The latest water consumption figures from the Central Statistics Office show that the average daily water consumption for metered households was 383 litres a day.
However, this figure has been skewed by a small number of households which used very large amounts.
The figures show that just 0.3% of metered customers used 12% of metered water. 3.4% of users accounted for 31% of all metered water.
The median figure for all households, which is less sensitive to such distortions, was 252 litres a day.
The figures apply only to houses with domestic meters.
In January 2015 there were 519,781 households in the state with meters. By December 2015 that figure had risen to 771,348.
The target for domestic meters was set at 1.4 million so by December around 55% of households had meters.
The CSO also gives a breakdown by month and by geographical area.
March 2015 saw the highest consumption for that year with metered households consuming an average of 402 litres a day (median usage 258l/d) while November saw the lowest with average daily use at 368 litres (median usage 241l/d).
On the geographical breakdown Kerry and Tipperary had the highest average annual figure of 430 litres per day, while Cavan had the lowest at 288 litres.
In Dublin postal districts the Dublin 2 area had the lowest annual average of 283 litres per day while Dublin 6 had the highest at 488 litres.
Dublin 6 saw a decline over the year from a monthly average in 516 in January to 455 in December.