Fiberglass Preformed Ponds
- Step 1: Place the pond liner in the spot where you want the pond. Outline this area in the same shape and size as the pond shell with a garden hose or rope. Once you select a fiberglass shell it is too late to change its shape. Remove the pond shell to a safe distance. Add about 2 to 4 inches to the width of the pond outline for room to add and tamp the back fill (Figure 6). Further, add enough distance to the area of turf removed for the addition of edging material if any is to be used. Lay out enough plastic to hold all of the excavated soil (,a href=”fig1.html”>Figure 1). Remove any turf from the enclosed area. At this point use the top soil removed to level the area that is to be the rim of the pond. Use wooden stakes to mark the desired level and then carry that grade around the pond. It is better to add fill to the low side than to cut the high side.
- Step 2: Begin digging soil from the center of the pond outward (Figure 2). Dig down first to the level of the shelves (if any). If edging other than grass is to be used, excavate this area as well. Shelves should be dug 2 inches deeper than the actual shelf to allow for a cushion of sand. Slant the surface where the edging is to be approximately 1 inch per foot away from the pond. Finish digging the soil adding 2 inches to the depth for a cushioning layer of sand. If the pond has a grass edge surrounding it, leave the level of the pond above the surrounding surface at 1 1/2 inches so the lawn drains away from the pond.
- Step 3: Level and pack the bottom of the pond and shelves; cover with a 2 inch layer of sand. Pack and level the sand. Set the pond shell in the hole and check the level of the pond itself. Make any adjustments needed to obtain perfect leveling.
- Step 4: Once the pond is level make sure that it is centered in the hole; begin filling with water and backfilling. Add water at the same time as the soil. Backfilling should be done 4 inches at a time. Add 4 inches of soil (or sand if your soil is too heavy to work easily) into the area outside the pond shell (Figure 6). Once the water inside and soil outside are about level (this could take some time depending on your water pressure) start tamping the soil with the handle of your shovel or some other smooth blunt tool. If your water runs slowly there is no need to turn it off while tamping. Do not overcompact the soil which could damage the shell. Repeat this filling and tamping process until the pond is full of water and completely backfilled. Remember to continue to recheck that the pond remains level as you backfill it. So long as you do not backfill too quickly, the liner should remain level.
- Step 5: Once the pond is filled, edging may be added. If the edging includes concrete do not drop any in the pond water. If much falls in the pond, it should be drained and washed before refilling. Edging the pond must wait until after filling since edging effectively seals the pond in place and prevents any further adjustments. Refer to Step 6 of “Flexible Liners” for further instructions on edging a pond