The Lower Waihopai Aquifer is the name given to all groundwater resources underlying the broad floodplain of the Waihopai River north of Craiglochart bridge.
The photo shows Gibsons Creek at State Highway 63, which is likely to be the source of recharge for groundwater on the upper terraces close to Delta Hill.
Most wells are less than 20 metres in depth, reflecting their dependence on nearby rivers or streams for recharge. There are also many infiltration galleries.
No high-yielding aquifers are known to exist away from the Waihopai River or Gibsons Creek, or at depth.
In part this reflects the clay-bound nature of local gravels.
The groundwater resources of the area are not fully understood and no permanent recorder sites exist. Our conceptual understanding of the aquifers is illustrated in the drawing.
Aquifers are hosted by thin gravels forming veneers on the higher terraces, or forming part of the Waihopai River floodway.