Solomon Islands: Honiara Flood Risk Study and Management Plan


Flooding damage, Honiara, April 2014. Source: IFRC

Context and Objectives
As a small Pacific island state, Solomon Islands is particularly vulnerable to natural disasters. Catastrophic risk modelling by the World Bank suggests that the Solomon Islands is expected to incur, on average, US$20.5 million per year in losses due to earthquakes and tropical cyclones.  Honiara is the capital city of the Solomon Islands and serves as its main transport hub and economic, political and educational centre. It is the most densely populated area of the country.  Some 52,000 people are estimated to have been affected by the April 2014 flooding, equivalent to around 10 percent of the population. Up to 80% of the capital’s population were affected.  This includes those who had their properties destroyed or severely damaged, as well as those who lost their livelihoods (for example, through damage to their food gardens).  There was also significant disruption to transport, with key bridges around Honiara being washed away.  Furthermore, some 35% of residents live in informal settlements, which are now spreading beyond the City boundary, often in houses susceptible to cyclones and floods.  This has the potential to increase the risks to the population from flooding, as more people move into flood prone land.

The project objective is to investigate urban flood risk and provide quality information to better manage and reduce flood risks in the greater Honiara area, thereby building and strengthening the city’s disaster preparedness and resilience to weather extremes.

In October 2019, additional funding approved to the project will allow storing the study’s findings in a portal so that data can be easily shared with the government’s specialized agencies (e.g. land use planning, emergency management, and infrastructure development) and by communities affected by flood risk. Training will also be provided to these groups on how to use and interpret the study’s outputs. 

Main Activities and Results

The project is supporting the Government of the Solomon Islands with a study to investigate urban flood risk and provide quality information on how flood risk can be better managed and reduced in the Greater Honiara area, thereby strengthening the city’s disaster preparedness and resilience to weather extremes.

Component 1: Preparation of Flood Risk Study. This component includes the preparation of a detailed flood risk study report, which provides: 

  • A description of the hydrologic and hydraulic analyses that has been undertaken; 
  • A presentation of results showing extents, depths, levels and hazard of design flood events; 
  • A detailed assessment of flood risk in the study area; 
  • A description of the impacts of climate change on flood behavior and risk;  
  • The identification and assessment of flood risk management options.

Component 2:  Planning for future flood risk. This component includes two sub-components: 

  • Investigation of Flood Risk Management Options. 
  • Development of Flood Risk Management Plan.  

Partnerships and Coordination
National and local stakeholders have been widely in the frame of the development of the study to investigate urban flood risk in Honiara.

  • Pacific
Priority area
  • Risk identification and assessment
Window of Action
  • Window 2
Amount approved
  • $500,000
  • $0
  • 01/2015 - 05/2021