Oral Presentation NCGRT/IAH Australasian Groundwater Conference 2019

Use of multiple methods for studying recharge/discharge processes in regulated and unregulated reaches of the Dumaresq River (355)

Dawit Berhane 1 , A. McKay 2 , T. Mullins 2 , S. Wells 2 , N. Corbett 1
  1. Department of Environment and Science, Brisbane, QLD, Australia
  2. Department of Natural Resources, Mines and Energy, Brisbane, QLD, Australia

Rivers of arid and semi-arid regions of Australia are among the most variable in terms of discharge of any rivers worldwide and are characterised by extended periods of no flow regimes. During extended dry spells, aquatic habitat are able to survive in billabongs.   

Since the onset of the current drought, there has been several environmental flow releases from the Glenlyon Dam, located on Pikes Creek, a tributary of the Dumaresq River. The environmental flows mitigated dry conditions to maintain aquatic ecosystem health and services, by filling and connecting waterholes.

In this paper, hydrogeological processes (recharge/discharge) of the Dumaresq River are studied, at different spatial and time scales, using multiple methods. The study area extends from Glenlyon Dam to Keetah Bridge, representing unregulated and regulated reaches. The methods used are:

  • Conjunctive analysis of surface water gauging stations and groundwater monitoring networks in QLD and NSW
  • Heat as a groundwater tracer
  • EC routing, and
  • Normalised Difference Water Index (NDWI).

Understanding of hydro(geo)logical processes at a reach scale will lead to better informed surface and groundwater management in the upper parts of the Border Rivers basin.