The Alice Springs Town Basin Aquifer
Abstract
The township of Alice Springs is situated over a small, Quaternary age alluvial basin known as the Town Basin aquifer. The aquifer, which represents a precious groundwater resource in this arid environment, is recharged during flow events of the Todd River. Within this urban setting, the water and salt balance in any one year is dominated by anthropogenic processes, rather than natural causes. The existing shallow water levels in parts of the aquifer increase the risk of salinisation due to the upward mobilisation of salts in the soil profile. Consequently, there is a need to implement various short- and long-term strategies to manage the resource sustainably and minimise any groundwater quality degradation. It is demonstrated that groundwater levels have, on average, declined by 1 metre since 1992. This is due, in part, to improved management of the aquifer, with the establishment of the Town Basin non-potable irrigation system in 1996, and the associated increased groundwater extraction. A water and salt balance indicates that higher groundwater extractions are warranted in the short-term, both to maximise utilisation of the resource and to control the risk of salinisation. Accordingly, a staged resource development strategy is recommended, with a long-term approach to sustainable groundwater use management.
Authors
Dr Richard Evans, Deborah Green, Nick Fleming
Sinclair Knight Merz Pty Limited
P. Heaton
Power and Water Authority, Northern Territory