We have been monitoring groundwater table levels within the Mount Maunganui/Pāpāmoa area for over 15 years.
In the past five years we have expanded that monitoring programme to include more areas in Tauranga, and installed continuous monitoring so we can track how the groundwater table responds to sea levels. We now have 93 established sites where we record groundwater levels every 15 minutes.
Monitoring locations (4.3mb pdf)
This monitoring enables council and developers to calculate the current groundwater table levels for use in subdivision and development processes – helping to determine the appropriate ground levels and foundation levels for houses and infrastructure.
Infographic: groundwater level monitoring in near-coast areas (1.5mb pdf)
The effects as we know them of a rising groundwater table include potential leakage into the wastewater system, impacts on buried services like water pipelines, and rising damp in buildings.
Infographic: impacts of shallow groundwater (698kb pdf)
We also use the data in other natural hazards assessments such as our current work to map liquefaction-prone areas.
Tauranga Groundwater Monitoring June 2019 Results
TCC commissioned Tonkin & Taylor to determine typical groundwater levels, spring to autumn seasonal fluctuations, tidal influence and response to rainfall events. The outcomes of the assessment provide estimates of the 95th and 50th percentile groundwater levels have been made.
Tonkin and Taylor's Tauranga Groundwater Monitoring – June 2019 Results (2.6mb pdf)
Groundwater mapping viewer
You can see and explore the maps produced. This viewer allows you to select a specific property and find the current inundation area as well as see what the potential inundation hazard could look like over time, for a range of sea level rise scenarios and storm event likelihoods.
To use the inundation map viewer:
- Open the viewer using the link below
- Enter the address for the property you would like to see details for at the top left
- Layers in the viewer are available in the top right
Groundwater mapping viewer
Current data
Data from the monitoring programme can be obtained by contacting our infrastructure planning team on 07 577 7000 or info@tauranga.govt.nz
We are working to provide this data on our website as a map layer, and expect to be able to release this around mid-2019.
Next steps
Monitoring to date has shown that the groundwater table in areas affected by coastal tides has risen over time, like sea levels have. It is likely that the groundwater table will continue to rise at the same rate as sea levels.