Shouldn't really be a problem. Just revomve the sawdust. If it keeps doing it then leave it to it. Just move the food and water to a place it will have access to them. It will probably be bored of it after a few days and stop doing it.
my kids hamsters all do this. they move there bedding around quite frequently. you will probably find some food hidden in there too. I tend to leave it alone unless the tubes get really blocked