Singapore’s Four Taps strategy is at the heart of its resilience to drought as is evident by the city-state’s management of a 2-month dry spell (meteorological drought) at the beginning of 2014. The Four Taps are (1) local catchment runoff water stored in 17 reservoirs; (2) water imported from the Malaysian State of Johor; (3) desalinization of ocean water; and (4) recycled grey water, called NEWater.
During the drought, small streams in both forested and urban catchments ran dry. Open water bodies including ponds and reservoirs shrank substantially in size.
Despite being a rare meteorological event for Singapore, little action was taken to preserve water during the dry spell, compared with neighbouring Malaysia and Thailand where extended dry spells and droughts are relatively common. Thus, Singapore’s ability to maintain business-as-usual water consumption was a testimony to the efficacy of the Four Taps strategy and the resultant resilience to meteorological drought.
Are Singapore’s efforts enough if impacted by drought as climate changes?
Singapore is listed by the World Resources Institute as one of 36 countries in the world with high water stress largely because of its dense population and the paucity of freshwater lakes and aquifers to extract fresh water.
Despite recognition of high water stress, Singapore still uses more water per capita than many other countries (per capita domestic water consumption = 151 l/day). The target is to lower Singapore’s daily per capita domestic water consumption from 151 to 140 l by 2030.
Reducing demand has proven much harder than expanding supply in a country that has sufficient financial resources and has invested heavily in water resources management and technology.
Currently, the projected impacts of climate change for Singapore are uncertain, owing to the island’s small size relative to the large regional domain of its governing climate. Yet these Four Taps will have to work harder in a changing climate, coupled with a projected increase in water consumption and planned reduction of reliance on imported transnational water.
This summary is based on the paper Increasing Singapore’s resilience to drought.