The Housing and Development Board (HDB) has engaged an environmental consultancy firm to conduct an Environmental Impact Assessment (EIA) on Bukit Batok Hillside Park in the western region of Singapore.
According to HDB’s website, they “carefully consider the findings from the studies so that (they) can sensitively plan the land use and make adjustments to the Master Plan if needed to mitigate the potential impact, and establish urban design strategies to provide a quality living environment.”
While I commend HDB for initiating the environmental study in their proposal to build more housing units, I have several concerns about the potential impacts of deforestation in Bukit Batok Hillside Park:
- Loss of biodiversity and natural heritage
- Risk of soil erosion and landslides
- Loss of natural cooling effect and increase in urban heat effect
- Loss of cultural and historical heritage
- Loss of connection to Nature and increase in stress and anxiety associated with urban claustrophobia
- Increase in dengue fever cases due to conditions favouring increased reproduction of disease-carrying mosquitoes
During a short hike in and around the forest of Bukit Batok Hillside Park on 5 July 2020, I spotted several animal species, such as oriental whip snake, greater racket-tailed drongo, white-crested laughing thrushes, black-naped orioles, yellow-vented bulbuls, and insect species such as dragonflies and butterflies.
These are merely a fraction of the 81 fauna species recorded in the EIA (and there may be more species that have yet to be discovered during the 9-day wildlife survey). The presence of predators such as snakes suggests a fairly complex food web in this fragile secondary forest ecosystem, which is still recovering from past human disturbance.
Since Tengah forest nearby is currently being cleared to make way for new homes, most of the wildlife there will have nowhere else to escape to, since it is bounded by expressways in the north and west, and by roads along Choa Chu Kang housing estate in the east and along Bukit Batok and Bukit Gombak housing estates in the south.
Some birds may be able to fly across Bukit Batok Road from the disappearing Tengah forest to take refuge in Bukit Batok Hillside Park. However, if the forest in Bukit Batok Hillside Park were to be destroyed too, then there would be a huge loss of the existing biodiversity in this region. This is because Bukit Batok Hillside Park serves as the last remaining node of connectivity between Tengah forest and the forested areas in Bukit Batok town park (Little Guilin), Bukit Batok nature park and Bukit Timah nature reserve.
Although the upcoming Tengah town is designed to have “forest corridors“, they will be closely intersected by roads, pavements and cycling tracks. These do not allow the animal residents to move freely, unlike in a real forest setting such as in Bukit Batok Hillside Park, where they can go about their daily lives – eating, mating, reproducing, sleeping, etc – undisturbed by human presence.
Like Dr Ho Hua Chew, vice-president of Nature Society (Singapore), said, “some species of birds, such as parakeets, eagles and others that can fly longer distances, will be able to use the fragmented patches of forests as stepping stones from the Tengah forest to Bukit Batok Nature Park or the nature reserve and vice versa”. On the other hand, he is also concerned that “wiping out the vegetation (in the Bukit Batok area) further disrupts the route that wildlife can use to move from forest to forest”.
Bukit Batok is blessed with several small forested hills and ridges, which thankfully have helped the town retain its overall green appearance for the most part, compared to most other towns in Singapore. Thanks to their steep slopes, some of these forested hills, such as Bukit Batok neighborhood park along Bukit Batok Street 21 and the hills surrounding Bukit Batok MRT station, have escaped urban development so far.
Hence, I find it inconceivable that Bukit Batok Hillside Park is being considered for housing development, since the steep slopes, especially those adjacent to Bukit Batok West Avenue 2, are prone to soil erosion and landslides if the vegetation cover is removed. The seasonal monsoon rains and late afternoon thunderstorms, which are common in Singapore, add to the risk of natural hazards such as landslides. It is also dangerous and expensive to construct buildings on steep slopes, hence Bukit Batok Hillside Park is not ideal for housing development.
3) Loss of natural cooling effect of forest and increased urban heat effect in the western region of Singapore
According to HDB’s website, “greenery is present in every HDB estate. It helps to reduce temperatures and mitigate heat while improving air quality and biodiversity, besides being pleasing and attractive.”
I agree with that. I would like to add that sizeable forested areas, such as Bukit Batok Hillside Park, help to reduce temperatures in housing estates much more effectively than roadside trees and fragments of ornamental vegetation in town parks in highly built-up areas, such as Toa Payoh.
For example, when I was staying in Toa Payoh in central Singapore, where I grew up in from 1973 to 2014, I could feel the warm humid air on most nights. This is because Toa Payoh is located in a highly built-up environment with fragmented vegetation and lack of a dense forest. After moving to Bukit Batok in the western region of Singapore in 2014, I could feel the difference in temperatures, as the air is cooler on most nights. This is because of the presence of dense forests in and around Bukit Batok.
In fact, the above map shows that on average, the night-time temperature in Bukit Batok is about 1.5 degrees Celsius cooler than that in Toa Payoh. Now that Tengah forest is disappearing and becoming more and more fragmented due to deforestation for housing development, it is likely that the surface temperatures around the neighbourhood of Bukit Batok will rise gradually.
If the forest in Bukit Batok Hillside Park is removed too, then the temperature in the neighbourhood will rise further due to the loss of cooling effect of the dense tree growth. With an increase in urban heat effect, there will likely be an increase in electricity consumption, due to higher usage of air conditioning in homes, especially on warm, stuffy nights. The increased heat will be exacerbated by the ongoing global warming climate, which will inevitably result in more physical discomfort and stress for the residents in the coming years.
In addition, the quality of air is likely to deteriorate if Bukit Batok Hillside Park is sacrificed for housing development, due to increased motor traffic around the vicinity and less natural vegetation to filter air impurities or toxic chemicals and reduce air pollution.
4) Loss of cultural and historical heritage in Bukit Batok
As Singapore becomes more and more modernised, our younger generations face the danger of losing touch with our history, cultures and traditions. According to the EIA report, Bukit Batok Hillside Park comprises a former rubber plantation, with natural freshwater streams, which are rarely seen in Singapore today.
Hence, not only is the forested area worthy to be conserved for natural heritage, it is also worthy to be preserved for having historical and cultural significance. For example, the abandoned well and other relics in Bukit Batok Hillside Park can serve as useful tools for educating the public about Singapore’s history in an authentic setting (like how the abandoned kampong houses in the former Hainan Village are now preserved for public education in Thomson Nature Park).
5) Loss of connection with Nature and increased stress and anxiety associated with urban claustrophobia felt by people
An article by NParks noted that forest therapy helped people to relax, destress and often, enabled them to feel happier and more positive.
“A mental and emotional boost, you may say. And scientific research backs this up.”
– “Urban Forest Therapy in Singapore” by NParks
Moreover, a scientific study “reported that individuals’ positive moods increased significantly inside a forest than outside it or at its periphery, whereas their negative moods increased outside the forest.”
Hence, if the forest in Bukit Batok Hillside Park is destroyed for housing development, it will increase the likelihood of the residents losing connection with Nature, which in turn can be detrimental to their physical, mental and emotional health and well-being in the long run.
6) Deforestation can lead to an increase in dengue fever cases
The above map shows that dengue fever cases are fewer in the western region of Singapore, including Bukit Batok, where there are dense forested areas nearby, such as Bukit Batok Hillside Park, Bukit Batok nature park and Bukit Timah nature reserve, which are relatively undisturbed by humans.
Notably, an academic research paper reported in 2016 that “a growing body of scientific evidence shows that the felling of tropical forests creates optimal conditions for the spread of mosquito-borne scourges, including malaria and dengue.”
Similarly, a Straits Times article reported in 2019 that the ecological history of deforestation in the Philippines – followed by urbanisation, the further degradation of our forests and climate change – continues to explain the tenacity of dengue in the country.
Hence, it is imperative that the authorities take drastic steps to stop or minimise deforestation as much as possible, in order to curb the current dengue outbreak in Singapore, which has become the worst outbreak in recent history.
My Proposed Alternatives
In view of my concerns described above, may I propose the following alternatives?
First, we can consider reinstating Bukit Batok Hillside Park as an enhanced nature park with educational trails and conservation zones.
Second, we can choose to focus on recycling or redeveloping brownfield sites (such as old or disused developed areas) instead of clearing greenfield sites (such as Bukit Batok Hillside Park) for future housing development, as also suggested by HDB CEO Dr Cheong Koon Hean in her IPS-Nathan lecture in 2018.
“Similar to many mature cities, as we become built up over time we will be left with more brownfield rather than greenfield sites. This requires us to shift progressively into an ‘urban redevelopment/regeneration’ mode.
For an island city-state limited by our territorial waters, available land for new development will come mainly from ‘recycling’ existing land and properties.”
– Dr Cheong Koon Hean, HDB CEO (IPS-Nathan lecture, 2018)
Last but not least, we should definitely review our national development master plan, since The Straits Times reported on 3 July 2020 that “recent trends ensure that Singapore’s population will be significantly below 6.9 million in 2030″. Surely we don’t really need to keep destroying our few remaining valuable forests for housing development, given that our population is not expected to increase as quickly as we had once thought?
In summary, by sparing Bukit Batok Hillside Park (and other greenfield sites) from deforestation for housing development and by choosing to develop brownfield sites instead, we can achieve the following benefits:
- Conserve our precious biodiversity and natural heritage
- Prevent soil erosion and landslides
- Retain natural cooling effect, reduce energy consumption and air pollution, and minimise physical discomfort
- Preserve our cultural and historical heritage for posterity
- Retain our connection to Nature and promote health and well-being through forest therapy in close proximity
- Eliminate the root cause of the proliferation of disease-carrying mosquitoes and curb the outbreak of dengue fever.
“We recommend the conservation of these secondary regrowth forest patches as they are, as refuges for nationally threatened native species, which make up about 20% of the species we recorded in each forest patch (namely, Bukit Batok Hillside Park, Bukit Batok Town Park, Bukit Batok Nature Park and Bukit Batok East Forest).”(Source: The Vascular Plant Flora in Bukit Batok, Singapore by National University of Singapore, 2013)