Galway County Council has said the amount of water used during the cold snap increased by between 30% and 50%.
Water supplies are being affected by poor pressure and, in some cases, a loss of supply.
Areas serviced by the Ballinasloe Regional Water Scheme including Clonfert, Clontuskert, Eyrecourt, Laurencetown, Kiltormer and Clonlahan are worst affected.
Water tankers are being provided and consumers are advised to boil all water before use.
The Council said the overuse is largely due to taps that have been left running. It is urging householders to conserve water where possible.
