Flooding can be prevented by planning towns and cities in such a way that they take into account the possibility of flooding. This can involve building structures on higher ground, creating designated flood plains, and ensuring that drainage systems are properly designed and maintained. Dumping refuse in drainage channels can actually exacerbate flooding by clogging up the system, while building houses and roads in flood plains can put people and property at risk. Building strong fences around buildings does not directly prevent flooding, although it may provide some protection from the effects of flooding such as debris carried by the flood waters.