Natural methods to control water flow
There are a number of nature-based solutions used for retaining or diverting surface runoff, especially during a downpour.

One of them is “earth swale”, which refers to a landscaping technique used for water management and conservation, said Housing and Urban Futurist Resilient City consultant Mustapha Kamal Zulkarnain.

“A swale is a shallow, often gently sloping and vegetated channel designed to manage and control the flow of water.

“The earth swale method involves creating these channels on land surface to effectively direct and slow down the movement of water, allowing it to be absorbed by the soil rather than having it quickly run off.”

Earth swales are commonly used in sustainable landscaping to manage water in an eco-friendly way, preventing water wastage and promoting healthy soil and vegetation.

They can be implemented in various environments, from residential landscapes to agricultural or natural areas as well as urban developments.

Another technique is bioswale.

“Bioswales are parts of sustainable green infrastructure that can manage stormwater runoff by filtering pollutants and replenishing groundwater, said Universiti Malaya Associate Professor Dr Melasutra Md Dali.

She said vegetation and soil were used to slow, filter and absorb rainwater, reducing the strain on traditional drainage systems and helping to mitigate flooding and soil erosion.

The integration of bioswales into urban landscapes promotes environmental sustainability and enhances community resilience to climate-change impacts, Melasutra said.
There are a number of nature-based solutions used for retaining or diverting surface runoff, especially during a downpour.