In message , at 17:17:58 on Wed, 7 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?

A little way up the thread, someone posted a link to an article in
which various experts in the field of dams discussed the Whaley Bridge
problem. One of them mentioned that the drain valves had been replaced
a while ago with ones that were designed to perform a rapid evacuation
of the reservoir if needed.

And we got a bit stalled over the meaning of "rapid". They've been
pumping for a week now.
--
Roland Perry