Can dams resist against heavy flood?

[Finch24]

Hello Guys!

I've an question that can dams helps to stop or reduce heavy floods? There's several studies circulating that dams can't be used for the floods but as a water storing. What you guys think?

 

[bimr]

Many dams are constructed for use as flood control. To reduce flood risk on the Ohio River, the Great Lakes & Ohio River Division operates and maintains 84 dams and reservoirs to protect communities in the region.

US Army Corps of Engineers
Great Lakes and Ohio River Division Website

Constructing and operating a dam affects many aspects of a river and its watershed. Dams can harm the quality of the river's surface waters, habitat in the river, and water flow. There are also potential positive effects of building a dam such as creating an above the dam pool for fish and wildlife refuge during times of low flow. There may also be less scouring and erosion of streambanks because of the reduced water velocity during flood times.

The operators of the dams monitor weather conditions and discharge water so that the dams are not overtopped during flood events.

 

[cvg]

flood retarding structures and debris basin as shown below trap sediment and store floodwater temporarily and are not normally constructed on perennial watercourses. NRCS has constructed literally hundreds of these across the United States

https://www.nrcs.usda.gov/wps/portal/nrcs/detail/tx/home/?cid=nrcs144p2_003199

https://dpw.lacounty.gov/des/Design_Manuals/DebrisDamsBasins.pdf

 

[JedClampett]

Dams are designed for water up to and over their emergency spillway. I guess it's possible to overwhelm the spillway, but those are usually designed like a brick outhouse. If more water goes over the spillway than the downstream facilities can handle that's another issue.
Hoover Dam was designed for flood control, although they do mention electrical generation in the linked article. They're very clear on that on the tour. You couldn't sell it if it was designed for recreation, etc.