You can easily build your own water garden to add interest to your yard. The process isn't very difficult and can be achieved with little expense. We're big fans of the waterfall garden, so here's a step-by-step guide to building your own waterfall right in your own yard!

Your waterfall will run on electricity, so it will need to have its own outlet for a power source. Ideally, the construction of a waterfall should be done by a patio, deck, or porch. If you don't have an outdoor outlet, one will have to be installed by a certified electrician.

Remove all weeds in the area where you will be digging for your pond. Make sure the area is level. Measure the liner you have chosen so you can dig a hole big enough to hold it. Simply invert the liner and trace around it on the ground. Then start digging!

The depth of the hole should be the same depth as the liner and the diameter as close to the actual diameter of the liner as possible to insure a nice, snug fit. If you find your hole is a little bigger than the liner, just fill in the sides with sand.

Sand will also be used at the bottom of the hole, since sand floors provide the stability needed to play with the height of preformed liners. Put about an inch of sand in, so that the top rim of the preformed liner will stand about an inch above ground level -- reducing the amount of dirt that will keep falling into your waterfall pond. You'll be pushing the sand around to get the level of the preformed liner just right.

Next, place the preformed liner into the hole for the waterfall pond. Check for levelness by placing a carpenter's level across it -- both front to back and left to right. Depending on the readings you get from the carpenter's level, it is at this point that you'll have to remove the preformed liner from the hole and adjust its sandy floor accordingly.

OK, prep work is out of the way, it's time to move on to the structure itself. Take a look at the rocks you have. The most important rocks are what might be termed the "spillway" rocks. The spillway rocks are the ones directly over which the water will cascade.

The spillway rocks should be relatively flat as opposed to rocks that are more rounded in shape. They should also have sharp, squared edges. Water will cascade more cleanly over such edges. When rocks have blunt, gently-curving edges, some of the water tends to follow that curve and trickle back under the rocks. The idea behind the selection of spillway rocks for a cascade design is to choose rocks that are most likely to channel the falling water in the precise direction in which you want it to go. How you lay the spillway rocks is also important to this end, as you'll see later.

In addition to seeking out relatively flat rocks with sharp edges, see if you can't find rocks that are slightly cupped. That is, occasionally you'll come across rocks that curl up ever so slightly at the edges, leaving a depression in the middle. The natural channel in such rocks will be greatly advantageous for the creation of the spillways in your cascade design. Their raised edges will help keep the water from deviating where you don't want it namely, behind the rocks.

You'll essentially be building four mini-rock walls around the pot, to box it in. Make a small trench for the tubing to sit in under the rocks, so that the rocks don't weigh it down. This will keep the tubing free, so that you can slide it through the pot up or down, at will. This gives you the leeway that you need, since you won't know at exactly what height you'll want the water spouting out until you've finished laying the rocks. You may have been wondering what the flower pot in the supply list is for. You'll need a pot about 11" high with a drainage hole in the bottom that matches the diameter of your tubing. The pot functions as housing for the tubing within the cascading structure for the waterfall. You could easily substitute something else that might work better and can use either a terra cotta or plastic variety. The idea is to have some sort of housing to hold the tubing in place, while you lay up the rocks all around it. This housing won't show when you're finished: it will lie hidden at the center of your rock work.

After laying a first course of rocks in the front, cover them with a sheet of black plastic. Extend one end of the plastic up to the top of the plastic pot, while tucking the other over the lip of the preformed pond liner and down into the water. Then disguise the plastic with rocks, so that it wouldn't be visible in the pond. The plastic serves the purpose of catching more water than the rocks alone could and funnel it into the pond. Much of the water that would otherwise be lost to splashing strikes against this plastic and falls back into the pond, instead.

Also after laying the first course of rocks in front and just after laying the black plastic, lay one long, flat rock spanning them all and sitting right on top of that plastic. The long, flat rock juts out in the direction of the pond, forming an overhang. It will serve as a shelf for your first spillway rock, so it will be referred to as the "shelf rock."

Invert the flower pot and thread your tubing through the hole in its bottom. Place the pot on the ground (still inverted) at the center of what will be the rock waterfall structure. How far in back of the pond should this be? Well, that depends on the depth of your rocks. You'll want the rocks that face the pond to abut it; if possible, they should even overhang the pond slightly. So if the rocks you'll be using there are 8" in depth (i.e., front to back), the front side of the pot should be about 8" back from the edge of the pond.

How long should the tubing be? Leave yourself with a length that is longer than what you'll need, and trim later as necessary. This will make your job a lot easier! As to where to run it along the ground, choose either the left or the right side of the pond and rock waterfall. As a cosmetic touch at the end of the project, you can go back and hide it with stones and/or mulch.

Typically, when building rock walls, it's a good idea to stagger the seams. Of course, these will be very small rock walls, so it's not a structural concern here. Still, try to do some staggering, if only because it looks better. As already mentioned in speaking of rock selection, after the first course of rocks in the front was down, you put one long flat rock spanning them all. Why? Because this rock's function is to form an overhang, it's a key piece in your cascade design. Using it as a shelf, you'll place your first spillway rock on it, in such a way that the spillway rock overhangs the pond even further. Continue laying the 4 walls, until you've reached the height you desire. Once you're done encasing the pot with the 4 walls, you need to place 2 longer stones across the top (either front-to-back or left-to-right) to span the walls. Pull up the tubing to gain more length, if necessary, and gently sandwich the tubing in between these 2 longer rocks to hold it in place.

Begin trying to position your first spillway rock on top of your shelf rock. It should jut out over the pond even further than does the shelf rock. Ideally, the tip would line up over the middle of the pond, although this is difficult to achieve. Elevate the first spillway rock in the back, to achieve better water run-off. You can elevate this or any rock in the wall by using shims in small flat stones.

Bend the end of the tubing down towards the pond and place one or more capstones over it. It is under here that the waterfall's "spout" will rest, so to speak. By "capstone" I mean a stone that will partially hide the tubing and/or gently press it down against the second spillway rock. Make sure most of the capstone's weight rests on the rocks between which the tubing is sandwiched or on shims, so that the tubing doesn't become flattened. You'll have to play with the level of the spout, as you begin to fit in the second spillway rock.

Begin trying to position your second spillway rock on top of your first spillway rock. Again, elevate the rock in the back using a shim, to achieve a steeper pitch. One way to think of the placement of the 2 spillway rocks is that they're like 2 shingles on a roof. They're both on a slant, and the top one overlaps the bottom one, forming a continuous chute down which the water can pour.

The position of the end of the tubing that forms the spout can now be determined more precisely, as you size it up on the surface of the second spillway rock. Again, pull to lengthen or shorten your tubing, as necessary.

You're ready to fill the pond with water, plug in the pump's cord, and test the flow of your natural rock waterfall. No doubt, you'll have to make several adjustments before you get everything right. The objective is to get the water to fall as close as possible to the middle of the pond, so that you can minimize water-loss from the splashing that will incur.

There is some compromise involved with your cascade design: greater height equals greater visual impact, but greater height also equals greater water-loss as the splashes will be more violent. Another consideration on height: keep your natural rock waterfall in proportion with the pond. A general rule of thumb would be, the smaller the pond, the shorter the rock waterfall.

The entire structure is built with the intent to minimize water loss, but regardless of how well you do at minimizing water-loss, it is prudent to check the level of your waterfall pond water periodically. Should the pond go dry due to water-loss, you'll burn out the pump.

Consequently, you must turn off the pump overnight or when leaving your property. Of course, if you're frugal, you'll unplug the pump when you're not around anyhow, to save money on electricity. Since this water feature is intended only for decoration and for relaxation (it's not a fish pool), there's no reason to keep it running if you're not there to enjoy it.