Outdoor Space Design Guide

How to Install a Pondless Waterfall

If you'd love a water feature but space is tight in your landscape, try a pondless waterfall.

More from Gardening by the Yard
Filed under: Waterfalls, How To, Water Features, Stone, Materials and Supplies

A water feature, with its calming, natural sound, can add new interest to your landscape and attract a variety of critters and birds. If space is too limited for a full-fledged pond, though, Mark Harp suggests another idea: a pondless waterfall. A pondless waterfall takes up much less space than a regular pond or pool because the "pond" is actually underground. This water feature's size can vary from triple-tiered falls to a single-step fall that can be installed in a weekend. Here's an overview of how it's done.

(Note: Mechanical parts for a pondless waterfall are available in kit form or you can buy them a la carte at a hardware store. Also keep in mind that most water features, other than birdbaths, do require electricity. If you don't have a readily available source of electricity at your pond site, Paul James suggests you hire a professional to install one.)

Figure B

First Steps

Choose a spot for your waterfall that's highly visible, a spot where you can enjoy the feature from inside and outside your home. You'll need about a 5' x 5' area, and you'll be excavating about 18 inches deep. Remove any shrubs or trees that may be in the way.

After preparing the hole, situate the housing unit, or snorkel, in the dug-out space. Outline the area where the housing will sit and excavate a few inches deeper. The snorkel must be below grade so the water can easily be drawn into the pump.

Figure C

With the pump housing out of the excavated hole, lay the first of two liners in. The first liner is designed to prevent any natural gases from entering the water flow. A second liner, the waterproof membrane, is then placed on top. When installing the liners, make sure you have plenty of overlap around the edges; don't worry about creases.

Next, place the pump unit in the lined hole and follow the manufacturer's instructions on how to properly assemble and attach the hose.

Figure D

Rocks, Rocks and More Rocks

Now it's time to fill the pond with rocks. You can collect rock from around your landscape or purchase inexpensive river rock. Looks don't matter at this stage.

Bigger rocks fill the hole first, followed by smaller rocks to fill in gaps and provide sufficient drainage. Once the hole is filled, quarry rocks are used to construct the face of the waterfall.

With the lower pond portion complete, it's time to level the upper area and assemble the waterfall unit, which will sit just at the top of the falls. Use a metal clamp to secure the hose to the unit, then position the unit at the edge of the falls. Secure the unit with soil until it's almost flush with the ground.

Figure G

Finishing Up

With the upper and lower plumbing in place, it's time to cut away excess liner around the pond area and attach the liner to the lip of the waterfall unit, following manufacturer's instructions.

Using a thick layer of waterproof foam sealer, Mark attaches a thin piece of slate at the mouth of the waterfall unit. He uses a few more quarry rocks to conceal the box completely. Below, at pond level, he completely covers the rock-filled hole with coarse gravel and uses a water hose to begin to saturate the area with water.

Once the pond area is saturated, plug in the pump and your waterfall should appear. Don't worry: the water, brown at first, will eventually run clear.