How could a river be both a valuable resource and a problem for a region?

A river could be a valuable resource as drinking water for a nearby group of people. A river could also be a problem for a group of people that need to cross the river but have no way to cross it.

A river can be considered to be a natural resource because it provides fresh water for drinking. In addition to this, a large number of people are dependent on them as it is a major source for fishing, irrigation purpose, industries and factories.

Rivers can also turn out to be a problem for a particular region. It is because, during the time of heavy rainfall, the water level in the river rises up, as a result of which it overflows in the inland areas, thereby causes flood, affecting lives, properties, and agricultural crop fields.