"Dams for water storage need to be full. This means that they can't be used as flood mitigation devices."
"Dams for flood mitigation need to be empty. This means that they can't be used as water storage devices."
are you kidding me? dont speak about a subject that you clearly know nothing about....it makes you sound like another science-hating labor voter
as as an actual real-life dams engineer, i will provide you with a technical term that is used in the industry when discussing dams and their capacities to assist you in further dams discussions
Freeboard
go on - go and look it up, see if you can understand what it means
i will save you the bother
Freeboard - 'The vertical distance between the top of the dam and the full supply level on the reservoir.'
i will try to spell it out for you, feel free to ask questions
freeboard - the concept being that although a dam may be 100% full as far as the design operational capacity is concerned....it is not 100% full as you might picture it....that is, the dam is not about to overflow and breach the top of the embankment
travel out to your local reservoir....(do you know where that is? it is the place where the water comes from.....no not the tap, that is where it is delivered from, i mean where water is captured for public use)....and find the dam spillway....(it will be the big concrete thing that looks like an oversized childs slide)....and take notice of the height difference between the top of the embankment of the dam, and the top of the spillway
this several metre differential allows the dam to act as a flood mitigation device, regardless of if the dam is full or not.....if the dam were empty, yes you would have additional capacity available to be used for flood mitigation.....but dams are designed using the conservative consumption that the dam is 100% full when a flood event hits
public safety is of the utmost importance when you are dealing with assets the size of dams, whose failure could result in thousands of deaths, and you will find that many dams are actually designed to pass theoretical 1 in 100,000 year floods
