Water security in the Welang catchment area
Co-creation and local collaboration
In the East Javan Welang River catchment area, floods are common, which greatly affect local communities. In the process, undesirable effects such as soil erosion, sedimentation and fresh water shortages during droughts occur.
Witteveen+Bos is working in a Dutch-Indonesian consortium on concrete solutions to ensure water security for the local population. This is specifically the case for a number of villages along the Welang: Sidogiri and Sukorejo, where the washing water floods village centres in no time (0.5 - 1.5 metres), sometimes for extended periods of time.
A total of four interventions will take place from September 2023 to August 2024. These include installing four gully plugs upstream. These dams, mostly built from natural, local materials, inhibit the velocity of the water. They also direct some of the flow back to the bank, where it infiltrates the soil as a fresh water buffer.
Downstream, four adaptations will be made in the catchment area around the Kraton Bridge, including a by-pass, a widening and a diversion of the river. ‘This includes the deployment of, among other things, hydraulic modelling to understand the water system. For the integrated, sustainable solutions, we apply the principles of Nature-Based Design,’ says project manager Joost Noordermeer. ‘We are not doing this alone. We train students of a nearby research institute to transfer our knowledge to future Indonesian hydraulic engineers.’
The project focuses on co-creation and collaboration with local knowledge and research institutions and local communities and authorities. ‘The goal is to develop solutions that can be copied to other locations without significant third-party support.’