In our community garden we have no access to downspouts for rain water collections. Any ideas for other sources of collection?
If you have a fence, a sheet of plastic and some 5-gallons buckets or clean garbage cans, cut the sheet of plastic into lengths about 1.5 times as wide as your container. You will have to see what the length should be when you put it together. Clothespin the short edge securely along the top of the fence, draw the rest of the piece out at an angle (to catch the water), set the 'tail' of the plastic in the bucket, and set a large, smooth rock on the end of the tail to hold it down (otherwise, the wind will blow it out).
While more horizontal plastic will catch the most rain, it will also tend to catch it and hold it, sagging between the fence and the bucket. You will need to experiment just how long and at what angle is best.
Otherwise, if there is a shed or building nearby, see where the water pours off the roof and put a garbage can under it.
If you do have some kind of structure, contact a local guttering company and explain the problem. Not only do they install new gutters, they have to remove and discard all the old guttering. Maybe they can pick out a few decent pieces and you can install them.
I'd check out Brad Lancaster's Rainwater Harvesting for Drylands and Beyond, Volume 2, Rainwater Harvesting Earthworks. It talks about how to store the rain in the ground, with no needed cistern tanks, tubing or collection surface, other than the ground. The book has lots of variations on the theme depending on your particular situation. Brad's website itself has a lot of information.
Though I haven't read them, there are several books out there on rain gardens with probably similar ideas.
Here is a link that might be useful: Harvesting Rainwater Website