Central Otago District Council water services manager Quentin Adams said water use followed a simple pattern in the district - when it rained more, people used less water to irrigate their lawns and gardens.
But the drop from the spring-summer period of 2017 to 2018 was remarkable, especially when a gradual increase in residents, visitors and new buildings in Central Otago meant more water would normally have been needed, Mr Adams said.
In the combined Cromwell and Alexandra district, 116mm of rain fell from October to December 2017, and 198mm fell from October to December 2018, he said.
In Cromwell, 772,063cu m of water was used from October to December 2017, compared with only 498,817cu m from October to December 2018.
In Alexandra, 504,182cu m of water was used from October to December 2017, compared with only 328,665 from October to December 2018.
Mr Adams said the data ''clearly'' showed the ''direct impact'' rainfall had on water usage.
-The Teviot Valley is the last area in Central Otago to have water meters installed.
About 500 meters have been installed in Roxburgh and Lake Roxburgh over the past 18 months.
The first billing cycle will begin in March and customers will receive their first bill in September.
