THIS story is about long lost “self-purifying” ability of rivers in Sabah. But all of a sudden, Daily Express roving reporter found one.
A crystal clear Saliu river knocked out by a massive deluge one night and regained complete purity the next.
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It’s no big name and might like its dominant peers - Kinabatangan, Padas, Segama when turbidity overwhelmed clarity 40 or more years ago and never recovered since.
The gladdening exception is the Saliu river in Murut heartland Pensiangan – a lowly name probably 100pc of Sabahans have never heard of.
But it’s time to exalt the lowly, the unsung, the overlooked, to discover its deep internal workings have been long lost from its famous peers.
Padas river – once tea red now mud flow
The Padas river for example is my sorrow, my lament.
1986, I took my first train trip to Tenom as a pioneering roving reporter.
Then, I saw pure red tea colour waters roaring down multiple rapids through Padas Gorge.
What a scintillating sight of purity that elevated my opinion of Sabah sky high.
But come 1990, another train trip.
My goodness, the powerful mix of awe, magical, breath taking mystery of seeing reddish brown tannin-rich river roaring down the Gorge evaporated, gone, leaving a river like plain mud flows.
Padas had never returned to its tannin-rich self.
The loss seems permanent. Is this called forever Sabah” But as a roving reporter, I knew what happened.
In both previous and subsequent forays into Long Pasia – the highland headwaters of the Padas, I saw its once rich dense Agathis forests hacked asunder from 1990, leaving a forlorn scene of destruction, while massive logs weighted down fleets of logging trucks which sank deep grooved indentations into heavily eroded roads from which mud poured into Padas headwaters from high pelting rainfalls of the region.
Sorry, Sabahans you have permanently lost the once awesome Padas to simply elite loggers and their backers.
Kinabatangan – bottom visible once claim
Similarly, the Kinabatangan.
I once asked late colleague, Kassim Sangi, what the river was once like in its upper reaches like Kuamut, he said he could see prawns in the bottom because the water was clear.
Also, Ruth Kong, well known among tourism circle who grew up in Sukau, told me once she could see the bottom Kinabatangan as water was clear.
Segama river – once crystal clear
Also, Dr Waidi Sinun, Group Manager of Yayasan Sabah (Conservation Division) can confirm that he, me, Dr Clive Marsh, I think the late Danny Chew also, rafted down a crystal clear Segama river from tne Danum Field Research Centre where we saw distinctly many arm size fish at the bottom , in 1989, if I am correct.
What happens to the Segama river now?
Turbid, murky, muddy
But like the Padas, we see a muddy Kinabatangan every day, all the time, permanent, no more self-cleansing capacity which has been overwhelmed by the sheer scale industrial plantations and relentless sprawling land use.
Saliu river’s ‘Self-Purification Capacity’ – an eye witness account
But anyway, let’s dive into my refreshing eye witness, where the quick Self Purification Capacity of Saliu river remains very much alive.
All made possible because Murut Tahol village elder, Ansom Putiang, insisted that I go cover the opening of his prided new longhouse infrastructure.
The days were June 13-15, 2025.
The night of June 13, 2025, an unbelievably intense deluge pounded the longhouse at Kg Salinatan, 10 km upstream Pensiangan.
Good sleep!
But next morning, June 14, I was horrified to see a crystal clear river the previous day all of a sudden turned muddy, turbid, murky.
The Wow Factor – Overnight recovery
Honestly, I lost my mood to watch the traditional boat race scheduled for 10am.
I really thought the murky water would linger, and cut a hefty chunk off Ansom’s prided ecotourism/ cultural destination.
But come very early next morning June 15 – Saliu river gave me a really pleasant shock!
It had suddenly turned crystal clear again – muddy waters disappeared!
Wow: I said. It recovers really so fast, in a matter of just one night?
Long lost trust in Sabah’s interest in great rivers, I stood incredulous looking down at it from Anson’s brand new suspension bridge.
A moment of rediscovery
It’s a moment of rediscovery and belief in the vitality and pulse of Sabah’s original rivers - the energetic living nature of water as it flows and nourishes.
The morbid feeling of the Padas, Kinabatangan and Segama’s loss of their original robust selves stripped itself.
Belief in a rivers’ “Self-Purification Capacity” returned.
Even China’s Yellow river was not always yellow in the beginning , as historical evidence indicates it was once relatively clear and simply referred to as ‘the river’ in pre-dynastic times, then turned muddy due to soil erosion intensifying over the centuries partly due to over-farming and over-grazing.
Every river originally has the hidden ability to maintain its natural structure and function in face of degradation so long as so long as a community understands and respects the high functioning natural processes that gives it the ability to withstand and recover from disturbances quickly.
Cynical city folks may satire what good can come out of these simple Murut folks but they ae in for a surprise what these roving report may uncover.
Saliu river’s hidden power to withstand disturbance & recover quickly
So, we ask that inevitable question: What conditions give the Saliu river the ability withstand disturbance and recover overnight from muddy turbidity?
What keeps its “Self-Purification Capacity” so much alive when its more famous peers have been defeated?
Google tells me something - the nature of its headwaters.
Saliu river – which is actually one of the main tributaries that forms the Pensiangan river, originates from the dense, untouched rainforest highlands near the Indonesian border of Indonesian Kalimantan.
So it’s very unlike Padas where its original highland dense forests in Long Pasia had been torn apart.
Where it begins – Old-growth dense rainforests
Saliu river, on the other hand, begins at an Old-growth Borneo primary forest – a mature state that developed over centuries.
Seasoned foresters would always cite the complex structures of primary forests, such as their multi-layered canopies, massive trees, abundant dead wood and leaf litters at the forest floors.
So in this story I deliberately pick s picture of Tham Yau Kong standing in front of a massive belian tree soaring to join a dense canopy 100ft above, in the backyard of Kg Salinatan.
Multi-layered filtration traps top to bottom
Untouched primary forests and headwaters keep rivers clean by acting as a natural, multi-layered filtration systems that trap sediments, absorb pollutants, and regulate water flow.
In addition, the complex root networks of a full primary forest and organic litters hold the soil in place, reducing erosion, while trees which not only shade streams to keep water temperatures cool and oxygen-rich, dense canopies and leaf covers soften impacts of pounding rains on the ground.
In my active hey days on environmental reporting, I had talked to multiple top dog forestry professors like Prof Ian Douglas of Manchester University , hydrology experts foreign or locals, all credit how dense forest canopies soften rain impacts by intercepting precipitation (rain drops falling from clouds) which reduces rain velocity therefore the disturbing impact of its power in motion on soil erosion and surface runoffs, where the canopy acts as a buffer that breaks the force of rain.
Sabah Forestry titans know it, Deramakot tries it
Elite forestry titans in Sabah understand the “Self-Purification” abilities of old complex forest structures when they are not unduly disturbed.
Just visit the 55,507ha Deramakot Forest Reserve of mixed dipterocarps in central Sabah, the chief method used in their acclaimed Reduced Impact Logging (RIL) is designed to avoid destroying this complex many layered forest structure that deliver endless ecosystem services like store carbon, hosts diverse wildlife and maintain climate stability.
There is no doubt about it.
Forests, especially in their undisturbed state often provide the highest water quality, compared to other land covers.
Beware “hydrological hotspots”
Untouched forests are considered “hydrological hotspots” where even a small protected area can disproportionately provide clean, reliable water to a much larger water catchment variously called drainage basin or watershed.
Saliu river is obviously benefiting from hitherto untouched highland headwater forests and down through its course like zealous forest guardians of Kg Salinatan who know they need clean gravity water from a belian studded 500ha ancestral forest they even call “Small National Park”, and protected it from greedy loggers.
From time to time we see the phrase “hot spot” without grasping its deep implication.
When it is used, it actually refers to a specific localised area that experiences ‘a much higher intensity’ of a particular phenomenon that could mean ‘earth quake’, ‘crime’, ‘disease’, ‘flooding’ etc, compared to surrounding area.
It signifies a local point of intense concentration of maybe problems that require focussed attention and solutions.
A song for Saliu like the hypnotic effect of ‘By the River of Babylon’?
Saliu river is fast flowing and navigable by pump boats.
But exactly how long from its highland head water source in Kalimantan to Pensiangan township is still a mystery.
It flows past 12 villages, Kg Salinatan being the most notable.
So far I have been there twice – Dec 3-5 2021, and again, on June 13-15, 2025.
Maybe a musician an compose a song entitled ‘By the river Saliu’ to romanticise its rugged simplicity held dear by the Murut Tahols of Kg Salinatan, just like the hypnotic melodic effect of the world famous pop ‘By the River of Babylon’.
In the December 2021 visit, I talked to village leader Ansom Tutiang, a retired principal of 34 years.
Given its isolation, remoteness from main economic pulse of the State Kg Salinatan basically has “no economy”, most young people had left leaving behind mainly old folks.
So he wondered aloud: What is the future of Kg Salinatan by even a pristine Saliu river.
