Dig an informal and wildlife pond from the outside area inwards.
1. Mark out the pond outside rim then mark and dig an area inside this overall rim for an edging shelf to contain rocks/cobbles or other edging materials and the shallowest pond plants.
- This will be outside the area of visual water planned for your pond. The shape of this shelf does not need to match the shape of the pond water.
- The depth of this shelf should be in proportion to your pond size: 6-13cm (3-5″) deep dependent on the size of the edging materials you are planning to use.(Shelf )
- The rocks or cobbles used for your edging will sit on this outside shelf within the linered area so below the finished water level and they should protrude above the water. (So include this shelf area when calculating your liner requirements and add the upright height above the shelf too as this will form the vertical upstand to contain the water).
Historically, pond liners have been recommended to finish horizontally meaning you would always see the rounded lip on the pond edge as water could never cover and hide it. This looks unsightly and allows the sunlight to make this rounded lip vulnerable to cracking and breakdown through UV exposure.
- Finish the liner in a vertical plane trapped upright by rocks or cobbles in a ‘brimming pond’ construction method and this solves the problem of the pond lip being exposed.
2. The hard landscape materials used on the top shelf mixed with shallow water loving plants – shelf will blend the pond edge into the surrounding garden and give a method of escape for the wildlife.
- The liner will finish in a vertical plane held up by the rocks or stones that will finish next to the landscaping around the pond – lawn, patio or border.
- As this will be a very shallow water depth it is called shelf – effectively almost zero water over the top of a mesh basket.
3. Then dig the whole pond area to the depth of the next area of shelving marked out on the ground – the next marginal shelf at 14-22cm(6-9″) below finished water depth – shelf .
- Most of the shelf area designated for plants should be at this depth (2/3rds to 3/4s)
- Cut across the curves to give wide spaces of shelf into the corners – try not to build a thin rim of shelves around a larger surface area of deeper water as this will be unbalanced when you come to plant.
- In an informal or wildlife pond make each shelf as wide as possible so you can use groups of aquatic plants together rather than have them lined up around the edge like a parade of soldiers which is more the look of the formal pond.
4. Then mark out the areas that you intend to dig down deeper – the next shelf depth of 23-44cm(10-17″) below finished water depth – shelf .
5. Finally mark out and dig the deepest section of the pond – 60-75cm deep(2ft-2ft 6″) – shelf