Water restrictions are being imposed on Inis Oírr, due to the ongoing dry spell.
Starting next Monday, planned restrictions will be implemented on the island from 11pm to 7am.
At this stage, similar measures are not planned for Inis Mór or Inis Meáin but the situation is being kept under constant review.
Irish Water has appealed to people living on the three Aran Islands to conserve water "for the foreseeable future" because of historically low levels for this time of year.
With little or no rain forecast over the next week, the utility says it needs to monitor usage on the public network.
It has asked people to report any leaks they notice, saying this is particularly important given the increased demand on supply over the summer months.
It is the second time in less than a year that restrictions will be introduced on Inis Oírr.
Last August, a major power outage disrupted supply and led to night time cuts to supply.
Irish Water says plans are ongoing to construct two new storage tanks on the island. Tenders for the work are being assessed and a contractor will be chosen in the coming weeks.