THE DEATH OF SHA KOK MEI STREAMS
Contributed by Charles Frew, Sai Kung Association
Cascading down from the Ma On Shan catchment, a number of pristine streams flow down the steep sided slopes and meander across the wetlands beneath Nam Shan and Sha Kok Mei before entering the sea next to the main pier in Sai Kung.
Sha Kok Mei is surrounded by two of these streams, called south and north. These streams link up and have been cause for village unrest and public works in the last couple of years.
The current natural state of the streams, less than 100 metres upstream of the construction works, is far different from what is going on downstream.
| Sha Kok Mei's south (right) and north (left) streams 100 metres upstream of construction works |
Natural stream and flood control habitat is fast disappearing and at considerable expense, with no real justification. Journey from Sai Kung to Sha Kok Mei and you'll see that approximately 1,000 metres of this stream has already been channelised. The ghastly impact is none clearer than the nullah running past the police station, under the stadium car park and bus terminal and out to sea.
The wildlife that also once inhabited or has now been pushed out from this area include a rich diversity of avifauna, snakes, bats, dragonflies, butterflies and a roaming herd of wild cows.
The latest government project in Sha Kok Mei is under the Highways Department (HD), which has spent millions of dollars on its road improvement scheme, and ironically included channelisation (the art of confining the stream to a concrete box or nullah) of the south stream.
Pay a visit to Sha Kok Mei and witness the unbelievable mess this department has single-handedly carried out.
What this means is that any ecological niche that the stream once had as it flowed through Sha Kok Mei has now irreversibly vanished and been buried under concrete or box culverts under the pretence of flood control and drainage.
| The south stream mess |
HD's definition of ‘streamification’ has now straightened the stream (thereby increasing the speed of the stream flow), uniformly lined the streambed with gabions of rock, with no vegetation or pools and transformed the banks into vertical concrete nullahs.
No effort at all has been made to try and recreate the habitat or make it wildlife friendly. The design of the improvement helps Drainage Services to quickly clean and unblock rubbish that has been thrown into the concourse, from plastic bags to shopping trolleys to vegetation.
More recently, the Sai Kung Association learnt that improvement works were also happening to the north stream, and immediate objections were placed with the Sai Kung District Office (SKDO), thus delaying the start and design of the project.
An illegal road has been in place for many years, with individual plot developers entirely at fault for its existence. Since there is no access to the north village, the dumped construction waste was piled along the stream with no support and a concrete bridge with no through flow was erected across the stream.
| Wrecking of the north stream |
Subsequently during the heavy summer rains the bridge becomes blocked and the road submerged underwater by more than one metre. Sadly, a woman died crossing this bridge in her car and now the SKDO has decided to lay a standard dual road with all the trimmings.
However, during the design stage they took a chapter out of the engineering guidebook and have insisted that the road be built on top of the existing illegal road, yet wider and straighter and with box culverts! The reason, we were told, is that ‘riverine systems’ are basically free land to develop and build on. To put a new bridge and resume adjacent private land is too expensive, but can be used for temporary access. Yet to fill in a stream is cheap and has fewer objections from surrounding landowners.
The objections raised with the SKDO were and still are:
• Why insist on building access roads on flood plains?
• What value are the streams to the biodiversity of Hong Kong and more importantly to Sai Kung as a whole?
• Can the road size be reduced and include pedestrian/cycle tracks?
For all these projects (and many more to come) at the onset the concern should be habitat conservation, rather than habitat destruction. The need for government departments to be aware that more transparency is needed in the planning process of developments through public consultation is paramount, especially when it comes to degrading valuable habitat. For the more concrete that is laid down, the less rainwater is soaked up and stored in wetlands, and therefore the greater surface run off causing flooding.
As for Sai Kung, can we seek consensus and ask the SKDO to revitalize the estuary/stream that flows out into the typhoon shelter? I for one would like to open up that stretch and recreate an estuarine environment and a natural streambed rather than a concrete nullah, which by all accounts is set to extend and creep up past Sha Kok Mei (with proposed new land developments) and on up towards Nam Shan and Ma On Shan.
Photo Credit: Charles Frew, http://www.asiaticmarine.com