12 Steps to Build a Small Pond
Create your own backyard oasis.
By Oscar H. Will III | Illustrations by Marilyn Cummins and Ray E. Watkins, Jr.
Filtration system: Pump, filter box and filter medium, pump and return tubing. GFI outlet near pond or exterior- grade extension cords plugged into GFI circuits (for temporary use).
Liner: Synthetic rubber sheeting suitable for pond lining. Geotextile fabric for under liner. Both sized to your excavation.
Rock: Flat stones work best for lining and stacking, as well as for curbing. Save the larger pieces for curbing or use curbing stones. Limestone and flagstone work well.
Sand: Washed sand sourced from your local pit or bagged from the box store.
Plants: Potted aquatic plants for the shelf and potted water lilies for the deepest level
WEB EXLCUSIVE: Scroll past the main story for more on winterization and overflow.
Picture yourself relaxing next to a small pond of your own design, built right into your yard’s landscaping. There are many ways to construct a water feature, and the good news is they don’t all require heavy equipment, surveys or a permit. We’re going to consider one method that gives you the most flexibility—a rubber-lined depression dug to the shape and depth you desire.
These instructions offer a framework for creating your own pond. If you want to create a stone waterfall or a fountain as the return route for the filter outlet, go for it. Before you begin this project, you should investigate which filtration system you want to use and how to size it appropriately. If you don’t want fish, you may not need to install a filtration system.
- Locate your pond where it will enhance your existing landscape and where you will be the most likely to enjoy it. Call 811 and consult utility maps to be sure it is safe to dig. For best results, locate the pond where it will receive at least half-day sun (so plants can grow) and not receive significant runoff.
- Use a long, flexible rope, garden hose or chain to create the pond outline on the ground where you intend to build it. For a more natural look, make the outline irregular rather than a perfect oval, circle or square. Mark this perimeter outline with spray paint, closely spaced flags or chalk.
- Use your loader and backhoe to level the area and excavate the pond to a depth of about 10 inches throughout, while sloping the sides. To create the first terrace or shelf, suitable for attractive aquatic plants, trace a perimeter on the bottom of this first shallow excavation about a foot inside the outer pond edge.
- Excavate the entire area inside the tracing created in Step 3 about another foot in depth (22 inches total depth from ground level), making sure to slope the sides again. This depth is sufficient for small fish and lily pads, but even deeper is better for temperature control.
- If you wish to have a deeper pool somewhere in your pond, trace the area and excavate it as in Step 4. Lastly, dig a pump pit large enough to house the pump in the pond’s deepest pool.
- Line the horizontal surfaces of your pond excavation with an inch or so of sand if your soil is rocky and/or contains sharp roots that might puncture the liner. If your ground is particularly rough, add a protective layer of geotextile material beneath the liner.
- Measure the maximum length, width and depth of your pond. Plug those values into an online estimator to calculate the size liner you need, the rough volume of water your pond will hold and to size your filtration system.
- Install the liner in the excavation by folding and stretching to get it to lay smoothly and conform to curves. Locate the pump’s hose where you want it to exit the pond, route it to the center of the pump pit, and hold in place with stones.
- Stack flat rocks along the perimeter of the pond’s bottom layer. Stack another layer along the perimeter of the layer below the plant shelf, building this stack up level with the plant shelf. Then pave the expanded shelf with flat stone, building it up along the pond’s top perimeter. Using all this stone is not mandatory, but it is aesthetically pleasing.
- Locate the filter housing in a hidden spot outside the pond that is easily accessible, and connect the pump hose and the outlet tube. Locate the outlet tube where you want the filtered water to re-enter the pond, perhaps as a waterfall. Hold it in place with the curbing stones you will put on top of the liner completely around the pond’s perimeter. Trim excess liner that extends beyond the curbing stones.
- Set the pump on a flat stone at the bottom of the pump pit and connect the pump hose. Route the power cord from the pump to the outlet, tucking it between stones to camouflage it. Many folks supply power to their filter system using exterior-grade extension cords plugged into GFI circuits. We recommend doing that for the short term or if you will only run the pump intermittently. A better option is to have an electrician provide you with a GFI outlet nearer the pond.
- Fill your pond, turn on the pump, and in a few days, you can set potted aquatic plants on the shelf and potted water lilies at the deeper location. In time, you can add fish, but be aware that some fish are hard on the plants. With the filtration system in place, you should have no problem maintaining fish, except perhaps in extreme heat or if the pond freezes in winter.
WEB EXCLUSIVE: Winterization and Overflow
Winterization: If it is super cold where you are and the pond is likely to freeze more than a few inches in depth, remove your plants and fish and bring them indoors, or install a stock-tank heater or bubbler to keep the pond from freezing. You can then pump it down to about 25 percent of the original depth, cover it or just leave it, but remove and disconnect the pump, and remove and drain the tubing and filter, placing these items indoors or at least into the garage.
Overflow Channel: If your pond might be prone to flooding, you can install a rock-lined overflow channel at the lowest point of the pond’s bank. The channel should be shaped to allow water to overflow the pond and drain away in as slow and broad a manner as possible to avoid erosion issues. In some cases you can rock line the first several feet and then grade it to discharge broadly onto a grassy swale.