Integrated Urban Resilience Sector project in Tonga

Adli Wahid, Unsplash
Area characterisation: 

Tonga's population is estimated at 100,745 inhabitatns. Nearly three quarters of Tonga's population resides on the main island of Tongatapu and 80% of the island's population and critical infrastructure are found in low-lying coastal areas. These areas are with an average altitude of 2 to 5 meters and so they are also more exposed to sea level rise, storm surge and tsunami inundation, and to the increasing frequency of floods. Some climate models suggest that without strong and rapid climate action, most of present-day Nuku'alofa could be underwater by 2100. 


The Urban Resilience project aims to supply flood management, sanitation and water infrastructure, a major resilience and a climate strategy to the most vulnerable households.

Potential impacts/benefits: 

The project's flood management will reduce the incidence of floods and the related repair costs for both households and businesses. Drainage systems will help improve the resilience of 40 hectares of land in seven flood-prone locations.
Improved sanitation conditions will reduce exposure to waterborne diseases and improve water safety for residents. The improvement of the conveyed distribution networks will guarantee a reliable water supply to 99.9% of the population.
The introduction of a long-term and community-wide disaster risk management program will help protect those most vulnerable to the impacts of climate change and will increase the resilience of the urban area.

NbS benefits 
  • Flood peak reduction
  • Reduce flood risk
  • Reduce load to sewer system
  • Reduce risk of damages from drought
  • Developing climate change mitigation
  • Improve connectivity and functionality of green and blue infrastructures
  • Increase quality and quantity of green and blue infrastructures
  • Enhancing sustainable urbanisation
  • Improve water quality
  • Increase well-being
  • Provision of health benefits

The projects is supported by an US$ 18.27 million from the  Asian Development Fund grant.

Further information

Sustainable Development Goals 
  • 3. Good Health and Well-being
  • 6. Clean Water and Sanitation
  • 10. Reducing Inequality
  • 11. Sustainable Cities and Communities
  • 13. Climate Action
Key Performance Indicators: