Accenting a pond with a waterfall adds a new dimension to a backyard or garden. Incorporating a waterfall can benefit the pond by helping circulate the water, making it more habitable for fish and other aquatic animals---especially if you choose to use a pump with a built-in filter. Basic tools and supplies from the hardware store can help you create a waterfall for a pond in a few days.
Select the site on the edge of your pond where you want the waterfall to go. It should be flat and easily accessible, and visible from the main area where you view the pond.
Dig a small trench from the edge of the pond to where you want the pump to go. The trench should be below the water level of the pond.
Thread the pump hose through the poly piping, then lay the poly piping in the trench, with the end of the pump hose sticking out into the water of the pond. Fill in the trench with soil, compacting it down with your shoes. Attach the end of the pump hose to the pump, and the end of the waterfall hose as well.
Lay the biggest stones first to form the base of the waterfall, positioning the waterfall hose so that it is in the centre of the base. The stones should be large enough so that they sit sturdily, and won't need to be cemented.
Continue laying stones to build the waterfall, threading the waterfall hose up through the centre as you go. Avoid just piling the stones on top of each other, as this can look like a tower. Stack them to create a vaguely pyramidal shape, with some ledges in the front where the water can pool before flowing down farther. Lay the stones laterally, rather than vertically.
Test the flow of water with the garden hose, positioning it so that the water comes from the same place as the waterfall hose. Rearrange any rocks that are obstructing the flow.
Cement any rocks in place that seem unsteady, especially those closer to the top. All the stones shouldn't need cementing. Let the cement cure for a couple of days.
Turn the pump on. Water should be drawn from the pond, through the hidden pipe, up out of the waterfall and back into the pond. If this doesn't happen, make sure that the pump pipe's end is fully submerged in the pond water, and it is properly attached to the pump Give the flow a few minutes before rechecking the connections. Check if anything is blocking the end of the pipe, such as pond weed. If necessary, pull the pond pipe out of the poly piping to check for blockages or leaks.
To help control the flow of water, place a stone in front of the pipe opening so the water flows around the sides. If there are already fish in the pond, remove them before beginning work.