The river will rise above its banks and flood the surrounding area when more water than the river can hold flows into it.
(The river; will rise; above its banks) (more water than the river; can hold; ) (flood the surrounding area when more water than the river can hold; flows; into it)
The river more water than the river flood the surrounding area when more water than the river can hold
will rise can hold flows
above its banks
into it