Groundwater well construction

Why we monitor groundwater well construction

This indicator monitors the number of resource consents issued to drill and construct wells below the groundwater table, and the location of those wells. This helps us understand the pressures from development on lcoal and regional groundwater resources.

The region’s groundwater wells supply drinking water for people and animals, irrigation water for agriculture and horticulture activities and water for industrial use. Groundwater wells and piezometers (narrow wells) are also constructed for monitoring and investigating purposes.

Resource consents (permits) are required from Waikato Regional Council for drilling and constructing wells. The consents have conditions attached to them, to help avoid or lessen impacts of the drilling and construction on the water.

Managing groundwater well construction is important as poorly constructed wells can result in badly affect water supplies. Poor well construction can result in uncontrolled groundwater leakage. Inadequate sealing at the well-head can lead to direct contamination of the groundwater, and mixing of isolated aquifers due to the well construction can also affect water quality.

Contractors are required to keep drill-logs as part of their resource consent. These logs provide an important source of information on groundwater resource investigation and management. Waikato Regional Council also checks consented wells to ensure that they are properly constructed, completed and compliant.

Drilling activities above the water table, and temporary drilling (for example, site investigation), are excluded from this indicator as no resource consent is required.

What's happening?

The Waikato region’s groundwater makes up about 90 per cent of our fresh water resource. On average, 345 applications for well construction per year have been issued between 1990 and 2020. A total of 355 applications were received in 2018, slightly above from the previous year. Most well sites are in the Hamilton Basin, southern Hauraki Plains and Pukekohe areas.

Methods - How we monitor

Monitoring sites
Waikato Regional Council collects information about groundwater wells through the processing and compliance monitoring of resource consents for well construction.
Monitoring frequency
Waikato Regional Council collects information for every consented site at the time of application. We monitor about 20 per cent of the wells for which we have issued drilling permits to ensure appropriate construction and compliance with the resource consent conditions. This happens within a year after construction. Some wells may need further monitoring if we identify problems.
Monitoring history
Resource consents were required to drill and construct wells in the former Waikato Valley Authority area from 1988 to 1990.Waikato Regional Council has issued resource consents since 1990 for the Waikato region.
Measurement technique
Data is provided to Waikato Regional Council as part of consent application for well construction. Compliance data is collected for about 20 per cent of well sites checked by Waikato Regional Council compliance staff. Well logs are received as a requirement for all consents.
This indicator presents the number and distribution of consents issued for groundwater well construction in the region for the years 1990–2015. The distribution of wells consented is mapped using geographic information systems (GIS).
This indicator relates to the number of consent applications for wells or drilling activities. Therefore, it is not an indicator of the:
- total number of wells
- number of abandoned wells
- allocation of groundwater.