In the late 1970s, anyone walking along the banks of the Singapore River would smell it before seeing it. The water was pitch black, filled with sludge, food waste, oil, and sewage from thousands of households that emptied human waste directly into the river using night-soil buckets.
Conditions were just as severe in the Kallang Basin, which receives water from five rivers. The water there contained almost no oxygen, and marine life had virtually disappeared altogether.
What makes these figures striking is not merely the level of pollution, but the scale of the problem. In 1977, there were still 46,187 informal dwellings around the river, most of which relied on night-soil buckets and overhanging latrines that discharged directly into the water.
Within the same catchment area, 610 pig farms and 500 duck farms were operating and disposing of untreated waste, alongside thousands of street vendors and cottage industries. The river was not degraded by a brief period of neglect; it had served as a dumping ground for a city growing around it for more than a century.
One Promise That Triggered a Ten-Year Operation
The idea of cleaning up the river had actually emerged as early as March 1969, when Lee Kuan Yew asked engineers from the Public Works Department and the Public Utilities Board to develop a plan to address water pollution in Singapore.
However, the decisive turning point came on February 27, 1977. While officiating the opening of Upper Peirce Reservoir, Lee gave the Ministry of the Environment what seemed like an impossible target at the time: within ten years, Singaporeans should once again be able to fish in the Singapore River and the Kallang River.
Lee even promised a solid gold medal to every official who succeeded, while warning that he would personally trace the source of failure if the target was not met.
The master plan for the cleanup was drafted after eight months of study and completed in October 1977. The Singapore River and Kallang Basin catchment alone covered roughly one-third of Singapore's total land area, meaning the operation touched nearly every sector of government.
Implementation was led by Lee Ek Tieng, Permanent Secretary of the Ministry of the Environment, and involved more than a dozen government departments, ranging from housing and urban planning to agricultural production.
Removing the Sources of Pollution, Not Just Dredging the Mud
The key to the success of the cleanup operation rested on one simple principle: the water would never become clean as long as the sources of pollution remained. As a result, the authorities did not merely remove sludge from the river; they relocated the activities responsible for contaminating it.
By March 1982, all pig and duck farms within the catchment area had been shut down. Overall, more than 26,000 families living along the river were resettled into public housing developed by the Housing and Development Board, while 4,926 street hawkers were relocated to officially designated hawker centres.
The sanitation system was also completely overhauled. Of the 11,847 night-soil bucket latrines identified, nearly all were eliminated, and Singapore's last night-soil bucket was removed in 1987.
Around 2,800 cottage industries were relocated to newly developed industrial estates equipped with modern sanitation facilities. As for the total cost of the cleanup, academic literature provides two estimates.
A study by Chou, published in Ocean & Coastal Management, estimated the cost at approximately S$200 million, equivalent to US$159.8 million. Meanwhile, Tan, writing in Ambio: A Journal of Environment and Society using more recent data, placed the figure closer to S$300 million (US$239.7 million), excluding resettlement compensation.
The Proof That Swam Back into the River
The cleanup operation was officially declared complete on September 2, 1987, exactly ten years after the target had been set.
During the Clean Rivers Commemoration ceremony, Lee Kuan Yew awarded gold medals to ten individuals in recognition of their contributions. What had sounded like an impossible promise a decade earlier had finally become reality.
The clearest sign that the river had truly come back to life arrived in the form of wildlife returning on its own. Otters, which had been considered locally extinct in Singapore during the 1970s, began reappearing in the late 1990s and are believed to have swum across the Johor Strait from Malaysia.
Their return is significant because otters can only thrive in waterways healthy enough to support large fish populations, making them a living indicator of water quality.
Today, the Singapore River flows into Marina Reservoir, the country's largest freshwater reservoir, which was created after the completion of Marina Barrage in 2008. Its riverbanks have since been transformed into one of Singapore's busiest recreational and tourism districts.
References
- Chou, L. M. (1998). The cleaning of Singapore River and the Kallang Basin: Approaches, methods, investments and benefits. Ocean & Coastal Management, 38(2), 133–145. https://doi.org/10.1016/S0964-5691(97)00069-0
- Joshi, Y. K., Tortajada, C., & Biswas, A. K. (2012). Cleaning of the Singapore River and Kallang Basin in Singapore: Human and environmental dimensions. Ambio, 41(7), 777–781. https://doi.org/10.1007/s13280-012-0279-0
- Kontinentalist. (2019). The otter side of Singapore. https://kontinentalist.com/stories/the-otter-side-of-singapore
- Lee Kuan Yew School of Public Policy. (2012). Clean-up of the Singapore River: Before and after. National University of Singapore. https://lkyspp.nus.edu.sg/gia/article/clean-up-of-the-singapore-river-before-and-after
- National Heritage Board. (2022). The Singapore River. Roots. https://www.roots.gov.sg/stories-landing/stories/The-Singapore-River/story
- National Library Board. (n.d.). Clean-up of Singapore River and Kallang Basin. Singapore Infopedia. https://www.nlb.gov.sg/main/article-detail?cmsuuid=21837345-389f-4856-a82d-a5415c7bb55b
- National Library Board. (n.d.). Otters. Singapore Infopedia. https://www.nlb.gov.sg/main/article-detail?cmsuuid=d1baa5b3-84e6-42b3-83d0-5c16c64faad2
