For example, building a dam or levee may protect a community from the small- and medium-sized floods the structures were designed to handle.
(building a dam or levee; may protect; a community; from the small- and medium-sized floods) (the structures; were designed; to handle) (the small- and medium-sized floods; to handle; the structures)
building a dam or levee the structures the small- and medium-sized floods
may protect were designed to handle
a community from the small- and medium-sized floods
to handle
the structures