Good idea, Dave!

You might could get a small 8' Intex pool ($45), like this:

backwash INTO it, let it settle, siphon the clear water back into the pool, and dump the leaf sludge onto your garden. You could even buy the pump ($30) and use it to put the water back into your pool after the gook settles.

(Just love how they show ALL THAT ROOM in a tiny 8' OUTSIDE DIAMETER pool! But, it holds 600+ gallons, which is more than enough for you.)