EGU24-13495, updated on 09 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Event-based groundwater recharge: drip observations reach new depths in mine tunnels

Wendy Timms1, Andy Baker2, Margaret Shanafield3, Martin Andersen2, Stacey Priestley4, and Marilu Melo Zurita2
Wendy Timms et al.
  • 1School of Engineering, Deakin University, Waurn Ponds, Australia (
  • 2UNSW Sydney, Australia
  • 3Flinders University, Adelaide, Australia
  • 4CSIRO, Adelaide, Australia

Drip sensors in underground spaces such as mine tunnels can quantify vertical water flux through the vadose zone during rainfall events. Australia’s National Groundwater Recharge Observing System (NGROS), established in 2022, provides the first dedicated sensor network for observing the recharge of groundwater at an event-scale across a wide range of geologies, environments, and climate types. As part of this program, differences in recharge fluxes and patterns through fractured metamorphic rock were analysed for hourly data in a shallow mine tunnel (14 sensors at ~30-50 m below ground) and a deep mine tunnel (12 sensors at ~115 m below ground). Average annual rainfall varied from <500 to >1200 mm per annum at the deep and shallow tunnel sites respectively. Recharge was evident despite a thick (>100 m) unsaturated zone above the tunnel. In the shallow mine tunnel, distinct recharge pathways including fracture zones around quartzite intrusions were evident, and time-lags were relatively short. Data analysis will include patterns of rainfall thresholds at which vertical fluxes occur, and spatial patterns within tunnels and between different sites in the NGROS network. The drip data can be useful for managing mine water related risks, and to complement recharge estimates from other methods for sustainable groundwater management. 

How to cite: Timms, W., Baker, A., Shanafield, M., Andersen, M., Priestley, S., and Melo Zurita, M.: Event-based groundwater recharge: drip observations reach new depths in mine tunnels, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13495,, 2024.

Supplementary materials

Supplementary material file

Comments on the supplementary material

AC: Author Comment | CC: Community Comment | Report abuse

supplementary materials version 1 – uploaded on 14 Apr 2024, no comments