Hey, folks,
I've made a number of garden ponds over the years, and most of them have been rectangles. I did have a naturalistic irregular curved edge pond in Western Pennsylvania, but in California, Texas, Tennessee, Mobile, and here inside the beltway, I've always done rectangles. Because liner comes in rectangles, and it's expensive, so I always want to make the pond as large as possible, without wasting any. Besides, I've always used wood frames: dig the hole, frame it up with 2x4s or 2x6s, attach the liner to the frame, and trim it up with strips of wood. It works well. Add a filter next to it, let it gravity flow back into the pond, and life is good.
But then, the other night, I sat down the household, which at this point consists of me, my Darling Bride, and #6 son, and discussed plans for the back garden. Among many other things, the plan calls for two ponds. I already have the liner for the first one, 15 x 20, so that'll make a nice wood framed pond, somewhere around 9 feet by 14 feet, and 3-4 feet deep, depending on how I slope the sides. I'll do a variant on the sand and gravel filter on it. No problem.
Then I started talking about the other pond. The main one. I've got my eyes on a 20 x 25 foot liner for it. Figured I'd build it like I usually do. Then Darling Bride, who almost never gets involved with outside things, said "Maybe you should make a natural edge pond." And thus spake She Who Must Be Obeyed!
Now, she's New England Frugal, so when I explained that would waste some liner, I figured she's relent. She did nothing of the sort. Instead, she doubled-down. "That part of the yard is on a slope," she said. "Can you add a stream?" I tried to explain that would raise the costs. I swear to goodness: aliens kidnapped my Darling Bride, and replaced her with a look-alike who doesn't squeeze every dollar until the eagles grin!
A couple days later, I decided to test the alien kidnapping theory, and took her to the local stone yard. Sure enough, they had a bunch of pallets of what they called Pennsylvania Wall Stone. Just the kind of fairly flat, irregular rounded edge stone one would use to hold down the edge of a liner. She found a pallet with a color she liked. Seeing my chance to test the alien replacement theory, I showed her the price tag: $249 dollars. She didn't blink. "Who are you," I said, "and what have you done with my Darling?"
So I'm in for it now. You need to know a couple things. My soil is rocky clay, full of roots. The whole yard is on a bit of a slope, and when it rains the water follows down the layers of clay and comes to the surface, as an intermittent spring, in the fairly flat area where the pond will be. About 20 feet uphill from the pond site, there's a spot for an 8 foot x 8 foot bog filter, which I'd likely make about 18" deep. As I said, the run would be about 20 feet, and the rise would be about five feet from the level of the surface of the pond to the level of the top of the bog filter.
I suppose the stream could be 2 - 3 feet wide, and done in steps, so there would be 3 or four mini waterfalls on the way down, and it could be lined with stones and planted with bog plants.
The stream and bog would be North of the pond. The deck, and deck steps, would be to the east. So on the west side of the pond, I'd have equipment. I'd put in a bottom drain, and have some sort of settling chamber (blue barrels?) right next to the pond. I'd put a submersible pump in the chamber to pump the water up to the bog filter.
But, just based on the local ground hydraulics, the pond is going to have to be raised up a little, maybe a foot. Otherwise, when it rained, water would get between the clay layers and the liner, and the liner would start to 'float.' That would be bad. A raised wood frame would prevent that. But, alas!
I did think of doing a single course of concrete block all around the edge of the pond. The liner could go over the top of the block, and I could put the stones on top of that. But then I imagined some of those blocks sinking into the clay, and shook with horror!
Then I thought I could maybe set the single course into a thin base of concrete. Then I thought I'd have to make it thick, and to do that, I'd have to do this other thing, and then something else, and pretty soon it would turn into some giant elaborate construction project which I'd be certain to muck up!
Help!
Thanks,
Bill