It follows disruptions to the system last night also.
Irish Water customers in Westmeath are facing a second night of disruptions to their supply.
The restrictions are being put in place in Athlone to allow water levels in the Annagh reservoir to recover following a mechanical failure at the water treatment plant.
The ulitity says it's necessary to ensure customers have a water supply to their homes and businesses during the daytime.
More details can be found on Midlands 103.com