Video by Garden Ninja: Lee Burkhill. This guide is based on the water feature design video from Garden Ninja, presented by BBC Garden Rescue presenter Lee Burkhill. It covers rill design and the principles behind choosing, positioning, and planting around a water feature — clear advice aimed at UK home gardeners. Worth watching before you plan your layout.
1. Decide on the type and scale of water feature
The main options for a domestic garden are a pond, a rill (a long, narrow channel of moving water), a self-contained fountain, or a bubble feature. The right choice depends on the size of the garden, how much maintenance you are willing to do, and whether children use the space.
A rill suits a contemporary, formal garden and is relatively straightforward to build. A bubble feature — where water bubbles up through millstone or cobbles — is the simplest option and safe around young children because there is no open water. A pond takes more planning but supports wildlife.
2. Choose the right position
Avoid positioning a water feature under deciduous trees. Falling leaves decay in the water and clog the pump filter repeatedly. A sunny position encourages algae, so partial shade is often ideal, though some sun keeps the water from going stagnant.
Think about where the electricity supply will run. A pump needs a low-voltage garden cable buried at least 450mm deep, or you can use a solar pump for smaller features. Plan the cable route before you start digging.
3. Plan the pump and power supply
The pump needs to be rated for the volume of water in your feature. As a rough guide, a pump should turn the entire water volume over once per hour. Check the manufacturer’s flow rate (litres per hour) against the approximate volume of your reservoir or pond.
For a mains-powered pump, use an RCD-protected outdoor socket or have a garden circuit installed by a qualified electrician. Low-voltage pumps run from a transformer that plugs into an indoor socket. Solar pumps need no wiring but only run in direct sunlight.
4. Excavate and prepare the area
Mark out the shape with a hosepipe or spray paint and then start digging. For a rill, dig a trench to the depth of your chosen liner plus 50mm of sharp sand as bedding. For a pond, create graduated shelves at 230mm and 450mm depth so marginal plants can sit at the right level.
Remove any sharp stones that could puncture a flexible liner. Lay a 50mm bed of damp sand and then a layer of pond underlay before the liner goes in.
5. Install the liner or container
Flexible butyl rubber liner is the most durable option and lasts 20–30 years. Pre-formed rigid liners are easier to install for simple shapes but harder to fit neatly into odd-shaped excavations. Concrete is an option for formal rills but requires waterproofing render.
Lay the liner loosely and let it settle into the contours as you fill with a little water. Avoid stretching it tight — the weight of water will pull it down, and a liner under tension can split at the edges.
6. Fit the pump and connect the pipework
Place the pump in the deepest part of the feature on a plinth (a brick or small stand) to keep it off the silt. Connect the outlet pipe to the water return point — the top of a rill, the spout of a fountain, or a millstone. Use push-fit hose connectors rather than jubilee clips where the pipe bends.
Run the cable up the side of the feature, through the wall of the liner where it exits, and into conduit for the buried section. Do not pull the cable tight across sharp edges.
7. Fill with water, test, and adjust the flow
Fill the feature slowly and check for leaks at the liner edges and any pipe joints. Switch the pump on and watch the flow rate. Most pumps have an adjustable flow valve — dial it down if the water is splashing out of the feature rather than recirculating smoothly.
Top the water level up over the first week or two as air pockets work out of the system and the liner settles. Once the level stabilises, you can fold and tuck the liner edges under edging stone or turf.
8. Add plants and finishing touches
Marginal plants — iris, rushes, and water forget-me-not — soften the edges and help filter the water naturally. Oxygenating plants below the surface reduce algae. For a rill or bubble feature, plant around the margins rather than in the water itself.
Edge the feature with stone, cobbles, or timber to conceal the liner and give a finished look. A layer of cobbles over the reservoir in a bubble feature hides the sump and looks natural.
When to call a handyman
Call Richard if you want the electrical supply installed safely, the excavation is larger than a weekend job, or you want the whole feature — digging, lining, pump, and planting — completed in one visit.
Want a water feature installed?
The Sandwich Handyman can design, dig, and fit a garden water feature — pump, liner, and planting included.
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