Saplings of 22 species planted along banks of Punggol Waterway filter bacteria, prevent soil erosion
Shuli Sudderuddin Straits Times 10 Dec 11;
TESTS by Ngee Ann Polytechnic students show that the water quality in the Punggol Waterway is improving after mangrove trees were planted along its banks.
Saplings of 22 species - including endangered ones - were planted in an area spanning 480 sq m in the eastern part of the waterway in June and July.
It is a project by the HDB Building Research Institute (BRI) to further enhance the 4.2km waterway which was opened officially on Oct 23.
The man-made waterway cuts across Punggol town and runs between Sungei Punggol and Sungei Serangoon.
The Housing Board is working with the polytechnic's civil and environmental engineering students to monitor the results of the mangrove initiative.
The students will visit the area twice a month over three years to collect water samples and test their quality.
Mangrove trees are known for phyto- remediation or their ability to take in nutrients like phosphorus and nitrogen from the water and reduce algae growth.
Dr Katayon Saed, a Ngee Ann Polytechnic lecturer who specialises in environmental engineering, said introducing mangrove trees along the waterway helps filter contaminants from the water and prevents soil erosion.
'They definitely improve the area as a recreational facility because the water is cleaner and it is a breeding habitat for lots of life. It's added value for residents,' she said.
Dragonflies, birds, fish, monitor lizards and the occasional freshwater otter have been spotted.
Earlier in the year, the BRI team's challenge was to find out which mangrove trees could grow in freshwater as they normally survive in brackish water.
BRI engineer Seow Wei Kiong said the institute tested 28 species of saplings in its freshwater pond in Woodlands in March. Six species were found to be unsuitable.
In June, saplings of the 22 freshwater- tolerant species - between 0.3m and over 1m tall - were bought. They were planted over two months in 80m-by-3m plots on either side of the waterway.
The saplings are expected to reach maturity in 10 to 15 years' time, and grow to heights of up to 8m.
If this first phase proves successful, a second phase of planting 2km of mangroves, with 1km on either bank, will be implemented after 2013.
Said Mr Mohamad Jauhari Johari, a 19-year-old Ngee Ann Polytechnic student involved in the project: 'We've been testing the water quality twice a month since April and there has been some improvement. And as Singapore is not known for having many mangroves, this has become a really special place.'
