Water audit reveals demand in downward trend

NANAIMO – City’s first water consumption audit shows more can be done to prevent revenue loss.

Nanaimo’s daily water consumption rate for both personal and industrial use is better than previously thought, but more can be done to prevent revenue loss according to the city’s first complete water audit.

In 2012, it was estimated that each Nanaimo resident averaged 296 litres per day, while the total commercial, industrial and residential consumption totalled 530 litres per capita every day.

The audit, commissioned to better understand water demands in the city, revealed Nanaimo residents on average use 251 litres per day, below the provincial average of 353 litres per day and national average of 274 litres per day.

The city’s total commercial, residential and industrial average water use is 492 litres per day, which is also below the provincial average of 606 litres and national average of 510 litres.

“Over the last seven years the peak demand has been in a downward trend,” said Euan Wilson, a water resources technologist who spearheaded the audit. “So we’re doing well to conserve water. The average demand is also in a downward trend but not as steep. It’s interesting to note demand is dropping even though we had an increase in population of 6,672 people during that seven-year period.”

The study also found that Nanaimo’s 620 kilometres of water supply and distribution piping is considered tight and well maintained. It also identified leakage, the result of pipe breakage, at less than 10 per cent, which is lower than most Canadian municipalities.

Wilson added that while Nanaimo’s numbers compare well to the rest of Canada, on an international standard usage is still considered relatively high.

“We’ve got a lot of work to do if we want to compare to a country like the Netherlands, which has an average daily residential usage of 124 litres per day,” he said.

According to the study, Nanaimo’s water balance consists of 51 per cent residential usage; 21 per cent commercial, institutional and industrial use; 15 per cent municipal use; 10 per cent leakage; and three per cent metering errors. Only the residential, commercial, institutional and industrial usage generates revenue for the city.

The audit also found the city’s bulk water meters are accurate, but 50 per cent of large industrial and commercial meters are oversized and under record low flows which results in lost revenue, and that residential meters, which have an average age of 14 years, are 97.8 per cent accurate.

Those meters lose accuracy, and as a result revenue for the city, beyond 24 years of age.

“An inaccurate meter benefits the homeowner,” said Wilson.

Recommendations stemming from the audit include updating city engineering standards to correct large diameter (industrial and commercial) water metres; allocate funding to replace older residential metres and oversized larger commercial and industrial metres; and undertake future audits to monitor consumption and revenue losses.

In 2007, the city adopted its water supply strategy with the three principles of the strategy focusing on providing safe drinking water, to ensure a sustainable water supply and to provide cost-effective delivery.

In 2008, a water conservation strategy was adopted by city council, and the recently approved Corporate Strategic Plan identifies water as a top priority for Nanaimo and its residents.