How to Build a Waterfall

Pond Filter Waterfall

Are you wondering how to build a waterfall? These instructions should help.

Building a waterfall poses some unique design challenges. The number one concern is waterproofing.

The typical waterfall starts with a natural incline or mound of subsoil excavated for a garden pond perhaps with a garden retaining wall or other filler. The face of the waterfall must be sealed to keep water from escaping and to prevent dirt from washing into the lower pond.

Ready-made waterfalls are available from various pump and fountain manufacturers. These are easy to install, but don’t look very realistic and your shapes and options are limited.





Contrast this to the flexibility that you will have if you build your waterfall using a flexible pond liner for the channel to flow over real rocks. Rocks and plants can be used to hide the edges of the waterfall channel. Check out how to build a backyard waterfall using a pond free backyard waterfall package.

You will need a submersible or external pond pump to move the water from the bottom pond back to the top of the waterfall where gravity will do its job to send it back on its way over the pond waterfalls. Select a pump that is large enough for the height of your waterfall. You will need a large pipe flowing from your pump to make sure you get a large flow of water. Install a gate valve so that you can control the flow of water to your waterfalls.

Be sure that the bottom pond can hold all of the water in your system when the waterfall is turned off.

Structure of a Backyard Waterfall


Steps in How to build a waterfall

1. Mark the layout using a garden hose or rope to mark the outline of the holding pond and waterfalls. Plan several curves and decide where the waterfall will be. Once you have decided, mark it with spray paint.

2. Place the waterfall box in a hole at the top of the waterfalls. Install the water-supply pipe connection and the pipe to the back of the box. Make sure the box is perfectly level. Once it is positioned, fill around it with soil to make sure it stays in place.





3. Dig out the holding pond. This may be your koi fish pond, or a secondary pond that you create specifically for the falls to flow into. As you dig, pile up the dirt that you dig out to one side. This can begin to form the slope of the falls. Shape the slope to give it a step-like effect.

4. Install the skimmer box at the pond’s edge. Set the box on the base of crushed rock. Be sure that the box is perfectly level. Set the pump into the skimmer box. Install pond liner around the face of the box. Install a check valve to the pump’s discharge side.

5. Build up the borders of the stream bed and pond with rocks to prevent water from washing over.

6. Run the supply line (2 inch diameter) between the pond and the pump skimmer box. The supply line can be buried in the stream bed or run up the side of the garden. Bury the pipe at least 6 inches deep to protect it from damage.

7. Next, install a pond liner. Place padding underneath where the pond liner will be. Carpet padding or a layer of sand is good for this. Next install an EPDM pond liner in the pond and up the side of the waterfall steps. Leave the liner untrimmed until the pond is filled with water.

8. Hide the waterfall box by placing rocks around it.

9. Place large rocks into place on the face of the waterfall. This part of the project will probably require some help lifting the heavy rocks. Position the rocks carefully so as to not damage or displace the liner. Secure the rocks with mortar as needed. Leave a lip where the water will flow into the pond.

10. Add finishing touches by scattering some gravel between the large rocks. Hose off the rocks to remove any dirt. Pump the dirty water out of the pond, and then refill the pond. Once the pond is filled, fold the excess liner and tuck it beneath rocks if possible.

11. Finally, add plants, shrubs, and flowers.

How to build a waterfall as part of your biological filter

You can install a waterfall as part of your biological filter system. When we built our external biological filter, we had the water from the filter spill into a secondary pond and then into a lower pond where the fish were. We planted plants in the secondary pond, which helped filter the water.

Building Waterfall with Biological Filter


If you have suggestions for improvements to these ideas on how to build a waterfall, please be sure to let me know.

A waterfall is a great addition to your pond. It adds beauty, but more importantly it adds aeration and contributes to a healthy koi pond.

There are a number of disappearing waterfall kits that are available to help make this even easier for you. They include everything you need on how to build a waterfall.

If you have questions about how to build a waterfall, please contact me. I am here to help.






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