What happens to sandbags after floods?

So the Red River once again is rising in Manitoba and the in states south of it, so once again the news is full of volunteer lines of people moving sandbags to places where they hope to stop the water from going into. But when the flood is over again, where do the sandbags go?

Oddly enough, you can get a ready answer to this question by just googling it! See this news item.

Or, this news item from last July describes how in the U.S. the people who lose their source of income after the flood can get temporary jobs removing the bags that were put in front of the restaurants they used to work at.

The bags are not burlap anymore, they are made up of a plastic that does degrade. After a "few weeks" of exposure to sun they will break down, so you could have a pile of sand on your hands if you don't work fast to remove them.

So you can reuse the sand for gardens, gritting the path in the winter, or mixing into concrete, but some of it does end up in landfill. Great, spend time and effort getting the sand out of the ground and into bags, then put it back in to confuse future archaeologists when they find layers of sand in the ancient dumps. "The ancient people seem to have been wiped out by a desert of sand that covered the planet around the year 2000 A.D."