A famous Canadian quinquennial event has arrived, and citizens all over the country are required to take note.

Census 2011 is underway, and information has started arriving in mailboxes around the country. Canadians have the opportunity to contribute information, which will have considerable impact of decision-making at all levels of government. The national census is conducted every five years by Statistics Canada.

Peter Liang, Census Communications Manager for B.C. with Statistics Canada, says this year's census includes two significant changes.

"For the first time, 60 per cent of the households in Canada will receive a letter in the mail - as opposed to the traditional paper questionnaire," Liang said. "The letter will invite the household to complete the census online. It's a secure, convenient and fast way of completing this legal requirement."

Liang said that some people will still receive the traditional questionnaire, but they can still complete it online. The questionnaire and the letter will have a central access code that people can use to go online and do their form there.

It is important to note that the 10-question census is mandatory. Citizens are required by law to fill it out.

"The census itself has 10 questions, concerning age, sex, marital and common-law status, family relationships and language," Liang said. "Canadian households are legally required to complete the census form. It's short and simple - only takes a few minutes."

However, the other change that has been introduced is that the previous long-form census - which was also mandatory, has been replaced by another survey which is not.

"Roughly four weeks after the census, in late May or early June, one in three households - about 4.5 million - will also be asked to take part in the new voluntary National Household Survey (NHS), which has replaced the previous long-form census," Liang said.

While the NHS may be a voluntary survey, the information gathered from it is extremely important, Liang said.

"Unlike the census, Canadians do have the choice to complete the new NHS questionnaire - it's voluntary. But we strongly encourage everyone to complete it. The reason being, the census only has 10 questions. The National Household Survey, on the other hand, will collect information, such as immigration, ethnic origin, education, income, religion - information that's really critical for communities to make decisions. We are asking Canadians to recognize that, and to response to the survey if they're among the one-in-three sample."

The census and the NHS are the only chance in the next five years to gather information that communities need for decision-making, "information that will impact every citizen in that community," Liang said. He cited labour markets as an example, saying the survey is "the only source for labour market information for communities like Cranbrook.

"The importance of the census itself goes without saying," Liang said. "It affects transfer payments, for example. The federal government, based on the census counts, decides on the amount of transfer payments to the provinces, and from the provinces to the different municipalities such as Cranbrook. For the fiscal year of 2010-2011, British Columbia will receive roughly $1,200 per person, based on census count. And also, we've just had an election, so the 2011 census will actually determine the number of seats that a province will have in Parliament, or the boundaries of ridings."

The first results of the census - population and dwelling counts - will come out in February, 2012, Liang said. The rest of the data will be released gradually over time.

More information on Census 2011 can be found at www.census2011.gc.ca. And Liang said if people need help with filling out the form, there is a census help-line, open from 8 a.m. to 8 p.m. local time, 1-877-777-2011.