depend on how high is the waterfall, you will need to know the size of the pump needed.

Always do a sketch before building anything even though it may be simple.

You’ll need a waterproof liner or some sort of waterproofing as well. . .

go to your local garden center. See what they have available. Pick up a book on fountains. Survey the site. Collect the necessary equipment to do the job.
good luck

be sure pump is adequate to deliver water with how ever many feet of waterfall you have to overcome. (Head pressure)
Try to have a source of water close to top off the reservoir with losses like evaporation.

If your having goldfish in the pool of water then be careful of coloring or chemicals you put in the water, Try to put suction more to side then on bottom of tank so it does not get plugged up with debris.

volcanic rocks will be great for that!. . Especially, when you are aiming to get that “nature feel”. . Plants grow best in that kind of rock. . . Hmm. . .

Also, it is best to use the right “size” of pump. .

It depends on how big the waterfall will be. . .

Adding a pond with a waterfall, or just a waterfall in your mother’s yard will give her years of peaceful enjoyment. Pump sizing has a lot to do with how high the waterfall will be. Rock placement will have a lot to do with the sound that it generates, so try to experiment with that before you fix any of the stones permanently. It’s amazing how subtle changes make a big difference.

There is a link for a free e-book on our website that has some great information. Check it out at-

Http://www.Gardening-at-the-crossroads.com/water-gardening.html

depending on the size you will need flat rocks a liner for under the area that the waterfall is going to be and a pond for the water to fall into.

If you already have a pond then pick one end to build your fall on. I found it easier to stand in the pond when I built my waterfall. By standing in front of the area you want the fall you can adjust the rocks according to the angel you will need to make the water flow downward. Get a pump to pump the water up to the top of the fall and you will need tubing that will carry the water. I have a filter system that my water goes through before it is released to go down the fall.

The rocks should look like a small pyramid with the top rock hiding the hose that the water flows from. I made a mound on the back side of my waterfall to help hide the hose and then planted flowers on the mound. Try arranging the rocks in different designs see which way works best for the area you have. Have fun and enjoy!!