Introduction: Raised Timber Pond With Waterfall and Bench

About: I have been hooked on making stuff, and sometimes breaking stuff since I was old enough to unlock my Dad's shed. I've been playing with tools ever since and am currently studying Product Design at University. …

In this Instructable I will take you through how I designed and built a small raised pond with a capacity of roughly 300 litres, using 47x47mm sawn kiln-dried timber and 140mm wide decking boards. My design measures 1800 x 600mm on the pond side (including waterfall tower) and 1400 x 450mm on the bench side (including waterfall tower), with the pond and seat at a height of 445mm, and the waterfall tower at a height of 865mm.

I also implemented accent lighting, a stainless steel waterfall and a bench with a hinged seat, all of which are optional as this method of construction would be flexible, allowing you to design your pond more to your requirements. This particular design was just my favourite for my budget of around £300 (about $470) including all fittings (pond liner, pump/filter, steel waterfall and lights etc.).

This Instructable assumes that you have experience in drawing up and planning out projects like this yourself, as this is very much a 'this is how I did it' kind of Instructable, and there are loads of different ways for how you could design and build your own version. If there is demand for more details on my exact design, I could upload my cutting list and working drawings etc.

If this Instructable helps you, or you have enjoyed reading it, I would really appreciate it if you could click 'vote' and 'favourite' at the top right-hand corner of the page, thank you very much!

Step 1: What You Will Need:

For designing and drawing up all the plans, I used AutoCAD 2013 under a student licence, which is free to download and use and I found the easiest way to accurately plan the lengths of each component.


  • Workbench
  • Mitre saw (preferably with a blade larger than 210mm)
  • Battery-powered drill/screwdriver
  • Pillar drill/electric drill
  • Handsaw
  • Hand plane
  • Router (dependent on your design - not essential)
  • Set square, tape measure, pencil etc
  • Kraft knife

Materials: (amount of each dependent on your design)


  • 4.2x65mm decking screws
  • 3.5x30mm exterior-grade wood screws
  • Pond pump/filter (I used a submerged 2000L/H all-in-one pump, filter and steriliser for about £50 from eBay)
  • Stainless steel waterfall (optional depending on your design, available on eBay in many different sizes, mine was 400mm wide and cost around £50)
  • 25mm corrugated plastic pipe (if using an external filter or waterfall)
  • Decking lights (optional)


All timber and screws were bought from Wickes, Angle brackets were purchased in packs of 10 from Screwfix, Pond fittings and decking lights were purchased from various sellers on eBay.

Step 2: Planning and Design

When looking for a location to build your raised pond, it is vital that the ground is completely sturdy and as level as possible, as you don't want the level of water in the pond being dramatically deeper on one end of the pond than the other. This is especially important if you intend on including a waterfall in your design, as if the waterfall is not level then the water will not flow in an even 'sheet' as it is supposed to.The waterfall must be installed completely level to give the proper effect.

After coming up with a final idea for the project, I quickly modelled the design in AutoCAD 2013 to decide on the appropriate proportions and dimensions, and begun to tackle how I was going to make it. I decided to construct a frame out of 47x47mm timber, then screw decking boards to the outside for both aesthetics and to hold the liner in shape. Please find attached the .dwg file of my drawings, to get all the sizes of components off, use the command 'MEASUREGEOM' then select 'Distance' in AutoCAD.

This made the pond itself very strong and easily capable of containing the <300 litres of water. However, if I were to make the pond much larger in terms of size and capacity, I would have screwed 18mm thick marine plywood to the inside of the pond frame but still use the decking as an external cladding; the plywood to stop the pond liner being contorted into weird shapes and pressing against the inside of the decking, to make the design significantly stronger.

Step 3: Cutting Timber to Size and Finishing

Before you buy your timber, do the following to prevent you wasting material while potentially saving a fair bit of money for barely 15 minutes extra planning:

  1. To reduce waste materials, and therefore wasted money as much as possible; prepare a full list of all the lengths of 47x47mm and decking boards that you need to cut.
  2. Now, work out the best combination of pieces to cut from each length of wood to minimise waste, by taking the length of wood you have to start with (the decking I was using was 3600mm long, the 47x47mm was 3000mm long) then just use a calculator to work down your cutting list and try to figure out the best combination of pieces you can get from each length of timber that leaves you with the least non-usable waste, for example I needed two lengths of decking at 1800mm, so I simply cut one of the decking boards in half.
  3. Tick pieces that you have arranged onto lengths off your list to help ensure you don't buy and cut more than you need.
  4. You should now have arranged each piece of wood you need to cut onto a certain length of timber, leaving you with the number of pieces of timber you need to buy.

Marking and cutting:

  1. Use a tape measure to accurately mark the length of the piece you intend to cut with a sharp pencil. Use the set square to mark the length all the way across the length of timber. I found it useful to mark which part is which by simply writing its length in mm on the back of it in pencil.
  2. Use your mitre saw to cut the lengths of timber to size, being careful to ensure that any long and heavy ends of the wood will not fall to the floor after being cut, as this could be dangerous.
  3. Use some medium grit sand paper to clean up all cut ends of the timber, to both remove any burr/splinters and get a neater finish.

Side note: The mitre saw I was using has a 210mm blade, which only cut about 3/4 of the way through the 140mm decking boards with each cut; to tackle this I simply made the first cut on one side of the decking board, then flipped the board over, lined up the blade with the existing cut and cut again. This was no real issue, but I would recommend using a larger blade which can cut all the way through the 140mm wide boards in a single cut.


  1. Because the frame will be in direct contact with the pond liner, the liner will be forced to take on the shape of the frame, meaning leaving sharp edges and corners on any areas of the frame that will be in direct contact with the liner is not a good idea. To make the changes in shape of the inside of the frame more gradual, I used a hand plane to round any edges of the 47x47mm timber frame, then ensured that all splinters were removed and everything was smooth using a sanding block and medium sandpaper.
  2. If you are using an external pump or waterfall and are using a similar design to mine, with a section of the pond higher than the pond itself (the waterfall in my case), you will want to drill a hole that is about 5 mm larger in diameter than the diameter of pipe that you want to run through the hole. I used a rounded file to file a further groove out of this hole to allow the wire to the filter/pump through.
  3. If you are installing decking lights, drill the holes in the relevant parts now using an electric drill or pillar drill, drilling the size hole that the manufacturer recommends. You may want to drill a hole in a scrap piece of decking now just to make sure your lights fit in that size of hole fairly tightly.
  4. In my project, I decided it best to have the waterfall mid-way up the 'tower', to try and minimise the effect of wind on the waterfall (at a height of about 300mm above the water level). To do this, I marked a slot out of one of the decking boards using a tape measure, set square and ruler. I then cut it out using a router and hand saw, sanding the cut edge to remove any burr and splinters.

Now apply your external wood finish to all of your pieces of wood making sure to follow the manufacturer's instructions closely and accurately to ensure the best finish. Once your final coat is dry, we're ready to start building!

Step 4: Building the Frame

To build the frame of the pond I simply used the cut and treated lengths of the 47x47mm timber, joined together with zinc-plated angle brackets.

  1. Hold the two lengths of 47x47mm timber in place where they are to be joined. Use a set square to ensure that the joint is square.
  2. Place and hold an angle bracket into place, making contact with both pieces of timber, and proceed to break the grain of the timber where the 3.5x30mm woodscrews are going to be screwed into place in the first bit of timber, using a bradawl or screw etc.
  3. Use a hand drill with the appropriate screwdriver attachment to drive the screws through the mounting holes in one of the brackets to mount the bracket in place on one of the pieces of timber.
  4. Rest the other piece of timber to be joined into place, and screw the piece of timber into place on the bracket. You may want to repeat on the other side of the joint if you are forming a 'T' joint.

It probably took me about 6-8 hours in total to construct my frame. When your frame is done, it's time to start screwing the decking onto the frame!

Step 5: Attaching the Decking

I found attaching the decking to my frame to be a fairly quick process, taking about 3-4 hours.

  1. Take the appropriate length of decking and hold it in position against the outside of the frame.
  2. Attach the board to the frame using 60mm decking screws and a hand drill with the right screwdriver attachment. I used two screws on each joint where the board was being attached to the frame on each of the frames 'struts'. My favourite way of attaching them was to loosely screw the board onto the frame at one end with one screw, then go to the other end and put in another screw, then simply work your way back along the board putting in screws where desired.
  3. Continue this process until all of your decking is in place, apart from the pieces that are intended to be used to clamp the pond liner in place (the 'capping'). I also left the top of my waterfall uncovered until the very end to allow easy access and modification.

IF YOU ARE USING LIGHTS THAT WILL BE UNREACHABLE WHEN THE LINER IS IN PLACE AND FULL, FIT THEM NOW. Also you will want to ensure that all of these lights are working now, as there's not really any going back and changing them once the pond is full.

Step 6: Fitting the Pond Liner, Filling Up

This is the last chance to make sure there are no sharp objects on both the inside of the pond itself, and on the floor under where the pond itself will be, which could potentially puncture the pond liner. Because I had situated my pond on a slightly bumpy patio, I put squares of old carpet to cover the exposed patio to further help prevent any stones puncturing the liner (see first picture).

  1. Firstly, place the underlay loosely over the top of your pond (with a good deal of excess on all sides) and press it down into the pond, trying to smooth out as many creases as possible and get the underlay to match the shape of the pond as well as possible. Make sure there is still a fair amount (at least 40cm) excess of underlay sticking over the top of your pond.
  2. Do the same with the pond liner, placing it on top of the underlay, really trying to get the liner to match the shape of the pond as closely and neatly as possible. This can take quite a while to get it all looking neat, but a poorly-laid liner really can take away from the aesthetic of the pond a great deal.
  3. Slowly begin to fill up the pond from a hosepipe attached to a tap, pulling the liner into the neatest position possible as the pond begins to fill.
  4. Carry on guiding the shape of the liner and where the folds are forming right up until the pond is full.
  5. Its recommended that you fold the excess liner and underlay over the edges of the pond, temporarily keeping them down with bricks etc. in order to let the pond sit for about 24 hours, to ensure the liner has settled into its final position before putting the capping on.

There are many excellent guides on calculating how much liner to use for your pond, and how to lay it, which I would strongly suggest you look into particularly if you have never built a pond of any kind before.

Step 7: Installing Pump/ Filter and Waterfall

Following the manufacturer's instructions, install your pump and filter as required.

If you are installing a waterfall, connect the hose from the pump/ filter to the correct inlet on your waterfall and secure the hose in place using a hose clip.

Because the patio that I built my pond on was a bit uneven, I had to angle the board on which the waterfall was mounted a little bit in order to get the water to fall evenly. To do this I simply used a spirit level to mark where it is level, then screwed an off-cut of decking underneath the waterfall to hold it in place.

Now the waterfall is up and running, now is a good time to make sure that the spill from the waterfall will not be landing on the capping when it is in place, as this would lead to excessive splashing.

Step 8: Attaching the Seat, Capping, and Finishing Touches

To make the seat, I simply screwed 3 lengths of decking to 3 perpendicular lengths of 47x47mm timber underneath, then attached it to the back of the frame using the tee hinges. Make sure that the seat can freely hinge up and down, and that as much of the seat as possible is in contact with the frame beneath it to minimise strain on the hinges and seat when someone is sitting on it.

I attached the rest of the cladding to the waterfall tower, now that the waterfall has been properly adjusted.

Now that the seat and the rest of the decking is in place, we are ready to attach the capping, and trim the excess liner/ underlay.

  1. I now remeasured the dimensions of where the capping will sit on the frame, and cut one end from each of the long sections, and both ends of the shorter section to 45 degrees, to allow the capping to fit neatly together.
  2. When your capping is cut and treated, fold the pond liner and underlay neat over the edges of the pond, place the capping into place, ensuring that the liner is pulled tightly under the capping and that the liner looks as neat as possible.
  3. Secure the capping in place with decking screws, and the liner should now be firmly clamped in place.
  4. Using either a kraft knife or good scissors, trim off as much the excess liner and underlay on the outside of the pond as possible, to make the pond look as neat as possible.

To provide power to the pump and lights, I installed an external double socket just under the seat, hanging it off the inside of the frame using cup hooks. Make sure that your pump/ filter etc. is plugged into a circuit breaker of some kind, for example I plugged the external power supply cable into an RCD on a socket indoors.The hinged seat hides the power supply well, yet allows for very easy access.

To make the seat more comfortable to sit on, we simply put temporary outdoor cushions on the seat whenever it is in use.

To add more interest to the pond, I bought a potted water-lily and a 'barred horsetail' plant, and placed plant pots on top of the waterfall tower and around the rear edge of the pond.

I let the filter run for a week before putting any fish in, just to let the chlorine in the tap water evaporate out and to make sure there were no issues with the pond.

At the time of writing, the pond has been up and running with fish in it for just over a month.

Thanks for reading my first Instructable! Please leave some feedback in the comments and let me know if you build something similar to this yourself, I'd love to see it! Please don't hesitate to contact me with any questions if I've been unclear at any point and as I said at the beginning, if there is demand for my cutting list and detailed drawings etc. I will work on uploading these as soon as I can!

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