Landscaping ideas | Building garden ponds with flexible pond liner
Technical tips: When things are nice and simple, and the ground is firm and flat, he easiest way put in a flexible liner is the standard conservationist technique and is only suitable for informal water gardens:
Take a
sturdy peg longer than the depth required for your pool. Mark the depth on the
peg and drive it into the ground to the expected water level. Excavate to the
level marked on the peg. This is your datum peg, so ensure it remains
undisturbed.
Using your datum peg level, cut a V shaped trench, around the inside of the proposed shape of the pool. The inside edge of this V needs to be no more than 5cm below the level of the datum peg. The depth of the V needs to be just over 25cm deep. The outside edge has to be consistently above that level and needs to slope gently away from the pool.
The excavation should gently slope down at 30 from the V to the required depth.
Consolidate the hole by tamping the soil and remove sharp stones. Line with soft sand and a protective underlay material before laying the rubber or plastic liner material.
If you are completely committed to the natural look then drape underlay in strips on top of the liner. After that sub-soil can be used to be laid on top of liner. Nowadays though, it is thought that in order not to burden future cleanouts with tons of inseparable mud, the underlay it is best left to accumulate sediment and detritus through the normal activity and development of the water garden eco-system. Live with bacteria, the underlay soon becomes obscured under sediment that is unless the underlay floats to the surface in the meantime.
Open out the liner in the hole and fold into place. Collect as many of the creases up together as possible into one fold. don't let the water stretch it into place. Life just aint that simple.
Ensure this underlay does not emerge from the V and go on to end up lower than the water level, otherwise it will end up as a wick capable of siphoning the pool dry.
The V can be filled with soil and planted. It can work as sort of hold for pebbles creating a beach effect or it can contain the concrete footing for an upright timber edging.