Building a raised pond is not as difficult as it sounds, with the result being an impressive and versatile water feature. You will need a pre-formed liner or other container, and your chosen wall construction material.
Select Your Liner
The preformed liner will help give you a smooth, water-tight base for your pond. You can choose the shape that appeals to you, and then work the walls around that shape. The finish will look professional and clean. They are also relatively easy to use for above ground applications as you will be able to build the dirt up around its base for support.
A basic pond liner will not create the same crisp, finished look as the upper walls may be prone to sliding and moving. However, a basic liner is much less expensive to purchase and will allow you to customize the pool to any shape, depth or design.
Choosing Your Wall Material
The walls of your pond can be constructed using wood, brick or natural stone. There are advantages and disadvantages to all of these choices. Any of them will allow you the flexibility of shape, however while the wood frame will cost far less money to build, it will require more landscaping around it as it will not offer the natural appeal of stone and brick.
If you choose wood, build a sturdy frame allowing space between your frame edges and the pond liner for dirt fill. You will want to plan on placing decorative rocks, stones or plants around the outside of the pond to hide the wood frame. A wood frame will allow you the greatest flexibility in your pond shape.
Another choice is to use retaining wall bricks. These large bricks interlock to each other for a secure, stable wall. Please note that for stability the first row of these bricks should be completely below ground level and hidden from sight. This will prevent your brick wall from shifting over time. While the shape will be slightly more limited than with wood, you can still achieve attractive kidney and oval shapes with them.
Building Your Pond
You are now ready to build your pond. Once the frame is completed, begin with a good 2" to 3" layer of sand on the bottom. This protects your liner.
If you choose a flexible liner, begin using fill dirt to create any shelves you will want in your pond. If you have used retaining bricks for the wall, you will find that the topmost row of bricks is smaller than the lower rows. Fill dirt should be used to fill the area below the upper rows. Gradually slope the fill dirt in towards the center of the pond. Be sure to pack the fill dirt solidly so that your shelves don't shift. The shaped pond can be lined with an underlayment to protect the liner. Finally, the liner can be installed, using large natural stones around the top to hold it in place.
If you have chosen a pre-formed liner, place the liner into the cavity and then use sand to gradually fill in all cavities. Take care to be sure that the top of the liner remains level as it is installed. Pack the sand in as much as possible for a solid base. While the pre-formed liner will not require rocks around the edge to hold it in place, you may want to place stones between the liner and edge of your retaining wall for standing on when you are cleaning the pond.