On Thu, 8 Aug 2019 06:20:01 +1000, jleikppkywk wrote:

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.

The canal system isn't built to carry large volumes of water. The
spill ways around locks are tiny, they only have to deal with a lock
full of water every five minutes or so.

Peak Forest Canal locks are roughly 22 x 2.25 x 4 m call it 200,000
l. At the start the 16 Fire and Rescue service high volume pumps
could shift 112,000 l per *minute*. The larger pumps in place now I'd
say they are shifting 500,000 l min or more. 2+ locks worth every
minute...

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

The need to bring the level down quickly means pumps, though I
wouldn't be surprised if the media haven't noticed or even thought
about the canal. But in the big scheme of things the amount of water
you could release that way is not much more than a gnats pee in a
pint of lager. The brook at the bottom of the spillway drains into
the River Goyt.

Well it would beggar belief if they *haven t* opened the normal
drain
valves but I imagine that they re 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 don t allow you to empty the reservoir.

Aye, there to set a maximum level in the reservior.

--
Cheers
Dave.