Average monthly consumption ranged from 368 litres to a high of 402
Figures show the number of domestic water meters increased to 764,319 by December 2015.
This is compared to just 519,781 in January of the same year.
The Central Statistics Office (CSO) say the average consumption per meter per day in 2015 varied from 274 litres to 383 litres.
It says the average monthly consumption ranged from 368 litres per meter per day in November to a high of 402 litres in March.
Cavan had the lowest average consumption in 2015 at 313 litres, compared with Kerry and Tipperary which had the highest annual average of 430 litres.
Cavan also had the lowest monthly average of 288 litres in March 2015 while Longford had the highest monthly average of 474 litres in June.
In the capital, the Dublin 2 area had the lowest annual average daily consumption figures at 283 litres per meter per day.
Dublin 6 had the highest average daily consumption at 488 litres in 2015 - although the monthly data for this region shows a gradual reduction in usage from 516 litres in January to 455 litres in December.
Around 69% of total water consumption by domestic metered customers in 2015 was accounted for by 96.6% of customers using a threshold of 1,000 litres per meter per day.
At a higher threshold of 10,000 litres per meter per day, 88% of total water consumption was accounted for by 99.7% of customers.
This left the remaining 0.3% of customers accounting for 12% of total water consumption.
Comparing 2014 and 2015, there was a small increase in average consumption from 381 in 2014 to 383 litres per meter per day in 2015.
The CSO notes: "There was a substantial meter installation programme during 2015. This did not happen concurrently in all counties.
"In a small number of cases, we have excluded all data for a county for a month because there were only a small number of meters installed e.g. county Cavan in January and February 2015.
"Similarly there were a relatively small number of meters installed in Dublin 17 and Dublin 24.
"The consumption levels in these two postal districts was considerably higher than elsewhere and considered to be not representative of all households in the two areas."