Observed adaptation during drought events includes community water sharing  as well as using alternative water resources such as water purchased from private companies , desalination units  or accessing deeper or new groundwater resources . Rainwater harvesting to adapt the water supply system in the Kingston Basin in Jamaica was able to significantly alleviate water stress, for example. Still, it would not fill the total supply gap caused by climate change . Likewise, groundwater sustainability with increasing climate change in Barbados cannot be ensured without aquifer protection, leading to higher optimised food prices if no additional adaptation measures are implemented . The potential of using multiple water sources is rarely assessed in future water supply projections in small islands . In the Republic of Marshall Islands, more than half of all interviewed households have already had to migrate once due to a water shortage . In Cariacou, Grenada, increases in migration rates have been observed following drought events . with long-term cross border and internal migration shown to be having significant impacts on well-being, community-cohesion, livelihoods and people-land relationships .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report