Lydia Nielson has herself some mad water skills. She's who turned us on to Viktor Shauberger. Here she's showing her plan for her water system at her home. It ends up in a 3' deep pool! With fish! She says a great heron harvested some of her fish for her. How cool is that? She reports that she wishes she'd made the reedbed larger. I'm hearing that from many of the greywater advocates. It seems as though your reedbed can never be too large. To my way of thinking, it seems reasonable to overdesign by a factor of two (the space required might be a consideration) because I bet the reeds will fill out to 50%, 75%, or 100% of the space depending on the water's availability. I guess I value water that's full of plants more than open pond water.
All man-made ponds will require some maintenance. We've had 4 inches of rain recently, yet all it took was one look at the pond at APC and Lydia knew something wasn't right with it. I'd been to it during the rain, so I was able to report to the group that the water sluiced right past the channel that led to the pond. We re-dug the channel, re-set some pond liner, attempted to design for getting the water all the way into the pond, pulled a bunch of plants from the pond, and planted new starts all around. We rebuilt the path that crossed the channel (you know how pedestrian love to cut across corners!) and we re-set the rocks to make it look a little more natural.
One really fortuitous aspect of the pond's placement is a large shade tree to protect it somewhat from the sun. Not that on a very cold day in March there was much sun to worry about, but Lydia explained how heat is the enemy of water. Hot soil will reject the rain, while cool soil welcomes it for nice deep infiltration (for example). Rivers with overgrown banks have cleaner water, and don't carry a silt load (for another example).
Today it rained, so Nick and I went out to see how the classes' work was holding up. He noticed right away that we still had standing water in the diversion channel (I suppose we could have played with an A frame when we reshaped the channel), but he also noticed that water was definitely making it to the pond. "The water is making mushroom shapes!" he said, noticing the turbulent flow as the silty water (we didn't wash the stones) from the channel entered the pond. "Is the dirt going to be a problem?" he wanted to know. I'd seen how much plant matter got pulled out of this wetlands, and so I told him I was pretty sure the plants would enjoy the dirt. I also noticed that even with the light rain we were getting, the pond was full, and water was making its way out the far end.
All in all, I think we did a pretty good job on pond maintenance, and I really like that I got to share the space with my son.