Decoration, Decorative Features, Gardening & Landscaping, How To, Stuart, Water Features

How to make a shishi-odoshi or ‘sōzu’: the Japanese bamboo water feature that goes ‘donk’

If you’ve seen a film that’s either culturally Japanese (Crouching Tiger, Hidden Dragon) or wishes it was (Kill Bill), you might have seen or heard one of these water features. A shishi-odoshi (called a sōzu when a water feature), or ‘deer scarer’, is the bamboo thing that goes donk, an occasional noise-maker previously designed to spook animals from your garden. Nowadays, they’re used to add an oriental flair to gardens across the world. And scare pigeons.

There are a couple of different sōzu styles, but they all follow a basic principle. Place for water to sit, place for water to run, big hollow for water to gather, hollow can pivot, thing the hollow hits when empty. This guide just follows one of those styles, but you can still use it as a template for your own sōzu creation.

Kit list

If you’ve ever wanted to make one, you’ll need:

  • A water reservoir, lid optional – the water needs to get back into it
    • An additional bucket if you don’t have a lid
  • A water feature pump and tubing (usually supplied with the pump). Go solar for true freedom
    • The power of the pump determines the possible height of the sōzu
  • 3 thick (large diameter) bamboo poles. Or one really long one to cut into pieces. They don’t all have to be the same diameter
    • One for the water pipe, one for the spout, and one to fill and go donk [pivot]
    • Alternatively, PVC pipe wrapped in bamboo canes will have a similar effect
  • A cap for the pivoting bamboo. Wood or plastic
    • Waterproof sealant for same. Bathroom sealant would do
  • 2 short posts, to mount the pivoting bamboo.
    • Wood preferable, not essential. Use bamboo for authenticity
  • A stainless or galvanised steel rod the length of (post diameter + bamboo diameter) for the pivot
    • Holes in your post will hold the rod in place. Just drill halfway through each one
  • Nuts or washers for a smooth pivot
  • A big flat stone/rock
  • Other decorative stones, bark, plants.

Tools

  • Power drill
  • Spade
  • Rubber mallet
  • Spanner or socket set
  • Bushman or other wood-cutting saw
    • A tenon saw will give you the cleanest cuts, but harder work

Step one – Prepare the area

The first step after deciding you want to build a sōzu is to mark out the area you want to place it. The reservoir placement will be fixed if you dig it in, but you also need room for the horizontal bamboo and the stone it hits as it falls. This area’s completely up to you, but decide on the area (and measure it) before committing to any supply purchases.

Broadly, your total area should be grander than the reservoir, but this isn’t a hard and fast rule. Just think about where the rock and pivot posts go. Then clear the area of any stuff that might be there already like plants, obvious rocks to give yourself a clear working environment.

Step two – Gather your materials

You can collect your supplies in stages, but like with any IKEA furniture, it’s best to have all your bits together before starting the build. If you’d rather stagger it, you can get the reservoir and pump at the same time, then the posts and bamboo/PVC and canes, then ironmongery at the end once your sizes and diameters are confirmed.

Make sure you’ve got somewhere to store these until complete – this writer recently completed a decking project and storage proved problematic for a staged build. None of the pieces should be over two metres unless you’re going for something grand, so space for a little pile should be sufficient.

Step three – Dig in the reservoir

You#’ve got a reservoir, you know how big it is and where it’s going to go. So now you just need to dig a hole for it. If your reservoir has a lid, dig a little deeper than the reservoir’s depth to make space for it.

If you’re an advanced hole digger you’ll dig straight down after marking out the precise area, going outside-in. If you’re more laissez-faire, just start digging in the zone you want your reservoir until you think the hole is big enough. Then, put your reservoir in it and see if it fits – if it doesn’t, dig a little more.

Once your reservoir sits level, you’re done digging for now. But don’t put the spade away just yet, unless you have an auger.

Step four – Prepare the spout

There are a few ways to do this, but the main consideration is this – where your water feature is going to pump water to to reach the pivoting piece. In the diagram above it runs up one piece of bamboo, flows through another then drops into the pivot, and the way to do so is as follows.

Cut a piece of bamboo down to size, the maximum height you want your spout to be plus around 20cm which will be driven into the ground. A second piece of bamboo will take the water over to the pivot, but this can all be played with once your upright is in place. Once you’ve got it to the height you want, cut or drill a hole in the side of the bamboo for your water pump tube to feed through – make the hole significantly bigger than the tube diameter.

The other end of the spout is up to you: you can run the tube straight out of the end or drop it out nearer the top. Try pencilling it out before committing to putting the spout in the ground – you’ll be annoyed if you decide to dig it out to cut it differently!

Step five – Prepare the pivot


In principle

This is the most crucial part of your sōzu, as this is the bit that goes donk. It constitutes two posts, the pivoting bamboo, and a rod through the middle. The angle of your pivot will determine how long it takes to fill, as well as the length, so think carefully about how you want the bamboo to sit at rest. The placement of the rod should be just above a node (bumpy bit) on your bamboo, so when you cut your bamboo down to size make sure a node is within the central third (or at the halfway point).

Your pivot bamboo should be longer on the open end than it is on the closed (the bit that hits the rock), otherwise it won’t tip when sufficiently filled. If once you put it all together it’s not tipping when you want it to, add a bit of weight to the inside of the bamboo (glue or screw in nuts and bolts) to reduce the amount of weight needed to tip.

Measure your bamboo, cut it with a 90-degree angle at the short end and a 45-degree angle at the long end, then drill a hole straight through it at around the halfway point, just above a ‘node’. Cap off the 90-degree end with something circular and glue (other fixings might split the wood), then use a bit of waterproof sealant for good measure. If water leaks out you’ll end up needing to refill the reservoir pretty often. Push your rod through the hole you’ve drilled, and check it can spin without force.

For the posts, dig them into the ground about as far apart as your pivot-bamboo is wide. Drill holes into them about halfway through, then assemble the pivoting part of your sōzu. Rod through bamboo, nut/washer on either side, rod into post, then rod into second post – you might need to do this before setting them into the ground, then rubber mallet them to keep them fixed. Give your pivot a wobble to make sure it still rotates smoothly.

Then put your big rock under the pivot-bamboo’s base.

Step six – Finalise the spout

Now you need to make sure water from your spout flows and falls into your pivot. Measure the distance, remove 10cm, then cut your final piece of bamboo to size. Once again, go for a 90-degree cut on one end and 45-degree on the end the water flows from. It just looks cooler that way.

Run your water tube out of your spout and through this last piece of bamboo. How you attach this flume to the spout is up to you, but be advised not to use permanent fixings until you’ve tested the flow.

The water from the flume has to fall into the pivot – if it doesn’t none of your sōzu will work! Turn on your water pump, then take note of where the water falls. Change the flume angle, shorten it, do whatever you have to to make sure the water reaches the pivot. Then fix the flume into place.

You can use rope, twine, glue, screws – whatever takes your fancy. Rope/twine will give you the best wiggle room if water starts missing the pivot. You can even use a second piece of bamboo, parallel to the spout, and attach it to both. Just be sure not to alter the placement you just worked out.

Step seven – Turn it on

Before we fill the reservoir with rocks and bits, we need to make sure it’s all flowing and refilling as we need it. Turn the pump on, then wait for your pivot-bamboo to fill. Depending on the size of the pump you’ve chosen, this should just take a few minutes but could be less or more. Once you’ve seen and heard a donk and you’re happy with the timings, you can work on the last decorative pieces.

Troubleshooting

The pivot takes too long to fill

Weigh down the open end with a few dense bits of metal, or wood if you’d like to preserve the natural look of it all. This reduces the amount of water that needs to pass the pivot point to tip it over.

Water doesn’t reach the pivot

Adjust the flume until it does. If you need to you can get some thinner diameter pipe to extend the length. You can also draw the water tube further along the flume, or push it back, to get a different result.

Water isn’t flowing

Make sure the water pump is free from all obstructions, and that the tube isn’t kinked within the bamboo. If you’ve chosen a solar water pump, makes sure it’s sunny or turn it off until it is – the internal batteries can run down if the feature is always on.

It moves, but doesn’t donk

It could be the shape of your rock is making awkward contact with the pivot-bamboo. Raise the rock on some stones, or bury it, until the corner of the pivot bamboo hits a good point on your rock – it’s the bamboo that makes the sound.

It doesn’t move

Your pivot might be too close to the posts, in which case you’ll need to hammer, wiggle and sand your posts to make sure they’re clear of the pivot. Also, check for water leaks to make sure your pivot is filling up correctly (you might need extra sealant where the pivot rod passes through the bamboo).

Step eight – Decorate

The decoration is up to you, but rocks, pond plants and the like will go well with the natural look of the bamboo. You’ll need to make sure the pump doesn’t/is unlikely to get blocked, which is where the reservoir lid or bucket comes into play. With a reservoir lid, you may need to cut a hole in it for the water to get back into it from the pivot, while with a bucket you’ll need to drill lots of holes into it so it stays under the water, protecting the pump, while allowing a free flow of water through it. Then put some rocks (or just one) on it to keep it in place.

Fill the rest of the area, then sit back and enjoy a garden of tranquility – with the occasional donk to punctuate the silence.

 

Bamboo header Photo by Franco Mariuzza on Unsplash
Seesaw Photo by Markus Winkler on Unsplash
Spade Photo by Andres Siimon on Unsplash
Garden bamboo Photo by Man Chung on Unsplash
Switching Photo by Danique Tersmette on Unsplash