Conserve water through rainwater harvesting system

Dr Chong Meng Nan - School of Engineering

Having experienced a prolonged water rationing exercise last year, water conservation, rainwater collection and greywater recycling have become a keen interest of many Malaysians.

At Monash University Malaysia’s School of Engineering, senior lecturer Dr Chong Meng Nan is researching the effective use of rainwater harvesting and other alternative water systems in urban areas for residential, commercial and industrial developments.

Rainwater harvesting system collects roof water for non-potable purposes, including toilet flushing, washing machine, irrigation and other general cleaning uses. With proper treatment, rainwater can also be extended for potable purposes.

Dr Chong, whose research interest is in green technology, said his role is to look at whether the system is safe, economical and engineering feasible to sustain over a certain period of time.

“We also look at the amount of water that can be saved and how to implement such a system in different climatic conditions, which is a challenge of our research,” he said.

Dr Chong, who was a research engineer and project leader at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia, said his motivation to do research on rainwater harvesting system is from his exposure to urban water research at the institute.

He said even though Australia had implemented rainwater collection for years, a similar system would not be suitable for Malaysia, where the amount of rainfall is much higher and intense.

“The average rainfall in Adelaide is 700mm per year and 1,300mm in Brisbane.

“If we use the same system in Malaysia, where the average rainfall is 3,000mm per year, it will cause potential flood to properties,” he said.  

Apart from looking at the system, Dr Chong said he and his research team members are also monitoring rainwater quality samples from different areas in the Klang Valley.

“We want to see how dirty the rainwater is and what treatment system we would need to put in place to ensure cleanliness and safety even if you accidentally consumed raw rainwater without proper treatment,” he said.

He said undesirable materials like heavy metals and bird droppingswill get into the rainwater collected and when it is stored in the tank, may cause diseases when the rainwater is used.

“A proper disinfection method will have to be incorporated into the system to prevent microbiological contamination,” he said.

While it is easy to install a rainwater harvesting system for residential, commercial and industrial properties, Dr Chong said its maintenance and sustainability are still barriers to implementing such a technology.

“There have been initiatives to adopt green technology, there are still a lot of gaps that need to be bridged.

“There are companies that build the system but it just gets abandoned without proper maintenance as there is a lack of competent workers to do the job or companies that offer such a service,” he said.

He said financial incentives are needed to encourage members of the public to install and maintain the system so that we can conserve water and preserve our environment.  

For more information on the programs at Monash University Malaysia’s School of Engineering, please visit