Oral Presentation AFSS/NZFSS Joint Conference 2019

Tips and tricks for understanding shallow groundwater-surface water interactions (#100a)

Wendy Timms 1 , Bill Howcroft 1 , Devmi Kurukulasuriya 1
  1. Deakin University, Waurn Ponds, VICTORIA, Australia

Base flows or return flow from shallow groundwater surface waters can be important for ecosystems in many areas. This talk will share tips and tricks of how groundwater data can contribute to studies of creeks and wetlands. Field examples will be included of groundwater interactions with surface waters near urban developments and engineering projects. Monitoring piezometers and wells and water level data collection can be designed to answer specific information gaps about the connections between surface and groundwater, and the potential direction of flow (eg. upwards connected, downwards connected or disconnected). Environmental water tracers can be combined with physical groundwater data to provide more confidence on estimated rates of groundwater discharge, or contaminant loads from shallow groundwater that is connected with surface waters. For example, our research combines readily monitored physical parameters such as water temperature, with more advanced water tracers such as radon, isotopes and other unique water fingerprinting techniques. However, environmental water tracers and physical groundwater data could also show that surface waters are variably disconnected from groundwater, with implications for stygofauna  and other groundwater dependent ecosystems (GDEs). In summary, it will be argued that groundwater data can provide important insights into the functioning of surface water ecosystems, and can trigger adaptive management actions to mitigate the impacts of human activities.