With global climate change comes an increased threat of urban flooding to many towns and cities.
In Jakarta, Indonesia, urban flooding is a very real problem.
With a growing population consuming more water, an increase in land covered with cement or concrete, a decrease of natural green spaces and a changing climate, Jakarta has to deal with the triple threat of flooding, water shortages and land subsidence.
According to Sutopo Purwo Nugroho, Head of Data, Information, and Public Relations in Indonesian National Board for Disaster Management (BNPB), as much as 85% of the rainwater is converted into surface water instead of groundwater, as concrete covered land stops rainwater from being absorbed into the soil. To adapt to climate change, the Jakarta administration is building a drainage system consisting of vertical cylindrical holes some 10cm wide by 100cm deep, throughout the city using BIOPORI.
First invented by Dr Kamir R Brata a researcher from the Bogar Institute of Agriculture, the BIOPORI or Biopore Infiltration Hole, in a water absorption method which is used to reduce the flood effect by increasing the water infiltration to the ground.
“Biopore” are naturally occurring holes or small tunnels formed underground from the activities of worms, termites, plant roots, etc. Biopori was originally designed as a water catchment area. However, it soon became clear that it was a perfect solution to reducing the excess of surface water that causes flooding, fertilize the soil, manage organic waste and at the same time save water.
Once Biopori holes are dug homeowners are encouraged to place their organic waste in the soil holes to produce compost which is what then feeds the soil fauna such as worms. They then create pores in the soil which will easily absorb water and eliminate surface water and flooding whilst reducing greenhouse gasses CO2 and methane.
In 2014, the President of the Indonesia Global Compact Network (IGCN) YW Junardi launched a campaign for 1 million BIOPORI holes to be installed across Jakarta.
To date, the administration has built 761 drainage systems, out of the target 1,000 for this year, but it needs 1.8 million to be installed to achieve a flood-free city and is calling on its citizens to install their own Biopori holes on their land.
In Bandung, Indonesia, The Million-Biopori Infiltration Hole Programme was launched by the Mayor of Bandung, and to date has made some 3000 infiltration holes.