Groundwater recharge and surface runoff

Assessing the impacts of climate change on the water balance and hydrology is important due to the flow on effects of changes to the water cycle. These flow on effects could include impacts to salinity, erosion, water quality, and aquatic biodiversity. Climate change is projected to impact the hydrological system through changes in groundwater recharge and surface runoff.

Office of Environment and Heritage has used the projections from NARCliM to provide updated information on the projected impacts of climate change on groundwater recharge and surface runoff in the near future (2030) and far future (2070).

Research results

Far future change in annual average change in recharge (left) and runoff (right)


  • Large changes are projected to occur in groundwater recharge and surface runoff by 2070.
  • By 2070 more recharge is likely across most of the state with increased runoff in autumn due to projected increases in autumn rainfall.
  • The alpine areas and southern NSW are expected to experience considerable declines in both recharge and runoff.

What is surface runoff and groundwater recharge?

Surface runoff is the water that flows over a land surface instead of being intercepted by vegetation or soaking into the soil. Factors that influence the relationship between rainfall and runoff include ground slope, soil moisture conditions, soil permeability, vegetation cover, dead litter cover and soil surface properties.

Groundwater recharge is the flow of water into a groundwater system from above. The infiltration of rainfall and downward percolation of water through the soil profile can move below plant roots and eventually reach the water table. Volumes of recharge are influenced by soil properties such as permeability and vegetation properties such as root depth and density.


Download information

Biodiversity Technical Report
Biodiversity Technical Report
Biodiversity Technical Report
Biodiversity Technical Report
Surface Runoff Maps

ASHX - 3.7 mb

Biodiversity Technical Report
Surface Runoff Data

ASHX - 2.8 mb

Biodiversity Technical Report

What is surface runoff and groundwater recharge?

Surface runoff is the water that flows over a land surface instead of being intercepted by vegetation or soaking into the soil. Factors that influence the relationship between rainfall and runoff include ground slope, soil moisture conditions, soil permeability, vegetation cover, dead litter cover and soil surface properties.

Groundwater recharge is the flow of water into a groundwater system from above. The infiltration of rainfall and downward percolation of water through the soil profile can move below plant roots and eventually reach the water table. Volumes of recharge are influenced by soil properties such as permeability and vegetation properties such as root depth and density.