Installing the Pond Liners

Leveling the site will create an attractive garden pond and make the whole installation process easier. It will also ensure that once filled, there will not be any unsightly exposed areas of garden pond liner around the perimeter.

• Knock in leveling pegs 4 to 6 feet apart along the pond outline. Make the first peg level with the intended water level of the finished pond and adjust all pegs accordingly, using a straight-edged piece of wood and a spirit level, adding or removing topsoil until the tops of all the pegs are level.
• Dig a trench outside the outline, 6 to 8 inches deep and as wide as the edging paving. Lay a pipe across the trench opposite the waterfall end, which is wide enough to carry the pump hose and any electrical cords. Lay the concrete collar in one go, leveling it off as you go, using the leveling pegs as a guide. Allow for the thickness of the paving so that it will sit level with the adjacent ground on top of the concrete. The garden pond liner will eventually run on top of this, sandwiched between the collar and the paving. Allow 48 hours for the collar to set.
• Place the pond in the hole. Check to see if it is level by using a plank of wood and a spirit level.
• Mark the ground inside the collar where you intend to make a shelf for marginal plants. Do likewise for midlevel and deep-water areas. Shelves should be at least 12 inches wide and 10 inches deep below the top surface of the collar. Midlevel areas should go down to 15 inches and the deepest areas should be at least 18 to 24 inches deep (the deeper the better). Steep, near-vertical sides will give the garden pond a greater volume, which is desirable. Use the excavated soil to construct the waterfall, compacting every 12 inches to give it a good foundation and forming the stepped cascade out of the compacted soil.
• Measure the maximum length, width, and depth of the pond to determine the area of the pond liner required. You will also need the same area of protective underlay. Clean any loose soil from the hole, and check for stones and roots. Line the hole with underlay, and spray gently with water to help keep it in place. With the help of someone at each corner, walk the pond liner over the hole. Once it is in place, anchor the liner with stones or bricks placed around the edge. If you do this on a warm, sunny day, the pond liner will be supple and easy to work with.
• Fill the pond with 6 inches of water. This will start to mold the pond liners into the hole. As the liner starts to find its shape, gather any small creases into larger folds, making the liner as crease-free as possible. Make sure there is sufficient liner for covering the waterfall. Continue to fill the pond to the top. It may be necessary to get into the pond (make sure and take your shoes off so you won't puncture your liner) so that you can work out all the creases effectively. If you are able to fill the pond through a water meter, you will know the exact volume of your pond, which will then tell you what size water pump and water filter will be required.
• Install the pump and filter. Place a submersible pump in the end opposite to the waterfall. Run the cable to the nearest power point and the hose around to the back of the waterfall, burying both. The location of the filter will be determined by its type. A pump-fed trickle filter should be placed above the waterfall and concealed in rock work. A pressurized filter can be buried anywhere convenient. A skimmer filter will be adjacent to the pond. Ensure that all power is connected through a ground fault interrupter.
• Depending on what material you choose for edging, position natural free-form rock or paving around the edge. If paving stones are your choice, place these on a bed of mortar on top of the concrete collar. The liner must come up behind the rock or paving to enable the pond to be filled all the way to the brim. If this is done correctly, you will avoid an unsightly border of liner being visible just above the surface of the water. If you use natural stone around the edge, remember to leave a gap for the electrical cord and hose.