sedimentation on site would be effective.
However, during cross-examination from appellant Ewan Carr, Mr Dale said he would be concerned about increased sedimentation if large rain or snow falls occurred on site and restricted access to certain areas, hampering mitigation or maintenance measures.
Mr Carr believed there was the possibility of "catastrophic" failures in planned mitigation, resulting in sedimentation increases.