"Tim+" wrote in message
...
Roland Perry wrote:
In message , at 21:17:49 on Tue, 6 Aug 2019,
NY remarked:

The one thing I've not seen mentioned anywhere is whether they have
been emptying the reservoir by the normal route (valves draining into
canal system) in addition to the much-publicised pumping operation. I
presume they have, but it's not (that I've seen) been mentioned.

Exactly. Have they decided not to, or has it just escaped the attention
of the civilian press?

Well it would beggar belief if they *havent* opened the normal drain
valves but I imagine that theyre not designed to empty a reservoir
quickly. After all, if you have a working spillway why would you need a
humongous drain valve?

Because spillways dont allow you to empty the reservoir.

And plenty of spillways dont allow you to empty the reservoir
and you can need to do that quickly with some dams which
can end up with a lot of new water in massive downpours.
https://www.youtube.com/watch?v=aX_efvvsyWg

Of course if your spillway fails then youre in deep trouble but I guess
thats such a rare event mega drain valves arent built into reservoirs as
a routine.