31°C, New York
Notification products, updates
A raised pond solves two problems at once. It lets you create water where the ground is heavy clay, chalky, or too shallow and stony to dig, and it lifts the surface to a height where you can actually see and hear it. In a small garden that matters. A sunken pond viewed from a kitchen window is often just a dark rectangle; a raised one catches the light, reflects the sky and doubles as a seat.
There are practical bonuses too. Raised walls keep soil and grass out of the water, discourage herons from wading in, and make it far easier to net leaves or tend plants without kneeling on wet paving.
Aim for a finished water depth of at least 45cm if you want a few goldfish, and 60cm or more if you hope to overwinter them outdoors. In a small garden, a rectangle of roughly 1.2m by 0.8m is generous but manageable; even 90cm square will support a couple of marginal plants and a small pump.
Position matters more than most people expect. Choose a spot that gets sun for part of the day but shade during the fiercest midday hours, which helps keep blanketweed in check. Keep it away from trees and shrubs that drop leaves or send roots searching for moisture, and well clear of any buried cables or pipework. Think about access to a tap, because you will be topping it up in summer, and leave a clear edge on at least one side so you can reach the centre.
Timber sleepers are the quickest route to a handsome raised pond. New tanalised softwood sleepers are inexpensive and last well; reclaimed oak is longer lasting and ages beautifully. Avoid old railway sleepers soaked in creosote, as the residue can harm wildlife. Stack them two or three courses high, overlapping the joints at the corners like a log cabin, and fix each layer to the one below with long timber screws or lengths of reinforcing bar driven through.
Brick or dense concrete block gives a more formal, permanent finish and suits a courtyard or walled garden. Engineering bricks or frost-resistant blocks are the sensible choice, laid in mortar on a proper footing and finished with a coping stone that overhangs the water slightly. Whichever you choose, keep the inside face reasonably smooth so the liner is not punctured.
Everything depends on the first course being level. Mark out the footprint with pegs and string, then excavate a shallow trench or, better still, pour a concrete slab if you are building in brick. For sleepers, a base of compacted hardcore topped with a thin layer of sharp sand is usually enough, but the ground beneath must be firm.
Check each course with a spirit level in both directions before you fix it. A pond that leans by even a centimetre will show a sloping water line for years. If you want a wildlife ramp, leave a shallow shelf or a piece of roughened timber leaning into the water at one corner so hedgehogs and frogs can climb out. Finally, line the inside of the walls with a layer of soft underlay to protect the liner from splinters, rough mortar and sharp edges.
Butyl rubber remains the gold standard, with EPDM a close and often cheaper alternative. Buy a sheet at least 1mm thick and allow plenty of overlap: measure the length and width, then add twice the depth plus a generous 30cm on every side for folds and anchoring.
Drape the liner into the empty pond, easing it into the corners rather than forcing it. Weight the edges with bricks and begin filling slowly with a hose. As the water rises, the weight will settle the liner into shape and you can tease out the worst of the folds. Do not trim anything until the pond is full and you are happy with the lie of the material. Once filled, fold the surplus neatly under the coping or hide it beneath stones and paving.
Tap water is fine to use, but it contains chlorine, so let the pond stand for a few days before adding plants or fish. Plant marginals in baskets stood on ledges or on upturned pots so the rims sit just below the surface, and add a couple of oxygenating bunches to keep the water clear. Stock lightly: a small raised pond is not the place for a shoal of koi.
Through the year, the routine is simple:
Do those few things and a raised pond will reward you for years, bringing movement, sound and a little wildlife to even the smallest plot.
Making Beck shares practical, down-to-earth guidance on garden water features: designing, building and caring for streams, ponds and waterfalls. for readers across the UK.
Stay Tuned With Updates
Leave A Comment