Western Catchment forest clearing: PUB to set more measures to blunt impact on wildlife after public feedback

PUB said that acquiring land next to the existing Choa Chu Kang waterworks plant for reconstruction is the least disruptive and most economically feasible. PHOTO: PUB/FACEBOOK

SINGAPORE - Work to fell parts of the Western Catchment forest to expand a water treatment plant is expected to start from 2023, but more measures will be adopted to blunt the impact on wildlife, said national water agency PUB in a recent response to public feedback.

In a statement on its website posted on Nov 10, PUB said it has studied suggestions to explore alternative land parcels for the aged Choa Chu Kang Waterworks – the sole plant supplying treated reservoir water to western Singapore – and noted that relocation would be a major and significantly expensive undertaking.

Of the 121 pieces of feedback gathered from a four-week-long public consultation exercise that ended on Aug 1, the majority called for deforestation to be stopped and biodiversity to be protected, while acknowledging that ensuring Singapore’s water security is important.

The clearance of 3.2ha of vegetation for the expansion near Nanyang Technological University (NTU) will negatively impact flora and fauna in one of Singapore’s largest and most biodiverse forests, an environmental impact assessment (EIA) published in July had concluded.

But relocating the plant would result in disruptions to water supply in areas including Jurong East, Jurong West, Tuas and NTU, said PUB, adding that acquiring land next to the existing plant for reconstruction is the least disruptive and most economically feasible.

The affected plot – equivalent to the size of six football fields – is home to critically endangered Sunda pangolins and straw-headed bulbuls.

The construction works are also expected to affect two freshwater forest streams, which are considered rare habitats.

The endangered Johnson’s freshwater crab – a species found nowhere else in the world – has been recorded in those streams.

Besides reducing the project’s footprint and retaining a 10m-wide vegetated buffer, as recommended in the EIA, PUB said it will adopt some suggestions from the public consultation. These include extending the post-construction monitoring of a nearby freshwater stream where these crabs and other wildlife of conservation importance are found, from three months to 24 months.

Environmental consultant Tony O’Dempsey, who was among naturalists that PUB consulted, said: “Monitoring changes after construction helps to pick up any unanticipated impacts that may occur.

“Detecting the degradation of stream habitat over the initial three months was a bit short because teething problems can take a while to nail down for complex engineering plants like this.”

The construction works are expected to affect two freshwater forest streams, where the endangered Johnson’s freshwater crab has been spotted. PHOTO: KELVIN LIM

PUB has responded to his concern that soil from the site clearance will be washed into the adjacent Sungei Poyan, which runs through the Western Catchment forest, by adding a pond to manage flow into the stream, Mr O’Dempsey added.

PUB will also train workers to manage wildlife encounters, and use some of the salvaged plant species of conservation value and other common native species to reinstate areas along the edges of the proposed development after the project is completed.

Due to the lack of connection between Bukit Timah Nature Reserve and the Western Catchment area, the Western Catchment is a significant source of native flora germplasm – a collection of genes useful for plant breeding, according to the EIA report.

Mr Muhammad Nasry, who leads Singapore Youth Voices for Biodiversity, welcomed habitat enhancement works that will take place post-development, which will give the habitat a chance to recover to some degree.

“A key issue here would be potential human-wildlife conflicts in the adjacent NTU, and we are happy to note that PUB has committed to actively reach out to (NTU environmental group) Earthlink and hall residents in NTU to reduce the likelihood of negative interactions caused by the development process,” said Mr Nasry, who is also part of environmental group LepakInSG. “Our concern about the cumulative impact of the development alongside the Jurong Region Line, which is right next to the study site, still remains.”

While the selected site was the best option to reduce impact, the best possible outcome would have been for none of the areas of high conservation value to be cleared, said Mr Ho Xiang Tian, co-founder of LepakInSG.

He added: “But I also hope the Environmental Management and Monitoring Plan (EMMP) will be implemented properly because sometimes, mitigation measures in the EIA don’t end up in the EMMP and that results in worse outcomes than stated in the EIA.”

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