Upper Peirce Reservoir, Singapore
Upper Peirce Reservoir is one of Singapore’s major inland freshwater reservoirs. It lies within the Central Water Catchment area and plays a critical role in the country’s water supply network. The reservoir is enveloped by dense rainforest that forms part of the Central Catchment Nature Reserve, making it both a vital water resource and a sanctuary for biodiversity. Officially opened in 1977 by then Prime Minister Lee Kuan Yew, Upper Peirce Reservoir was created to meet Singapore’s rising demand for potable water and to complement the adjacent Lower Peirce Reservoir.
History of Upper Peirce Reservoir
The idea of expanding Singapore’s reservoir capacity in the central region emerged in the 1960s, as rapid urbanisation increased water consumption. Construction of the Upper Peirce Dam began in the early 1970s across the upper reaches of the Kallang River catchment. The dam impounded the river waters to form a large freshwater body — the Upper Peirce Reservoir — located just upstream from the older Lower Peirce Reservoir, which had been completed in 1912.
The dam was completed in 1974, and the reservoir was officially inaugurated on 27 February 1977. The project was one of several major water infrastructure developments undertaken by the Public Utilities Board (PUB) during Singapore’s post-independence years, aimed at enhancing self-sufficiency in water production. The completion of Upper Peirce Reservoir increased Singapore’s raw water storage capacity by about 60%, marking a significant milestone in the nation’s efforts to reduce reliance on imported water from Malaysia.
Geography and Physical Features
Upper Peirce Reservoir is located in the northern part of the Central Water Catchment, bordered by the Upper Thomson and Mandai areas. The reservoir covers approximately 304 hectares and has a storage capacity of about 27.8 million cubic metres. Its catchment area is largely forested, helping to maintain excellent water quality and providing natural filtration of rainfall before it reaches the reservoir.
The surrounding terrain is undulating, with dense primary and secondary forests that form part of the Central Catchment Nature Reserve. These forests are home to diverse wildlife species including long-tailed macaques, monitor lizards, colugos, and various bird species. The reservoir’s water level fluctuates naturally with rainfall, and access to the water’s edge is restricted to protect the purity of the catchment area.
Hydrology and Catchment System
Upper Peirce Reservoir is part of Singapore’s central reservoir network, which also includes MacRitchie Reservoir, Upper Seletar Reservoir, and Lower Peirce Reservoir. Together, these reservoirs form a hydrologically interconnected system that channels rainwater from the surrounding forest catchments into storage basins for treatment and distribution.
The dam at Upper Peirce Reservoir was engineered with modern design principles to ensure the stability of the embankment and effective control of water discharge. Water from Upper Peirce flows downstream into Lower Peirce Reservoir through a controlled spillway system, maintaining a steady supply of raw water for treatment. PUB closely monitors the reservoir’s inflow, storage levels, and quality to optimise its contribution to Singapore’s overall water management strategy.
Ecological Importance
Because of its location within the Central Catchment Nature Reserve, Upper Peirce Reservoir supports one of the richest ecosystems in Singapore. The surrounding forests act as an essential green lung for the island, moderating temperatures and storing carbon while serving as a refuge for native flora and fauna. The reservoir’s banks are lined with forest species such as dipterocarps, rattans, and gingers, alongside freshwater plants that stabilise soil and reduce erosion.
Wildlife in the area includes native mammals such as the Malayan colugo and plantain squirrel, as well as bird species like the white-bellied sea eagle and oriental pied hornbill. The reservoir’s calm waters are also frequented by herons, kingfishers, and egrets. Due to its ecological sensitivity, recreational activities such as boating and fishing are not permitted at Upper Peirce Reservoir, in contrast to other reservoirs like Bedok Reservoir and Lower Seletar Reservoir, which are open for public recreation.
Public Access and Amenities
Although the reservoir itself is off-limits to the public for water protection reasons, visitors can access the Upper Peirce Reservoir Park, a small yet scenic green space located at the end of Old Upper Thomson Road. The park was opened in 1979 and provides panoramic views of the reservoir and surrounding forest canopy.
Upper Peirce Reservoir Park features picnic shelters, rest areas, and a quiet carpark. The site is particularly popular among nature enthusiasts and photographers seeking to capture the tranquillity of Singapore’s inland rainforest landscape. It also serves as a starting point for birdwatchers and wildlife observers exploring the adjoining forest trails, though these trails are unmarked and require care as they pass through protected areas.
Nearby, the Lower Peirce Reservoir Park offers a longer heritage boardwalk and designated walking trails that showcase the same forest environment. These amenities allow the public to experience Singapore’s natural water catchment areas while promoting awareness of water conservation and environmental protection.
Role in Singapore’s Water Supply System
Upper Peirce Reservoir is a vital component of Singapore’s local water catchment system, one of the Four National Taps that sustain the nation’s water security. The reservoir’s stored rainwater is channelled to nearby waterworks for treatment and distribution across the island. By expanding water storage capacity in the 1970s, Upper Peirce Reservoir significantly enhanced Singapore’s resilience against drought and fluctuating rainfall patterns.
Today, PUB uses real-time monitoring systems to track water levels and quality parameters such as pH, dissolved oxygen, and turbidity. These systems help ensure that Upper Peirce Reservoir continues to deliver clean and safe raw water for treatment. The forested catchment surrounding the reservoir also helps regulate microclimates and rainfall infiltration, reinforcing the natural sustainability of Singapore’s water management model.
Environmental Conservation and Management
Given its ecological sensitivity, the management of Upper Peirce Reservoir is guided by stringent environmental protection standards. PUB works in close collaboration with the National Parks Board (NParks) to conserve the surrounding habitats and maintain water quality. Vegetation clearing and public access are tightly controlled, and non-native species are regularly monitored to prevent ecological imbalance.
The ABC Waters Programme (Active, Beautiful, Clean Waters) further integrates water management with environmental design principles, ensuring that Singapore’s reservoirs and waterways function as both ecological and aesthetic assets. Although Upper Peirce Reservoir remains largely untouched by recreational development, it contributes significantly to Singapore’s image as a City in Nature — balancing human needs with environmental stewardship.
Interesting Facts about Upper Peirce Reservoir
- The reservoir was named after Robert Peirce, Singapore’s Municipal Engineer from 1901 to 1916, who also oversaw the design of the earlier Lower Peirce Reservoir.
- It has one of the highest water storage capacities among Singapore’s inland reservoirs, surpassed only by Upper Seletar Reservoir and Marina Reservoir.
- The dam site is not accessible to the public, but the nearby park offers one of the most serene viewpoints of Singapore’s forest landscape.
- Because of its protected status, the water quality at Upper Peirce Reservoir is among the best in Singapore’s freshwater catchments.
Conclusion
Upper Peirce Reservoir stands as a symbol of Singapore’s foresight in managing its water resources sustainably. From its origins as a strategic expansion of the early Peirce system to its present-day role in national water security, it exemplifies how careful planning, engineering, and environmental protection can coexist. Surrounded by lush forests and alive with biodiversity, Upper Peirce Reservoir is both a cornerstone of Singapore’s water infrastructure and a quiet haven of natural beauty at the heart of the island.
Upper Peirce Reservoir is 
on the Map of Reservoirs in Singapore
References
- Public Utilities Board (PUB) – Singapore’s National Water Agency
- Wikipedia: Upper Peirce Reservoir
- National Parks Board (NParks)
- Singapore Infopedia – Upper Peirce Reservoir
Page Details
This page was created on 5 October 2025. Hi, my name is Timothy and created it from my research, for my own entertainment, knowledge and to satisfy my curiosity. I am providing the information to you in good faith and hope it is useful. I try to get the details as accurate as possible. I also try to update the page whenever I stumble on new details. So this and all my other pages are perpetual work in progress. If you discover any error, please politely inform me, pointing out where the error lies, and I will correct it as soon as possible. Your helpfulness will keep this page accurate, relevant and helpful to those who need the information.List of Reservoirs in Singapore
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