Its to allow water levels in the Annagh reservoir to recover.
Irish Water are advising that water restrictions will be in place overnight in Athlone and the surrounding areas.
The restriction will be in place from 10pm tonight, until 6am tomorrow, to allow water levels in the Annagh reservoir to recover.
They say the action is necessary to maintain an adequate quantity of water available to schools, residences and commercial activities during business hours.
They're advising that it can take a number of hours for the water to restore to customers on higher ground or at the end of the network once the water supply is turned back on.