To make a rock waterfall, whether in an existing pond, or from scratch with a pond or pondless, careful preparation is important before the actual waterfall is built.
A waterfall kit can be purchased containing the submersible pump, tubing, liner, and waterfall head, along with fittings, pump housing and expandable foam to caulk between the rocks, or these different parts can be purchased separately. Placement of the pond, the spillway, and the head of the waterfall as well as its size in terms of the head height, the length of the spillway and the distance from the pond to sources of water and power must be considered. The pond should be close enough to the power source so that the pump can be plugged into it. The waterfall should be behind the pond so that it flows toward the viewer into the pond. The head of the waterfall needs to be higher than the surface of the pond. If there is a natural slope in the ground because it is located on a hillside, a waterfall box can be buried up to its brim at the head of the waterfall. If the ground is more level, a berm, or artificial slope, can be built up from the dirt that is dug up from the pond.
Rocks, Rocks, and More Rocks
The most important part of the rock waterfall, of course, is the rocks. About around 20 rocks of different sizes and shapes could be collected or purchased, or more depending on the size of the waterfall and pond. Keep in mind the design of the waterfall when selecting rocks. Large flat rocks with straight, sharp, squared off edges will highlight the waterfall over which the water will fall and cascade down into the pond or rock pit. Boulders and smaller rocks serve to cover the spillway, hide the waterfall head, hold down the lining and make a border around the waterfall system to contain the water within it. If the waterfall is pondless, even smaller rocks will be filling and covering the reservoir.
The Pond or Reservoir
If a pond does not already exist, it needs to be dug. If the liner is a rigid box or tub, the hole should be dug the same size and shape as the liner so that the liner can fit inside it buried to the rim. The position of the liner should be adjusted in the hole so that its upper edge is level and is even with the ground around the hole. If lined with a sheet-like liner and an underlay, this can be laid in the pond or reservoir hole and smoothed against the bottom and sides. Trim the liner so that there is a generous amount of the liner material extending past the upper edge of the hole. Secure the edges with boulders and rocks on top of the liner margins. Secure the pump, within any pump housing, to the bottom of the pond. Attach the tubing to the outflow and thread the tubing and the power cord through holes in the housing and out of the pond.
The Head of the Waterfall and the Spillway
Lay the tubing alongside the outline of the waterfall system to the head of the waterfall. Attach the end of the tubing to the waterfall box or thread it through the tubing housing so that the water flow is directed toward the front of the waterfall. Dirt and rocks can be used to surround and cover this housing assembly and hide it in an aesthetic manner. The spillway liner can then be used to line the spillway and rocks placed on the liner in such a way that the water will cascade over and splash onto successive overlapping large flat rocks. Boulders are placed on both sides of the spillway in such a way that the water flows down between them to the rock bed or pond and secures the margins of the spillway liner. If the waterfall is to be pondless, fill the pit with gravel and top with a layer of decorative rocks.
Fill the pond and the waterfall box with water. Plug in the pump and turn the waterfall on. Fix it until just right. Add plants if desired to the rock waterfall for a beautiful waterscape.