What Is a Well?
A well, or bore, is the name given to a hole in the ground to access groundwater and bring it to the surface. The most common type consists of a vertical steel pipe that has an open section at the base opposite the most productive water-bearing layer. Some wells lie flat and are called infiltration galleries.
The open section at the base lets the water in and is called a screen as shown in the adjacent image. Once water is inside the well the pump delivers it to the surface for use. The diagram below is a typical well head with an inspection socket to allow the depth to the water table to be measured, with a bend on top to carry groundwater inside the shed.
Wells can vary in depth from less than 5 metres to 400 metres in depth, but most are 10 to 30 metres deep on the Wairau Plain.
Definition of Well Terms
Allocation and Irrigation
Parts of Marlborough are amongst the driest areas in New Zealand, meaning water is scarce in the drier seasons, even the small quantities needed for drinking purposes.
Map of Wells
There are estimated to have been 5,000 wells drilled in Marlborough over the past century or so since European settlement. Most of these are located on the Wairau Plain.
Once the well is completed the drilling contractor will produce a well log which records the well dimensions, its location, geology and details of the groundwater in the well.
Rules for drilling new wells
If you are looking at drilling a well and taking water from an aquifer, please see the resource consents section for any rules or requirements that may apply to your situation.