KUCHING: Researchers from the University of Nottingham in Malaysia have completed the first phase of a riverbank restoration project in Sarawak that uses natural materials.
The project is being undertaken in partnership with World Wide Fund for Nature (WWF)–Malaysia.
It aims to protect and restore eroding banks along the Trusan River using natural materials, as well as introducing a range of other ecologically–based measures to avoid flooding and erosion in the future.
The work is focused in the section of river near the villages of Long Semadoh and Long Telegan. The people here are almost entirely dependent on rice cultivation, but their land and rice crops are increasingly threatened by a combination of flooding and riverbank erosion.
A team from the University of Nottingham Malaysia (UNM), led by Professor Christopher Gibbins and Dr Teo Fang Yenn, has been working with the local people and WWF-Malaysia to find sustainable solutions to these problems.
An initial hydrological study, undertaken in 2018, allowed the team to identify the causes of the flooding and erosion problems, and to identify a range of solutions based on the principles of green engineering.
The second phase of the work is now underway, involving the construction and testing of various green engineering measures. These extend from using local trees and coconut-coir matting to protect eroding banks, to reinstating natural floodplain wetlands that can help retain floodwaters and limit high flows further downstream.
All the work is being implemented in close partnership with local people; villagers from Long Semadoh and Long Telegan have been playing a key role in selecting the most appropriate methods, as well as installing the bank protection measures.
Gabion installations (large stones contained in wire baskets) were used previously to protect the banks, but due to the high flow forces in the Trusan these did not last long and they also detracted from the natural undisturbed character of the river.
The new green restoration measures were installed over several months last year. The Nottingham team, staff from WWF, and the local people joined forces to do the installation work.
“We are very happy with the work so far. We are all learning a lot, and in fact we will learn both from the successes of the work and from any small failings along the way.
“Of course, our main goal is to use these ecologically-based approaches to help protect the livelihoods of people in the Trusan, but we can also use what we learn from this project to help address similar problems in other remote areas. It is an extremely rewarding project,’’ said Prof Gibbins.
“They were not aware of the bio-engineering approach and they did not know that natural materials from their surroundings could be used to restore the riverbanks. We are grateful to the locals who welcomed us into their town, shared their knowledge, and were open to new ideas,” said Teo.
The teams from UNM and WWF will continue to monitor the effectiveness of green engineering methods, particularly during the monsoon season when water flow is at its most powerful.
If successful, these methods can be rolled out in other areas.
