Good general overview of backflow preventer, etc. I've read *sprinkler system project* and the good comments there. My question is about a different part of the system. My landscape architect has installed three drip lines. We're waiting until spring to install the plumbing. The previous owner had a sprinkler system that was not maintained for several years. We decided to destroy his hoses, etc., because he did not blow out the lines and they were leaking badly. We still have the 3/4" copper coming out of the city supply but I have not been able to trace where the 3/4" for the previous sprinkler system goes. I don't know what I'm looking for in terms of the plumbing. I know I need some kind of back flow preventer but I'm clueless as to what it looks like. I presume that the previous owner had a backflow preventer but given the crappy plumbing and electrical that I found while doing the remodel, I'm not sure if he had one. Is there some general overview where I can read up on drip systems and back flow preventers and manifolds and timers and god-knows-what else?