When it rains, let it be harvested

What are the possibilities for reusing stormwater run-off as a direct source of water supply?
Canada’s National Research Council Centre for Sustainable Infrastructure has begun researching the question by studying two urban stormwater retention ponds in Regina to see what the quality of the water is and whether it could be treated for certain non-potable uses. For example, the water might be used domestically for cleaning, toilet flushing, laundry lawn-sprinklers, etc.
The second phase of the studies will evaluate different technologies available for treating the stormwater to make it usable.
A report in the NRC’s Construction Innovation newsletter notes that in other parts of the world where water is in short supply, municipalities have adopted policies called Integrated Urban Stormwater Management (IUSM) to harvest storm water for sub-potable uses. However, Canada has been slow to take up the challenge because water here is generally readily available and cheap.