23/09/2025
Hong Kong's Ingenious Solution: Flushing Toilets with Seawater
Hong Kong addresses its persistent water scarcity with an innovative solution: seawater toilet flushing. Implemented gradually since the 1950s, this system currently uses seawater in 80% of toilets, resulting in a remarkable daily savings of 200,000 tons of freshwater—a 20% reduction in overall consumption. This success relies on a separate seawater network, distinct from potable water, though it necessitates specialized, corrosion-resistant materials for pipes and fixtures, increasing maintenance costs. Despite this, long-term cost savings from reduced freshwater treatment and tariffs are significant, fueling plans to expand coverage to 90% of the population. Challenges remain in maintaining the system and extending it to remote areas. However, Hong Kong's seawater toilet system stands as a compelling example of sustainable water management, demonstrating how resource-constrained cities can adapt through innovative engineering and forward-thinking policies. Future plans to integrate wastewater recycling further enhance its sustainability and solidify Hong Kong's commitment to water conservation. The system's success has also inspired similar initiatives in other water-stressed regions globally.
Source:
South China Morning Post:
Seawater flushing to be extended to more Hong Kong toilets next year