Posted: 28/08/2015 at 17:33
It's not normal to empty a pond completely unless you have a leakage problem. You risk disturbing the resident wildlife for no good reason.
You can take out your clumps of iris and reduce them according to your needs......now is probably as good a time as any.
If you really have to empty the pond completely, put all the water and the mud/debris through a sieve..........that way you stand a chance of saving any small creatures but remember, as Fairygirl says, you do need to put a layer of mud back in the bottom of the pond before you re introduce your salvaged creatures.