Originally Posted by Blackcat31:
I get 10 kids undressed, sunscreened, dressed and set up for sprinkler play in less than 20 minutes. They play in the sprinkler for about 60 minutes and then we are dried off, undressed, redressed and have the sprinkler put away all with in another 20 minutes. Easy peasy.... But it might just be the particular group I have right now. Ask this same question next summer and I might totally have a different answer for you. 
Some of my older kiddos will actually come with their swimsuits on under their clothing (and pre-sunscreened too!) in anticipation for a hot day. 
Maybe you could schedule sprinkler days and have the older ones come prepared.
Well done Wonder Woman! I could never get all that done that quickly!
We have water days 2 x a week and the children come dressed in their suits with a bag with their play clothes in it. If we're lucky they have sunblock on too!
Most of them can dress themselves when we come back in. We also take on one more staff person for these days to take care of set up and clean up.