11-20-2007, 11:12 AM
I am planning/designing a 25' stream and pondless waterfall to run next to our deck in Virginia Beach. I spent the weekend moving plants and re-routing some roof drainage that has been giving us some problems and am now trying to figure some details of the design while we are waiting for some good soaking rain so the ground will soften up enough to dig without a jack hammer. We have about 3'+ of fall from where the stream will start to the receiving basin. I hope to use an old well hand pump that has been in the family for a long long time as the start of the stream instead of a conventional waterfall. The two things I’m not sure about are the size of the pump and the size of the receiving basin. I was figuring on about a 4000 gpm pump but not sure what that kind of flow will look like coming from the hand pump. I'm also not sure what size to make the receiving basin. I was "guessing" on a basin about 6'x6' and 2' deep lined at the bottom with some 6" perforated pipe as a storage chamber. I'm not sure how to calculate the area in the voids of the stone along with the pipes to make sure I have enough volume or too much, resulting in more digging than necessary. Any advice on either sizing question would be greatly appreciated. One of the local supply places today were very vague and didn't give me a warm and fuzzy.