Integrated flood risk management prioritization in Indonesia

Indonesia has severe flood risk from multiple sources, with average annual loss due to flooding estimated to be 33 trillion IDR (US$2.3 billion). Impacts from severe flooding is significant and a growing concern in Indonesia. Since 2001, on average, flooding results in 260 deaths per year, 14,000 people injured, 1.5 million people impacted or evacuated, and over 283,000 houses flooded. The annual budget managed Indonesian Government for investment in flood management is in the order of 7 trillion IDR (about US $493 million).

Prioritisation of budget expenditure therefore requires understanding of a diverse range of factors, including understanding of available hazard data across multiple flood sources, the distribution of risk at the basin scale, and preferences for equitable distribution of budgets and schemes in the pipeline. In a process of capacity building and training with government technical departments, a range of approaches were demonstrated and applied to a test basin, Bengaman Solo, Java. This included identifying areas of high risk based on different hazards and receptors, using a range of metrics from people at risk to economics, and key services against which to compare proposed schemes. Spatio-economic information on planned investments were prepared in a long-term roadmap as part of the project. It also involved understanding residual risk when different spatial strategies are deployed, and a new National Integrated Risk Analytics (NIRA) tool developed for the Asian Development Bank allows users to introduce a range of mixed measures from nature-based-solutions to property-level-resilience, defences and flood early warning system.

Having explored the use of all these tools a prioritisation process was co-developed and made flexible such that assumptions could be iterated to bring in local knowledge, new data such as climate change sensitivity or subsidence. The outcome has been a process that incorporates the best available hazard and risk data nationally across different sources, supported by a range of steps for which on-line training modules are available.