How does saltwater intrusion affect the water supply in the South Pacific?

Contamination of Freshwater Sources

1. Thinning of freshwater lenses: Saltwater intrusion reduces the thickness of freshwater lenses that float on top of seawater, diminishing the quality and quantity of available groundwater13.

2. Brackish groundwater: Many South Pacific islands already experience brackish groundwater that is unsafe for drinking1.

3. Aquifer contamination: Saltwater intrusion affects shallow coastal aquifers, which are crucial freshwater sources for many Pacific islands5.

Impacts on Water Infrastructure

1. Damage to water systems: Coastal inundation can cause erosion, saltwater intrusion, and septic overflow, affecting water infrastructure and increasing maintenance costs1.

2. Reduced well functionality: Saltwater intrusion can make subterranean wells unusable or require increased treatment costs2.

Effects on Agriculture and Food Security

1. Decline in crop cultivation: Saltwater intrusion has led to a decline in the cultivation of staple crops like pulaka in Tuvalu1.

2. Soil productivity: Sea level rise and storm surges adversely affect soil productivity in low-lying areas7.

Exacerbating Factors

1. Climate change: Rising sea levels and more frequent droughts increase the likelihood and severity of saltwater intrusion34.

2. Limited freshwater sources: Many atoll nations, such as Kiribati, have extremely limited freshwater sources, making them particularly vulnerable to saltwater intrusion4.

3. Over pumping: Excessive groundwater extraction can accelerate saltwater intrusion, especially during drought periods6.

To address these challenges, Pacific islands are exploring various solutions, including improved water management techniques, the use of infiltration galleries to skim fresh groundwater while minimising saltwater intrusion, and considering alternative water sources such as treated wastewater24.

Conclusion

Saltwater intrusion poses a critical threat to water security in the South Pacific, particularly for atoll islands and low-lying coastal regions. The contamination of freshwater sources, degradation of water infrastructure, and negative impacts on agriculture and food security all contribute to the urgent need for sustainable water management solutions. As climate change accelerates sea level rise and extreme weather events, the vulnerability of these island communities continues to grow.

In response to this crisis, innovative water purification and desalination technologies are becoming essential for ensuring a reliable freshwater supply. LEDI, through its AquaGen desalination systems, provides practical solutions tailored for emergency response, remote communities, and disaster preparedness. By offering robust, portable, and efficient desalination technology, LEDI is helping to mitigate the effects of saltwater intrusion and enhance water resilience for vulnerable island nations.