Tuamarina River Valley Aquifer
The Tuamarina or Waitohi Valley separates Picton from the Wairau Plain and is drained by the Tuamarina River.
A tributary of the Wairau River, the Tuamarina River flows southwards across a wide floodplain formed of gravels.
A series of aquifers are hosted by these sediments. The main source of water is located within 20 metres of the surface.
Groundwater and surface water interact, with the Tuamarina River gaining channel flow all the way to the Para wetland.
Groundwater is a used for a variety of purposes including stock, domestic, golf course, Picton municipal supply, milking shed washdown and crop irrigation.
At this stage there are no Marlborough District Council groundwater monitoring wells in the area, however, a permanent recorder measures flow in the Tuamarina River at Para Road and Boat Point, which is related to groundwater.
The diagram shows the latest understanding of the aquifer systems beneath the valley floor. Most wells including the Picton municipal well-field tap relatively shallow groundwater, although deeper wells down to 40 metres are known to exist.