These are fairly complex questions. Indeed, data on water availability and usage in Canada is not as comprehensive as we would like it to be. However, Statistics Canada has examined or is currently examining water usage by industry, farmers and average citizens. Our ability to collect this kind of data is limited and the process is complex and costly. Without water meters, it is difficult to know how much water households use.
Basically, all we can do is divide the amount of water that flows out the plant by the population supplied. However, we know that up to 40 per cent of the water treated can be lost in municipal systems, which means that estimates are not necessarily very accurate.
Statistics Canada compiles data on the availability of water, rainwater and runoff water, in cooperation with Environment Canada, and data on groundwater, in cooperation with Natural Resources Canada. Collecting data on groundwater is not necessarily a federal responsibility,as nowhere is this stipulated in the Constitution. However, most provinces are very happy to see the federal government step in and cover the cost of gathering this data.
Of course, more data is still needed. A group at Statistics Canada is attempting to establish a record of water availability and usage and to understand where our water is going. However, this is a fairly complex issue.