Perak’s ‘working river rich in biodiversity’
GERIK: An expedition down the mighty Sungai Perak is a perfect opportunity to see the tranquil interaction among the river, forest and the flora and fauna that thrive there.
It also makes one realise how important it is to preserve nature’s bountiful gifts to the human race.
Sungai Perak, undoubtedly, is the state’s River of Life. An important source of water supply for some 2.5 million people, it is described by local researchers as a “working river rich in biodiversity”.
As with the other rivers flowing in this country, Sungai Perak needs to be conserved well so that it can serve future generations as well.
Fortunately, due to the ongoing conservation efforts of the Perak Drainage and Irrigation Department (DID), the 400kilometre long river – the secondlongest in Peninsular Malaysia after Sungai Pahang – still has relatively good water quality.
According to state DID director Juhaimi Jusoh, the water quality is still good, particularly in the upstream area around Pulau Banding where fish like ikan kelah or mahseer still thrives.
The mahseer is an edible freshwater fish known to be able to survive only in unpolluted waters.
“In the downstream parts of the river, that is from Kuala Kangsar to Kampung Gajah, the water quality level is also relatively good as it’s classified as ‘II A’,” he said.
Rivers or its segments are classified in accordance with the descending order of water quality, with Class I being the best and Class V being the worst, based on the Water Quality Index and Interim National Water Quality Standards for Malaysia.
Juhaimi was speaking to reporters after a four-day Sungai Perak expedition organised by the state and federal-level DID last month.
About 80 university researchers, environmental non-governmental organisation representatives, state and federal DID officials and members of the media participated in the expedition.
Sungai Perak has its origins in the hilly Titiwangsa range at the Royal Belum permanent forest reserve in Hulu Perak. It flows down to Beting Beras Basah in Bagan Datuk before emptying into the Strait of Malacca.
Travelling 130km along the river from Kuala Kangsar to Pasir Salak at Kampung Gajah on speedboats, the participants were able to see the changes to the surrounding ecosystem and water quality as they travelled downstream.
In the upper parts of the river, the water appeared to be in pristine condition, thanks to the forested hills that help to filter out pollutants, as well as act as a barrier to stop the river water from flowing down swiftly and causing floods during heavy downpours.
As the river courses downstream, the water quality takes a dip with its colour taking on an orangish tint – an indication that there were settlements and agricultural activities on the river banks nearby.
Besides enabling the participants to take a closer look at the river and understand the importance of sustaining its ecosystem and safeguarding its water quality, the expedition’s other objective was to provide the researchers with an opportunity to determine which segments of the river required further research in terms of its morphology, cross-section or other aspects.
“We also wanted to look at the issues related to the diversification of Sungai Perak’s water resources,” explained Juhaimi.
Juhaimi said although there were no major problems besetting Sungai Perak, his department was seriously monitoring its sedimentation levels, particularly in the upstream area.
“Land clearing activities at the river’s upstream are causing sedimentation and (if left unchecked) it can have an impact in the downstream area as well,” he said, adding that besides serving as a source of raw water supply, the river water was also used for agricultural activities.
“The only issue we’re facing is sedimentation. If you travel downstream, you will notice that the dumping of garbage into Sungai Perak is not a significant problem.”
Universiti Sains Malaysia lecturer Prof Ismail Abustan, who also took part in the expedition, was concerned about the river’s sedimentation too.
Ismail, who is attached to the School of Civil Engineering and specialises in urban drainage and stormwater management, said the water’s orangish shade as it flowed downstream was not due to pollution but silt deposits.
Concurring with Juhaimi, the lecturer said the clearing of land for rubber and oil palm cultivation in the upstream portions of the river was the main culprit causing the sedimentation.
Forests protect waterways from becoming silted because they have four layers – comprising tall trees; trees that form a thick canopy; epiphytes and parasites that grow on trees; and shrubs, bushes, mushrooms and other small plants that thrive on the forest floor – to regulate the flow of water and sediments into the rivers.
“By cutting down a forest and replacing it with oil palm, only one layer is left. What’s more, the oil palm is planted in rows, whereas in a forest, trees and other plants grow everywhere and they absorb most of the water when it rains.
“See what happened in Cameron Highlands. Forests were cleared for vegetable farms and this led to the nearby rivers silting and causing floods,” said Ismail.
During the recent Sungai Perak expedition, the participants saw evidence of soil erosion taking place on the sandy riverbank at several places.
This, according to Ismail, was a natural process for rivers like Sungai Perak with sandy embankments.
The state authorities, he said, should put limits on the type of boats that ply the waterway and also those used for recreational and tourism purposes.
“Boats that move at high speeds should be avoided as they create strong waves that can cause damage to the sandy banks.
“It will lead to erosion and cause the river to widen. (If left unchecked) the river water will eventually flow into settlements and farms,” said Ismail, adding that the state DID was fortifying the riverbanks by building stone embankments.
Ismail has also been enlisted by DID to carry out a study on the sustainable sand removal capacity of Sungai Perak.
The river is being subject to excavations for sand mining and river deepening purposes, the latter being a flood-mitigation measure.
Ismail has already completed his study on Sungai Perak and his findings show that the authorities have been carrying out their excavation works in a sustainable manner and that the river is in a stable condition.
He is currently carrying out a similar study involving other rivers in Perak.
“The rivers are being excavated (by the state authorities) either to deepen them to mitigate flooding or to mine sand (for the construction industry).
“My study is to find out the quantity of sand that has so far been removed from the rivers concerned and to determine the potential volume of mineable sand. If this (mining) is done in a sustainable manner, the government can continue to earn revenue from sand mining activities and, at the same time, it can check the issue of sedimentation.
Sand mining activities carried out in a haphazard and unsustainable manner can cause the degradation of rivers, as well as erosion of their banks and destruction of aquatic habitats. - Bernama