Residents of Metro Vancouver have been using less water per person on a steady basis for the past decade – a trend that means the region may be able to delay expensive new projects to increase water-supply capacity.

"If the consumption patterns continue, it does defer some of the spending we might have to do, projects that would cost billions," said City of North Vancouver Mayor Darrell Mussatto, who is chair of the utilities committee at the region's governing body.

That's good news for the region, although it still doesn't break any records for low water use among Canadian cities; many people believe there's no need to conserve when it rains eight months of the year. The cost of delivering water here, for the approximately half of homes and businesses that are metered, is also cheap, because it's a gravity-fed system.

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If Vancouver residents had continued to use the same amount of water as in the past, the region would be facing the prospect of having to build a second intake for the Coquitlam reservoir, one of the three in the region, or raising the height of the dam at the Seymour reservoir.

Both of those projects, which were being envisioned for construction within a decade, would cost hundreds of millions of dollars. They might now be delayed for 35 or 40 years, said Mr. Mussatto.

He and Metro's director of policy for water services say that Vancouverites have become water savers for a number of reasons.

For one, the region has been building more multifamily housing every year than single family.

"Densification definitely does reduce the per-capita demand, because of lot of residential water goes to outdoor uses," said Inder Singh, the director.

As well, new building codes have required – and conservation-minded consumers have chosen – new water-efficient fixtures: toilets, showers and washing machines that use less water.

Metering is also increasing in the region, and seeing the price of water on a bill motivates people to use less.

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The news about the continuing decline in per-capita consumption comes at the end of a summer when Metro Vancouver issued several warnings to people about saving water, even though the weather wasn't particularly hot, unlike the 2015 summer.

A report going to the utilities committee Thursday shows that about 60 per cent of water in the region is used in residential areas and that usage by all sectors has been declining since 2006.

A presentation earlier this year from Mr. Singh shows a 20-year overall drop, with spikes along the way, in the region.

In 1985, there were about 1.3 million people living in the region, using about 1.9 billion litres of water a day. In 2015, after the population had risen to 2.4 million, overall water consumption was down to less than a billion litres a day.

Mr. Mussatto said one perception that he has to fight is the belief that there's no need for water conservation in an area defined as a rain forest. No matter how much rain falls in Vancouver, he said, there are dry months the region has to get through. And the more water people use, the more reservoir capacity is needed to make sure there is enough for the driest summer.