Nature based technologies that stops flooding and cleans up contaminated water

Known as Indonesia’s ‘rain city’, Bogor receives 3,000mm of rain per year. In the Colonial-era, irrigation channels were designed and built to transport runoff to rice fields that encircle Bogor. But with houses now replacing most of the city’s agriculture, the runoff  from heavy rains causes flooding in Bogor, as well as downriver in the nearby metropolis of Jakarta.

Urban Water cluster research has been addressing how innovative, nature-based solutions such as ‘rain gardens’ can help to keep waterways free from pollutants, stop flooding and create green, beautiful and cool spaces.

Rain gardens look similar to a normal garden, but beneath these green urban spaces are sandwich layers of sand, gravel, roots and microbes through which polluted water passes and clean water exits, which can be used for irrigation for urban agriculture or household washing.

“Rain gardens not only keep our precious waterways free from contamination, they are beautiful to look at, provide habitat to local wildlife, use very minimal energy and are easy to maintain,” says David McCarthy, Associate Professor in Water Engineering in Department of Civil Engineering at Monash University.

Professor Hidayat Pawitan of Institut Pertanian Bogor and Dr Dwinanti Rika Marthanty of Universitas Indonesia are working with David and his team, Dr Emily Payne and Dr Harsha Fowder, to explore how green technologies using nature based solutions could apply to communities in Bogor.

“Rain gardens, constructed wetlands, swales, green walls, green roofs, porous pavements, detention ponds, rainwater tanks and sedimentation ponds are all possible green infrastructure options that could be incorporated into city plans in Indonesia. By conducting workshops in Bogor we bring together experts in biofiltration and green infrastructure, to explore which of these nature based solutions best suit the different urban environments in Bogor” says Harsha.

The cluster aims to create a guide for green infrastructure application in Bogor that will inform the design of water sensitive urban plans and, more broadly, the strategy to leapfrog Bogor Raya to a more water sensitive and resilient future.

“We aim to change the paradigm of urban water management in Indonesia using the water sensitive city concept”, says Dwinanti. “By incorporating green infrastructures into spatial planning and urban designs to manage rain water quantity and quality, as well as aesthetic aspects, we will help to promote environmental awareness and values and conserve the rivers and groundwater recharge areas of Bogor without sacrificing regional incomes”.

Professor Hadi Susilo Arifin (IPB) agrees and sees the cluster playing a critical role in educating communities in the sustainable water practices.  “Most communities in Indonesia have low levels of environmental education so they treat rivers as garbage bins. Perhaps when they are filtering water themselves and using it to grow cash crops that make them income, they will appreciate clean water more,” Hadi says.