What is groundwater?

We are the state agency responsible for managing and allocating NSW groundwater resources. This is achieved through the development and implementation of policies  and water sharing plans. We also report on the condition of the state’s groundwater resources based on the analysis of groundwater monitoring data. Our groundwater modelling team is responsible for the development and maintenance of groundwater flow models to guide long term decisions on groundwater management. Information on individual bores can be accessed from Allwaterdata

What is groundwater?

Groundwater is the water contained within rocks and sediments below the ground's surface in the saturated zone.

Groundwater occurs everywhere below the ground but the ability to get the water out of the ground (called 'yield') and the salinity of the water can vary widely depending on the geology and the amount of recharge a groundwater system receives. Recharge is the movement of water into a groundwater system such as from rainfall, flooding, rivers and streams.

What is a groundwater system?

A groundwater system is any type of saturated sequence of rocks or sediments that has similar hydrogeological characteristics and is in hydraulic connection. The characteristics can range from low yielding and high salinity water to high yielding and low salinity water.

What is an aquifer?

The term 'aquifer' is commonly understood to mean a groundwater system that can yield useful volumes of groundwater. This also implies that the water is of good enough quality to be used for purposes such as irrigating crops or for town or stock drinking water. Aquifers are not underground rivers or streams.

Why manage groundwater?

Groundwater is an important resource for many towns, industries and irrigators who rely on groundwater extraction to support their activities. Also, many landholders rely on groundwater for domestic and stock use. Groundwater is also important for the environment, as it supports some ecosystems and provides baseflow to rivers.

Over-extraction or contamination of groundwater can have serious, long-term and sometimes permanent impacts on the groundwater system. This may ultimately reduce the volume and quality of water available for the users and ecosystems that depend on this groundwater.

How is groundwater managed in NSW?

In New South Wales groundwater is managed at the 'water source' scale under the rules of a water sharing plan. Water sharing plans  apply to all of the water extracted in the State. These plans manage both surface water and groundwater that is used by irrigators, the environment, industry, towns and communities. Groundwater is managed in 240 water sources across 50 water sharing plans in NSW.

Water sharing plans aim to:

  • clarify the rights of the environment, basic landholder rights users, town water suppliers and other licensed users
  • define the long-term average annual extraction limit (LTAAEL) for water sources
  • set rules to manage impacts of extraction
  • facilitate the trading of water between users.

Groundwater sources are divided into four broad hydrogeological types:

  • alluvial (unconsolidated sediments)
  • coastal sand (unconsolidated sediments)
  • porous rock (consolidated sedimentary rocks)
  • fractured rock (igneous and metamorphic rocks).

A groundwater source can include a number of aquifers and groundwater systems and are based on geological formation types. Groundwater sources can overlie one another causing part or all of another groundwater source to be buried.

The NSW government is developing water resource plans  as part of implementing the Murray-Darling Basin Plan. These water resource plans will build on existing water planning and management that have already been established in NSW. There will be 13 groundwater water resource plans in NSW under the Basin Plan.