Wilding conifers reduce surface flows and aquifer recharge in water-sensitive catchments.
Less flow means less water for farmers’ irrigation needs, hydroelectric generation, or outdoor recreation use. And less water for those plants and animals that live in and around the river.
Where pasture land becomes covered in wilding conifers, this reduction in annual water yield has been shown to range from 30 to 81 percent (with the upper end of that range recorded in dry South Island sites).
Environment Canterbury (regional council) has identified wilding conifer spread as something that might affect water yields in their region.