http://www.agselect.com/ED/Category.cfm?&DID=11&CATID=1Thiis site even has 'plans' for avian watering systems. I used PVC piping underground with a pressure regualator/washer filter and sysop (backflow) at the outdoor faucet I installed.
Each outside flight has their own valve and also I put a t in some flights to install a kitchen water spray for swings, handwashing etc.. spray the birds etc..
My birds just love this.. be sure to look for the 'parrot drinking valve those are then valves I used.. also I bought stainless steel 1/2 inner hole to install on outside and insdide cage wire. I didn't use any of the tubing due to the heat in florida. I did put installation on each PVC pip up along side the cages.
If I can assist please ask away and good for you to give your birds clean fresh water.. oh , yes, be sure to put drains faucets at the end of the lines. I have three due to my main lines conssist of threee with cage lines running off those three main lines.