Are improvements in irrigation efficiency always a win for water resources?
Our Christchurch based hydrogeologist William Dench and Dr. Leanne Morgan (UC) have investigated the unintended consequences to groundwater following improvements to irrigation efficiency. Their findings have shown that changes in irrigation methods have resulted in reduced recharge to groundwater and reductions in groundwater levels. Groundwater level reductions of up to 17 m have occurred in some areas. Further, the reduction in irrigation recharge has also likely contributed to increased nitrate concentration in groundwater.
In response to the unintended consequences documented in this study, managed aquifer recharge is being implemented as a means of augmenting groundwater levels, quality, and spring-fed waterways. The findings suggest that increased irrigation efficiency may not actually be reducing water use in this region.
You can read their full findings below or by contacting William.