Punggol Waterway and Reservoir

Punggol Waterway is Singapore's first man-made waterway by HDB. With a length of 4.2km, it meanders through the entire Punggol Eco-Town. Look at the map of the area before the waterway was built in 2010 and that of 2020. Move the slider to the right to see the map in 2010 and move the slider to the left to see the map in 2020.

The design of the waterway and the landscape promenade embraces the area’s rich coastal heritage, providing more opportunities for water-based recreational activities and sports right next to the heartlands. The waterway and the new communal spaces along the promenade provide a vibrant living environment, transforming Punggol into a sustainable waterfront town of the 21st century. 

Source: HBB Punggol 

How will human activities affect the quality of the water in the waterway?

Recreational activities along the waterway often lead to intentional or accidental littering. When plastic waste, food packaging, and other debris enter the water, they do more than just ruin the view; they break down into microplastics and release toxins that threaten aquatic life and degrade overall water chemistry.

When visitors stray from designated footpaths, their footsteps compact the soil, reducing its porosity. This creates a hard, "pavement-like" surface that prevents rainwater from soaking into the ground. Consequently, surface runoff increases, stripping away topsoil and washing silt into the waterway. This process, known as siltation, increases water turbidity (cloudiness), which blocks sunlight from reaching underwater plants.

The expansion of residential flats and commercial malls near the waterway significantly increases the amount of impermeable surfaces (concrete and asphalt). During heavy rain, these surfaces cannot absorb water, leading to a higher volume of runoff that sweeps construction chemicals, dust, and urban litter directly into the drainage system and eventually the waterway.

While feeding aquatic animals may seem harmless, it introduces high levels of organic matter into the ecosystem. Leftover food settles and decomposes, a process that consumes high levels of dissolved oxygen. As oxygen levels plummet, the water becomes "hypoxic," leading to foul odors and potential fish kills, as the animals literally cannot breathe in their own habitat.

PUB personnel conduct regular maintenance cycles. This involves the physical removal of floating debris and the desilting of the waterway. Furthermore, the upkeep of specialized filtration systems is critical; by clearing these filters of trapped sediment and trash, the authorities ensure that the water remains clear and the flow remains unobstructed.

Water boat with conveyor belt to pick up litters from surface of water 

Ways to improve the water quality of the waterway

Floating wetlands  

A platform of three to four modules can support 360kg of plants and 15 wetland species, identified to be the most resilient, were planted onto the floating modules.These are located near the Heartwave Mall and Jewel Bridge along the waterway.  

Improve the water quality of the waterway - the roots from plants on the floating wetlands act as water filters, which can remove excess nutrients in the water and allow more sunlight to stream in to form rich food sources for smaller fishes. Excess nutrients in the water can lead to algal bloom in the water which kills the fish and turn the water greenish in colour. 

Freshwater-tolerant Mangrove trees along the banks

Young saplings of 35 species of mangrove trees — three of which are endangered native species — were then planted along the banks of a 3km stretch that covers 6,000sqm. The stretch lies near a waterfront Build-to-Order housing project called Waterway Woodcress.  

Improve the water quality of the waterway  - the roots from the mangrove trees help naturally stabilise the sloping banks by binding the soil together and reducing the surface run-off of sediments and soil particles into the waterway. This minimises the occurrence of algal bloom. 

Source
Today Online. (2024, May 15). Biodiversity in Punggol boosted through enhanced greenery in the area. Today Online. Retrieved June 26, 2024, from https://www.todayonline.com/singapore/biodiversity-punggol-boosted-through-enhanced-greenery-area 

PUB, Singapore's National Water Agency. (n.d.). Student guide for Sengkang Floating Wetland. Retrieved June 26, 2024, from https://www.pub.gov.sg/-/media/PUB/PDF/Self-guided-ABC-Waters-Learning-Trails/Guide-for-students/Student_Sengkang-Floating-Wetland_Primary.pdf 

Water entering the waterway is cleansed using a variety of natural filters. 

1. Eco-drains along both sides of the waterway act as natural filtration systems to capture and cleanse surface water run-off before discharging into the waterway. 

2. Floating aerators and jet fountains placed at regular interval circulate water and improve oxygen levels, helping to sustain aquatic life. The aerators are turned on by timers or sensors, when the dissolved oxygen level of the water falls below a critical level.

3. The eastern end of the waterway boasts freshwater mangroves, which further enhance water quality through the in-take of nitrates and phosphates, thereby decreasing the growth of algae in the water. 

4. The sloping east and west riverbanks are planted with submersible water plants to help cleanse river water before it enters the waterway.

Source: https://surbanajurong.com/architecture-seeds/the-design-legacy-of-punggol-waterway/

How does PUB manage our reservoir to safeguard our water resource?