Final Answer:
Three examples of structures used to hold back flood waters are Dams, Levees, Floodwalls.
Step-by-step explanation:
Dams: Dams are versatile structures that serve multiple purposes, including flood control. They can impound water during periods of excess rainfall and release it gradually, preventing downstream flooding.
Levees: Levees act as protective embankments, raising the height of riverbanks to contain water within the natural channels. They are effective in preventing overflow and safeguarding adjacent areas.
Floodwalls: Floodwalls provide vertical barriers to impede the flow of water and protect against flooding. They are often used in urban areas where space is limited, providing a concentrated defense against rising water levels.
These structures play vital roles in managing and mitigating the impact of floods, safeguarding communities and infrastructure.