How to create a pond or water feature in a garden of any size

Whether you live in the country, city or suburbs, there's plenty of scope for self-building a traditional pond 

Introducing a pond into your landscaping can be a transformative, shimmering void in the solid surfaces and breezed stirred planting, attracting birds, wild mammals and human water gazers with hypnotic certainty. 

The various sounds associated with moving water, and the indicated promise of fish, newts and pond skimming fairy creatures; it’s such a draw and can be executed as an Earthborn natural spring or as stiffly formal as a Renaissance pleasure palace.

There are watery solutions for even scary sloping sites and tiny suburban plots.

Some homeowners have gone for full moat magic, and If you’re interested in creating a natural swimming pond, take a dip in my earlier feature here. Is there’s a giant immersion switch in the garden shed to get the wet-suited warriors through the colder months of an Irish year: irishexaminer.com/lifestyle/arid-20348433.html.

POND POWER

You can put a conventional pond anywhere that you can access it on all sides that are not truly boggy. Can you reach the spot with the necessary power for aerating pumps, filters, UV filters or lighting? Larger waterfalls moving 1000s of litres per hour may require a soil filter. Some waterfalls will turn over their entire capacity of water every hour. For less elaborate setups, wireless solar-powered pumps and small (50cm) fountains, alone or matched to a battery to take them through the night, can remove the need for any mains help.

Fill the pond before you cut your liner.Pictures: iStock

With controlled turbulence, pumps aerate the water and move it across to the filter. Check the wattage of any electrical device to figure out its potential running costs and look for the dB noise level on the spec too. for Your supplier should be able to talk you through flow rates and ‘lift’ to get the right pump (solids handling to manage the filter) for the volume, features and habitation of your pond, using one or more pumps for independent performance. Ensure you know the width and headage of any waterfall.

SITE AND SHAPE

To lay out the pond before slipping disc, use a garden hose or trickling white sand to site the pond in semi-shade (too much sun will just crank up your algae count). If you’re looking for something urbane; a straight-sided pond, set into the ground or more typically with raised walls can form part of stunning, hard landscaping. Generally, if you want to indicate natural features, rambling curves are key. Go back in the house. Bound upstairs. Can you still see the pond? Be wary of areas where there may be any undesirable run-off into your pond.

As my parents have aged, a raised Japanese style water feature with the surface at knee level behind retaining stone walls offers a lovely place to sit without stooping to watch and feed the fish and to fidget with the pumps and planting in a raised wetland style terrace. Flanked by steps, our latest project allows for water to fall down the ramped garden to the pond, combining natural with idealised landscaping. If your skill-set is up to laying a small concrete pad and setting up a retaining wall, put in some sweat equity.

SIZING

The size and depth of the pond will be dictated first by the types and number of any fish you might include. Dedicated wildlife ponds are best left fish-free. If you’re determined on specimen koi carp (my father has some scaly old pets as long as my leg) a pond of 1.5m-2m will be predetermined to allow them to go deep enough to keep warm and semi-hibernate in winter. Don’t over-populate. Once they grow to specimen size and start breeding, apart from unpleasant crowding, the pump and filters will be thrumming loudly to keep the water clean.

A few goldfish will thrive in 1m-1.5m of water and if you couldn’t be bothered with feeding a shoal of anything, a 0.6m dig out will still deliver enough depth for sighing and dreaming by its edge, providing welcome support for your horticultural wildlife. Ramped edges with shallows, allow for a variety of planting positions and semi-aquatic plants that like their toes in the water rather than total immersion and will ensure that smaller animals and birds don’t drown. Ensure you have that ratio of sufficient depths to shelved shallows keyed into the plan with the main edges excavated and compacted to slope inward keeping the sides stable.

DIGGING OUT

A flat spade and a strong back will suffice for a simple pond without blockwork. You will want to keep the sod and soil to create surrounding features, perhaps a site for a waterfall, a bank around the pond or shelving at the water’s edge. Ensure there are no utility lines set under the lawn or drainage pipes in your way before cleaving the ground. Remove stones that could pierce the liner once heavy with water. Use a long piece of wood and a spirit level to check the pond is level, side to side on completion. Another solution to raise the sides? Consider creosote-free timber sleepers bolted together and fully lined.

LINERS

With the site dug out correctly, and presuming we’re using a flexible quality butyl liner you will need: soft underlay, a quantity of soft sand, edging material and as much familiar support as you can beg for.

Straight-sided ponds can be lined with welded metal “tanks” dropped into position or a combination of concrete/stone/sand bedding followed by a commercial liner secured by the edging material (flat stones, pavers etc.) in pleats. Rock shelves formed by the edging can hide your liner neatly.

There’s a bit of science to research as you construct the ground for the liner; what’s termed the capillary barrier. Basically, this is water retaining trench or other device such as the liner being set under the lawn or a gravel coral, to keep the inevitably soggy edge of a sunken, ground-level pond away from the surrounding footing. Don’t ignore it. Nitrate based fertilisers leaching into a pond from the lawn will turn it green and could murder your fish friends.

For flexible liners, there are easy calculators online to help you determine exactly what you need to buy using determined lengths, widths and depths of your pond, and obviously including a generous overlap.

Another pro tip that’s often repeated by landscapers is to set up the liner as the pond is filling from the hose before cutting it.

The weight of the water will settle the liner into the underlay and sand bed on the bottom and sand lined shelves, so that you can get on with folding and securing the edges with flat stones without the liner ending up as taut as an elastic band.

PLANTING

Together with pumps and filters to move, oxygenate and crucially, clean the water, the right plants offer a passive solution that not only look great but that will save you work. Perennial marginals can really help to pull damaging nitrates out of the water. Don’t overstock or it can unbalance the ecology of the pond. They can be introduced in multiple ways suited to their natural level in the water, set into low walled planting pockets and even segue onto a bog garden with graceful sentries like Lobelia cardinalis and flag iris/Iris pseudacorus. Baskets filled with aquatic compost allow plants to be neatly contained and moved when required.

Otherwise, you can plant straight into the pond bottom. Most people over-plant their pond, not realising what a summer of sunshine and fresh water can do to those lilies and floating and submerged species.

Some plants like the popular floating water hyacinth/Eichornia crassipes will die back in the autumn, but others will paddle on most of the year. As the blanket weed and intended planting takes over, be prepared to roll up your trousers and get in to winnow them out in hanks if they cover more than 50% of the water surface — great gifting ideas for fellow pond pals.