National Centre for Groundwater Management

This document captures our current understanding of groundwater quality, quantity and interaction with rivers. The Namoi catchments are some of the most extensively studied catchments in Australia and the World. But there are still many gaps in our understanding of groundwater which limit our capacity to manage how we allocate between all stakeholders including rural industries, mining, urban users and the environment. To allow for a better informed discussion on groundwater usage improvements are needed in the science underlying catchment management. Estimating catchment scale water fluxes is not an exact science. There are errors in estimating rainfall recharge, river recharge, irrigation returns to the aquifer, inflows through basement rocks, discharge via the rivers, evapotranspiration losses, surface water storage losses, and quantifying flood events. This is why catchment water balances have to be modelled and best estimates given (ideally with confidence intervals). Through improved measurement techniques, higher resolution data and advancement in numerical computer modelling techniques the errors associated with quantifying water fluxes through the catchment can be reduced and water management decisions improved. In some cases the quality of the data can be improved easily