Groundwater and Sea-Level Rise: Impacts and Considerations

A new study, "Empirical models of shallow groundwater and multi-hazard flood forecasts as sea-levels rise", by Cox et al. (2025), published in Earth's Future, examines the impact of rising groundwater levels due to sea-level rise (SLR) on coastal cities, with Dunedin, New Zealand, as a case study.

Measurements & Modeling
The study integrates data from monitoring stations and geospatial models to analyze groundwater levels and their responses to tides and rainfall. The models project how these levels will change under different SLR scenarios, predicting areas at risk of flooding from groundwater and coastal inundation.

Challenges
Assessing the risks is difficult because the effects occur gradually, and the thresholds for damage vary. Furthermore, uncertainties arise from assumptions about soil structure and water flow.

Conclusion
The study shows that rising groundwater is an often underestimated threat that will intensify with sea-level rise. Particularly problematic is that groundwater flooding cannot be stopped by topographic barriers and can affect areas far inland.

A key takeaway is that coastal regions must be prepared not only for direct sea flooding but also for "flooding from below." Long-term monitoring programs and adaptive urban planning are crucial to detect damage early and develop countermeasures.

Read full study

Devices for waterlevel & groundwater monitoring: DL-MBX, DL-PR26, DL-PR36, DL-PR36CTD, DL-CTD10B