Some time last year I was doing something by the pond waterfall and thought to myself, “Huh. Wasn’t there a shutoff valve on the piping for the waterfall somewhere around here?” But I couldn’t find it. And then I promptly forgot about it.
We have a fairly big pond, with a pump that sends pond water through pipes up a small rise and over a big rock to run down a short channel layered in pebbles and rock ledges and back into the pond. (It’s called a “pond waterfall” but that term can only be applied accurately if it’s applied very loosely.) But it looks nice and it sounds nice and the birds have baths in the channel.
A couple of years ago a big tree fell on the big rock. It didn’t appear to damage anything, but we realized that summer that the rock’s angle had changed very subtly, so some adjustments to the piping were necessary to keep the water going in the right direction. But even with those adjustments there seemed to be some leakage, so this year I decided to see what I could do to fix the problem short of engaging a backhoe. So once the water level had dropped till the pond contents were mostly mud and the pump was turned off it was time to start work.
- dig out all the small (20- to 30-pound) rocks lining the channel and remove the earth and weeds now engulfing them
- rehabiliate the pebbly edging on the outside of the channel in order to slow the assault of the engulfing weeds
- adjust the channel lining where possible in relation to the earth in order to ensure that water flows in the right direction and can’t get over the edge (this is challenging as one of the pipes goes over the liner edge)
- remove the crud from the channel so there’s more nice rock and pebbles and less slime and gunk
So that’s what I’ve been doing for the past couple of weeks. I’ve dug out a section of the smaller rocks and cleaned up a top section of liner. And then I started the pebble rehab on the outside.
My god, what a job. It consists of digging up pebbles—yes, digging them up, they’re buried under years of forest debris that in our climate quickly turns to dirt—and sorting them into a clean pile, then more or less levelling the dirt (filling in the pebble holes, anyway), laying new landscaping cloth and replacing the pebbles on top. It takes an hour or better crouched bent over on a gardening stool—oh my aching back—to do an area about two square feet. The photo gives an idea of the process.
At any rate, today I remembered that the missing shutoff valve was somewhere near where I was working, so I had a go at raking back the soil and pebbles in that area. And there it was—at least four inches down. Since I’d last seen it about four years ago, this means that the rate of accumulation of detritus is at least an inch a year. This does not bode well for the newly cleaned pebbles…