Inverted Waterfall

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I first considered a flying piece, something along the lines of the car from Chitty Chitty Bang Bang Chitty Flying Car image, however I did not feel it was challenging enough. Yes during my research there were challenges in rigging and flying a car in the Atheneum due to size, weight and proportion, but by challenging I wanted to do something that is not really commonly done in theatre.

I started looking at the different elements, I came across the Chelsea flower show (random I know) and I noticed that it had a particularly interesting water feature. James Dyson has designed an uphill water feature which I found really interesting. So I have been looking into different methods to re-create this idea and how I would construct it on stage.

Project Outline

I intend to find out how I would go about rigging a waterfall in the Athenaeum Stage, not only do I want to find that out, but I want to try and see if it is possible to have it rigged in such a way that the water will flow upwards (against gravity) similar to what James Dyson did with his “Wrong Garden” at the Chelsea flower show.

Firstly I’m going to look at what sorts of problems I may face when rigging a waterfall on stage and come up with solutions. Then I shall look at materials, equipment etc. I may need and the costings for these. Knowing all this will allow me to determine whether or not it will be probable to get the water to flow upwards.

Ideas for Inverted Waterfall

A few methods for making water travel uphill

I have three ideas to create an inverted waterfall. The first, building a pool and using James Dysons method by using a pump on ground level, pumping air upwards and the bubbles would create the illusion of water flowing upwards. The second is using a conveyer belt. The main principal would be speeding up the motor on the conveyer belt so the upwards travel of the belt will travel faster than the downward flow of water. The third is creating heavily aerated water under high pressure which would run upwards inside a perspex former to provide the shape and movement of water and a mirror at the top to give the illusion of a pool. Definetly for the first and second idea I am going to have to build a pool of some kind.

Waterfall- Problems and Solutions


The main addition is that there will be a constant sound of water as it falls into the pool…or will there be as I hope to construct a waterfall where the water travels in the opposite direction. Nevertheless there will be some noise from whatever the flow of direction the water will be. There are many ways to over come the noise, whether it would giving the actors radio microphones, living with the sound as part of the sound design or placing the water as far upstage as possible. One way to lessen the sound is to have the water hit a steeply slopped surface that runs down into the pool at the bottom rather than have the water fall directly into the pool. Making the pool shallow or having something soft in the pool for the water to fall would not work as I found out from research. In addition to the noise there is the splatter problem. All surfaces anywhere near the waterfall must be sealed or be made of a material that will quickly and easily air dry on its own without soaking the surface underneath.


Another thing to consider is to reduce to risk of mildew, mould, fungus, bacteria etc. Stages are not the most pristine and cleanliness of places, dust, dirt and a myriad of other surprising things will find there way into the water. This is why the water should be treated with a mild, non chlorine pool or spa treatment to prevent any possibility of bacteria etc. The reason for the non chlorine treatment is twofold. First, the chlorine smell can be objectionable and is easily detected by the audience. Second, any costume that comes into contact with the water will slowly be bleached out. The water should be changed at least once a week, depending on how much contamination it gets from dust, dirt etc.

Pump- What kind of pump should be used?

The easiest to acquire are the submersible sump pumps. These are usually fractional horse power pumps ranging from 1/4 to 1/2 horse and from 1400 to 4200 gallons per hour. Which one I choose obviously depends on the budget and the design perimeters of the situation. Generally it is a good idea to use the largest pump that my budget would allow without overkill. It is easy to restrict the flow with a ball or gate valve, it is impossible to get a pump to push more water than its rating. It is often more economical to use two smaller pumps rather than one larger one. As this will give me a bit of a safety margin. If one pump fails, then I would still have water, not as much, but some. I will also need to consider if there will be any kind of "natural" water effects, e.g. grass and other things run down to and in the water. I will need to be very careful what and how I would do this as there is the chance of a wicking effect pulling the water up and away. This can lead to a soaking of areas around the stream or pool and, in effect, a slow leak.


Obviously it needs to be taken into account that there may be leaks. A way to help with the visibility is to build the effect (waterfall) with access to as much of the stream or pool bed as possible, so that leaks may be spotted and repaired as easily as possible, without having to tear up half the set to find and fix them. As the needs and design of water effects are so varied, I found out that this discussion has intentionally been very general, with little attention to specific details.


Final effect for The Atheneum Stage

Theoretically I have been approached by a designer asking me how I would, from a TSM point of view, rig and install a waterfall. They have also asked for it to be inverted so the water travels upwards against gravity. First things first the positioning of the waterfall is very important, it would need to be somewhere practical for the water supply and drainage. To keep things simple I would prefer to have the waterfall installed DS, closer to the SL side. This will allow me to have easy access to the Ath kitchen and the pit.

Building a pool

A pool is simply a reservoir that holds water. This is not complicated to make, but introduces a few concerns not usually present in most theatrical problems. The first step is to construct a base for the pool. This will however cause a three-dimensional scenery problem, since I want my waterfall to look as natural as possible, which has the rather inconvenient property of not being in regular, easy-to-build geometric shapes. (I like making things hard for myself, as a simple cubic basin would have made things a lot easier). So basically this calls for building a frame for the pool that is irregularly shaped.

An important issue in building the frame is the weight of the water it will need to support. One cubic foot of water contains 7.48 gallons of water. One gallon of water weighs 8.34 pounds, so one cubic foot of water weighs 62.38 lbs. For a pool of any reasonable size, this quickly adds up; for large volumes of water, careful structural analysis will be important to ensure that the frame will be able to hold the weight. In addition the weight of scenery such as rocks or tress and the framework to hold and contain the water must be considered. Also there may be a live load of the actors which can add up very quickly, depending on the action or lack of. A pair of performers weighing 120 pounds each can easily add up to one ton of impact loading if they are cavorting or dancing. If however I decide to put the pool bottom directly on the main stage floor, there is rarely a problem. Most stage floors are rated at 150 pounds per square foot or higher. Although this may not be the case for the Athenaeum, I have yet to find out the load weight the Ath stage can take. But if the pool is built on a raised platform the scenic unit has to be built to take the weight and all the live action. One way to minimise the amount of water used and the amount of weight that must be supported is to make to pool less deep; this is a very reasonable option since the actual depth of the pool will not always be obvious to the audience.

I was thinking that the frame for the pool should be made from plywood, something sustainable like 18mm. The ply will need to be covered with a pond liner so that it can be filled with water. Soft liners must be supported on all sides and surfaces, just like above ground pool level. Otherwise the weight of the water will put the liner away or possibly rip it were it is fastened along the edge.

Steps to Install a Waterfall

  • Built out of Perspex
  • The waterfall will be built in a wedge shape, so 3 meters high, 4 meters in lenght and 2 meters wide. This will give me a 45 degree angle on the slope for the waterfall. Refer to sketch below (I'm having problems uploading).
  • Under the sloping section there will be a seperate area in which the piping can get installed.
  • Install pump and tubing (take into consideration both the vertical and horizontal distance that the pump will be pushing water). Four pumps will be installed, two at the front of the waterfall to push the water upwards onto the slope and tow at the back so the water is pumped through the piping and reaches the other two pumps at the front.
  • Secure the plastic tubing to the pump outlet with a hose clamp and route the remaining tubing to the waterfall.