Rainwater Harvesting in the Marshall Islands

Name of case study

Rainwater Harvesting in the Marshall Islands


Namu, Lib, and Kwajalein Atolls and Islands, Marshall Islands




Suburb/neighbourhood scale

Area / size

40 x 5680 ltr, 10 x 30300 ltr, and 39 x 56800 tanks.

NbS employed

Rainwater harvesting

Type of NbS

Engineered interventions (not using vegetation)


United Nations Development Programme (UNDP) Pacific Office in Fiji, through the Addressing Climate Vulnerability in the Water Sector (ACWA) Project


Green Climate Fund (GCF) and Government of The Republic of the Marshall Islands (RMI) 



Design group


Loading operations in place at Uliga dock in Majuro. Photo: UNDP
Unloading materials from the vessel to small boat to access shallow waters at Lib Island. Photo: UNDP
Climate change benefits
  • Changes in rainfall
  • Drought
  • Flooding
  • Increased temperatures
  • Urban heat island effect
  • Reduced fresh water availability / quality
  • Increased wildfire
  • Wind / storm damage

The Marshall Islands are 29 coral atolls and five islands across an island chain in the Te Moananui Oceania. The county is at extrem risk of sea level rise and regularly floods. As the climate continues to change, powerful storms, flooding, increased rainfall, and storm surges will batter the small island nation. Water scarcity is increasingly problematic, so the implementation of rainwater harvesting systems allows the communities of the Marshall Islands a more reliable water source that can help to sustain them into the future.

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Societal / socio-cultural benefits
  • Disaster risk reduction and resilience
  • Empowerment / equality
  • Food security
  • Freshwater security and quality
  • Waste management and hygiene

The people of the Marshall Islands have been adapting to climate change for millennia. Today and in the future, communities of the low-lying islands will be affected by droughts, rising temperatures, reduced freshwater availability, and sea level rise. The implementation of rainwater harvesting systems is a way to create empowerment over resources, managed by the community, at a time when so much is out of their control.

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Ecological benefits
  • Disturbance prevention
  • Education and knowledge
The tank under installation/construction by the ACWA Team. Photo: UNDP
A KlipTank modular tank set up with no concrete base. Photo: Priority One.

Summary of case study

Over several weeks in July 2023, rainwater harvesting systems were delivered to three northern atolls in the Marshall Islands: Namu Atoll, Lib Island and Kwajalein Atoll. 

Led by the United Nations Development Programme (UNDP) Pacific Office in Fiji, through the Addressing Climate Vulnerability in the Water Sector (ACWA) Project, a team delivered 40 plastic tanks, and 59 flatpack modular tanks, along with 4,770 CMU (Concrete Masonry Unit) blocks, cement, gutters, downpipes, and rain harvesting fittings (UNDP, 2023).

The rainwater harvesting systems were distributed across 15  communities spread across the islands, to improve their water resilience and alleviate the strain on existing water sources. 

The project was helped significantly by volunteers and members of the community, who helped the technical team transport the systems on a boat to the islands.

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The image chosen by the RMI Government in their 2023 National Adaptation Plan because it is the main road of their capital, and is a “clear portrayal of our nation’s extreme vulnerability”. Photo: RMI, 2023.
Rongrong community and RMI EPA staffs pose with the ACWA Team in front of the newly completed Flatpack modular tank. Photo: UNDP

Further resources:

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