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Groundwater availability

Why we monitor groundwater availability

Waikato Regional Council monitors groundwater availability to protect our region’s groundwater resources. When too much groundwater is taken from aquifers1:

  • Groundwater levels decline.
  • There may not be enough water for everyone to use, resulting in competition for water.
  • Less groundwater flows into streams. Low stream levels can affect stream-life such as fish and invertebrates.
  • Land may subside.
  • In coastal areas salt water may flow into coastal aquifers and contaminate groundwater as the water table drops.

Photograph of a person filling a glass from a tapGroundwater makes up about 90 percent of our region’s freshwater resource, and is used for drinking, industry, agriculture and horticulture. Waikato Regional Council monitors groundwater availability to help protect our region’s groundwater supplies and ensure we use them sustainably.

What's happening?

Waikato Regional Council monitors ‘available’ levels of groundwater to ensure groundwater resources are used sustainably.

‘Available’ groundwater is the total volume of groundwater that can be taken from an aquifer without affecting the aquifer. This simple assessment of available groundwater treats the aquifer in isolation to any connected streams and rivers.  Areas listed as having low or medium stress may be having a significant impact on nearby streams and rivers.  This impact on streams and rivers is managed separately through the resource consent process, when people request to take groundwater, and may restrict the ability to take groundwater.   As more water is taken from an aquifer, the volume of ‘available’ groundwater for future use drops. We estimate the level of stress on groundwater resources by comparing the volume of ‘available’ groundwater to the volume that’s already been allocated for use.

Waikato Regional Council divides the groundwater resources we monitor in our region into three categories: low, medium and high stress.

  • Low stress areas have less than 10 percent of available groundwater allocated for use.
  • Medium stress areas have between 10 and 30 percent of available groundwater allocated for use.
  • High stress areas have more than 30 percent of available groundwater allocated for use.

>>Find out more about these data and trends

More information

More detail on this indicator, including how and where  Waikato  Regional Council collects this information, is available in the Technical Information page.

Useful links

When this indicator is updated

This indicator is updated every three years. 

Contact at Waikato Regional Council

Hydrogeologist - Science and Strategy Directorate


  1. Aquifers provide natural water storage underground, holding ‘usable’ volumes of water within rock cracks or porous sediments (such as sand and gravel).

Updated July 2017