How To Build A Waterfall For Your Garden Pond
Outdoor waterfalls come in all shapes and sizes and make for emphatic focal points. When mulling over your design options, the main consideration is how to achieve the necessary height and overall size for the waterfall. Too, you will need to select the type of stone or other material that will be used to construct the waterfall. Select materials that will fit in and compliment the surroundings.
Adding a Waterfall or Fountain to Your Garden Pond
Waterfalls can be simple or elaborate, designed to empty into a single pool or pond of water, originating from a flowing stream and falling through several tiers, or cascading dramatically from many feet above the ground. In planning to build outdoor waterfalls, you need to concentrate on two structures:
- The pool into which the water falls
- The cascading structure for the waterfall itself
Once these two structures are in place, you'll use a pump in, or outside the pond to keep water recirculating from the pond to the top of your outdoor waterfall, where it can plunge back down splashing into the pond.
With the pond complete, that means one of the two structures is out of the way. Now it's time to turn attention to the more exciting structure: the cascade design itself. And that means taking a look at the rocks that will be used.
Rocks For The Waterfall
The most important rocks are what might be termed the "spillway" rocks. "Spillway" means the rocks directly over which the water will cascade. In a cascade design you will use two or more rocks, one above the other and so on indicated in the picture below.
The size of your waterfall is another thing to be considered. Design your pond to match the size of your outdoor space; not too big, not too small. Accordingly, design your waterfall to match the size of the pond it will spill in to.
You'll have to choose a pump.
Waterfalls can be constructed atop level ground by using the dirt dug from the pond to create a berm behind the pond. If you are lucky enough, your waterfall can be built into an existing slope on your property. Either way it will require some work. You will need to lay a flexible liner beneath the stones used to construct the waterfall. This liner should drape over the backside of the berm or go above the top rock on a slope and at the bottom should drape over the liner used in the pond so no water can escape.
TIP: Before laying the liner you should stair-step the face of your berm for the waterfall. This will allow you to place the back edge of your flat cascade stones flatly. The front edge of the cascade stones can be held up and adjusted for water flow by placing small rock between the cascade stones.
One alternative to using natural rocks placed atop a liner for a waterfall is to use pre-cast concrete forms that mimic stone for the cascading structure. They're compact and easy to install, as they're simply stacked up over the edge of the pond. You'll Have to decide if these look natural enough for your taste.
In building you waterfall, you should use top quality materials. The little extra money spent will save you future replacement costs and maintenance headaches in the future. The amount you will need to spend for construction will depend on the overall size of the pond and waterfall. Whatever you do, do not skimp on the pump that will generate the moving water over your waterfall and into the pond. To build a reliable and beautiful waterfall you will need the right rocks (in the right places) and lots of moving water!
Plumbing For Your Waterfall
Some like to create a raging waterfall while others prefer the trickle effect. The plumbing for either choice is quite simple and you should have no problems handling this yourself. Once you have selected a pump to create the desired effect for your waterfall, you will then need to select the appropriate size piping to match the pump. Pumps come with flow valves so that you can adjust the amount of flow to achieve just the right effect you desire.
Based on the size of your pond, the volume of water inside the pond, the height of your waterfall and the amount of water you want to spill into your pond, your local pond store professional can recommend an appropriate size pump.
Electricity
Pumps can be custom ordered with cords of various lengths which can be plugged into ground fault outlets from your home or other nearby structures or buildings. If your pump is too far away from an outlet you may need to hire an electrician to install a ground fault outlet closer to the pond.
Pick Out Rocks At Your Local Stone Center
Here's the fun part.
When at the stone center, start by picking out mostly flat rocks to construct the waterfall. Select one larger and thicker flat rock for the base of the waterfall and several other larger flat rocks for the tiers. For the rest of the structure a mixture of sizes and shapes is fine. The rocks used in the waterfall, that will come into contact with spilling or trickling water, should always be angled slightly forward so that the moving water moves in the right direction: towards, and into your pond!
The idea behind selecting 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. In addition to seeking out relatively flat rocks with sharp edges, see if you can find rocks that are slightly cupped. Occasionally you'll come across flat 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.
Load your rocks up or arrange to have them delivered, and head over to the pond supply store.
Pump And Other Supplies
Pumps are available in both submersible and external (out-of-pond models). Reputable water garden suppliers have charts and other information available that can help you select the best model and connecting equipment for your purposes. For the smaller pond, a submersible pump is the most economical. Depending on the size of the pond, a filter and even a skimmer may also be incorporated.
Pumps come in a confusing array of models and sizes.You will need a pump if you are planning on moving water in your pond, whether by a waterfall, stream, fountain, or spouting ornament. Below is information that will help you determine what size of pump you will need for your pond or water feature. It will not matter whether the pond has a liner, or if it is a preformed pond.
If you find the following confusing, don't worry, just take recommended measurements to your pond supply store and a professional can help you figure out what type and size of pump will be required.
Pumps are sized by gallons per hour (GPH) output at one foot of lift or height. Larger capacity pumps are rated by horsepower (hp). Manufacturers offer charts that break down the power of each size pump according to incremental heights of one foot. Some companies label pumps by GPH while others assign letter or number designations that require cross-referencing to charts.
It is recommended that the water in a basic pond be turned between 1/2 to 1 times per hour. A 500-gallon pond should have at least a 500 Gallon Per Hour pump. When sizing a pump for a pond there are a few other considerations. How high will the pump have to lift water? Will there be a waterfall or fountain? Will there be filters? All of these variables reduce the amount of flow, which could affect water quality and clarity.
As previously mentioned, don't let any of this technical information about pumps scare you away! A few simple measurements taken will provide your pond supply source or local pond consultant with the information needed to assist you in choosing the right pump. Just remember this: DO NOT skimp on the pump!
Important Measurements to Write Down:
Estimate the vertical height from the top of your pump to the top of your waterfall or stream and write this measurement down. Add another foot of height (or lift) for every 10 feet of hosing you will be using and write this measurement down.
If you plan to have a stream a general rule of thumb is to figure your stream/waterfall requirement as 150 gallons per hour per inch width of the spillway or channel. For example, if your stream or waterfall spillway will be 10 inches wide, you will need a pump that produces a flow of 1500 gallons per hour (at whatever combined height of the feature and another foot of height for every ten feet of hosing to get there).
This may sound a bit confusing so just write down all the measurements (heights and widths) you can think of so that when you consult with a professional he/she will have these measurement to assist you in determining the size pump you need.
NOTE: It is best to order a pump that will more than handle your needs as pumps come with valves that allow you to reduce the amount of flow.
Submersible Pumps are placed directly in the pond. They are free of distracting noise and can be used to drain your pond when necessary. These pumps do have a disadvantage. The pump seal can rupture, sending oil coolant into the water. This can prevent surface gas exchanges, thereby endangering your fish. We would recommend the new magnetic-drive pump, which avoids the use of coolants. They are more expensive to buy but are far less expensive to operate.
Calculating Water Volume
This is not absolutely necessary for you to do, but the measurements in the equasion will be useful to your pond store professional.
Rectangular Pond: Length in feet x width in feet x depth in feet =cubic feet. Example: 10' L x 6' W x 2' D = 120 cubic feet x 7.5 gallons = 900 gallons
Circular Pond: 3.14 (1/2 diameter in feet x 1/2 diameter in feet) x depth in feet = cubic feet. Example: If your the diameter of your circular pond (from one side to the other) is 10 feet, and the depth is 2 feet, the equation would look like this: 5' W x 5' L x 3.14 = 78.5 x 2' D = 157 cubic feet x 7.5 gallons = 1,177 gallons.
Free Form Shapes: Break the pond down into a series of rectangles and circles and figure the volume of each area separately, then add the volumes together.
NOTE: Each cubic foot contains 7.5 gallons of water, so always multiply the total number of cubic feet times 7.5 to determine the total number of gallons. Write down the total volume of water your pond contains. And remember, you don't have to calculate water volume. If you have the basic measurements as to width, length and depth of your pond, this will be enough information for your pond store professional.
Recommended Tubing Diameter For Pumps To Waterfalls
- 1/2-inch diameter for flows up to 120gph
- 3/4-inch diameter for flows up to 350gph
- 1-inch diameter for flows up to 1000gph
- 1 1/4 inch for flows up to 1500 gph
- 1 1/2 inch for flows up to 3000 gph
Filtration
A well designed larger pond should include filitration. Ask your pond supplier about a filtration system that will work well with the pump you select.
Construction of the Waterfall
Tools and supplies needed to build your own waterfall:
- Round and flat point shovel
- Carpenters level
- Can of orange spray paint
- Plastic flower pot (large)
- Rocks
- Pump*
- Tubing to run from pump to top of waterfall
- Flexible** or rigid pond liner for your waterfall
- Sand
* Remember not to skimp on the pump!
** Buy a quality, crack resistant liner
- STEP 1: Lay a section of liner under where your waterfall rocks will go. Make sure that it drapes down and over the liner in your pond, and up and over the back of the waterfall berm. Keep in mind that this liner will catch any water that happens to drain backwards on the cascade stones (instead of forwards into the pond) taking it back into the pond.
- STEP 2: Lay and situate your tubing with several extra feet in the pond and several feet laying over the top of the waterfall berm. You might need this extra footage later for adjustments that may have to be made during the construction of the waterfall.
TIP: Instead of laying your tubing so that it would be directly beneath the heavy rocks on your waterfall lay it to the side of where the waterfall will be and curl it around the back of the berm to then spill over the top of the waterfall. You can easily disguise it later with rocks or plants.
- STEP 3: Stack Rocks. Lay your bottom rock for the waterfall first. Select a large 2-3" thick flat stone of ample mass and place it for the base of the waterfall. The front edge of this first flat rock should be postioned so that it will jut out over the water of the pond, forming an overhang that sits 3" or more above what will be the water level in the pond. If you need to raise this rock place smaller flat stones beneath it. When you have this first stone in place and set, run some water from a hose over it to make sure it is angled so that it spills into the pond.
TIP: The spillway rocks should be relatively flat (as opposed to rocks that are more rounded in shape). They should also have sharp, squarish 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. A little water trickling under is okay - the liner you placed beneath the waterfall will catch and drain it back into the pond.
Now you are ready to lay the next spillway rock. Select a few small stones close in size and lay them on top - along the sides and back of your base stone. Now, place the next spillway rock on top of these small stones. The front lip of your second spillway rock should be a couple of inches futher back than the front lip of your base stone. Once you have this rock in place perform the waterhose test and make any necessary adjustments to asure that water will spill in the pond.
Do the same thing for additional spillway rock as you did for the second spillway rock. If you look closely you'll see that we used a small boulder with a concave in the center as out top spillway rock. After using small stones to elevate your top spillway rock do the waterhose test again to make sure all spillway levels are spilling properly. Make minor adjustment if necessary using small slivers of flat stone to jack stones up.
You can go as high as you like with spillway stones, however, the higher you go, the more unstable the waterfall will be. Thre to four levels is usually fine for smaller ponds where cementing is not desired.
Install Pump
Place your pump in a cavern under the waterfall, or wherever you want in the pond. Placing it a good distance from the waterfall will provide better circulation. Attach the tubing to the pump as shown in the manual that came with the pump. Your tubing should be laying alongside the waterfall, though you have probably already figured out how to disguise it and cover it up with a few rocks.
Now, go to the back of the waterfall berm and place the top end of the tubing on top of the highest spillway rock. Use a small "cap" stone on top of the tubing to hold it in place as shown in the photo above. You'll have to play with the cap stone a little to acheive good water flow.
Now, 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 into the pond with as little trickling beneath and behind your spillway rocks as possible.
NOTE: There's some compromise involved with your waterfall design: greater height equals greater visual impact, but greater height may equal greater water-loss. 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.
It took two people one day to build the pond and the waterfall you seen in the photos above.
After reading all of these instructions it may seem like a difficult thing to do: to build your own pond. It's not. However, if you feel intimidated don't hesistate to contact and consult a local pond building expert or your pond store professional.
Happy water gardening!
SEE ALSO:
Building A Garden Pond
Growing Aquatic Pond Plants
Japanese Gardening
Rock Gardening
Choose from a Do-It-Yourself project below to view instructions: