Planning and Constructing Water Gardens

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Water gardens are great options for tranquil getaways.
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Draw your plans on graph paper to help you visualize your entire project.
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A sliced-through view of your project can help you work out how a design should be built.
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A method of concealing butyl liner that gives the illusion of a natural pond.
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This is a selection of the most useful materials.
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These are the essential tools needed to get the job done.
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“Water Gardens,” by Alan and Gill Bridgewater, gives an overview of water garden style and explains how to assess which style is suitable for a particular plot.

Whether your water garden is simple or complex, Water Gardens (Fox Chapel, 2016), by Alan and Gill Bridgewater, guides you through all the key elements to a successful water garden from choosing a project to stocking it with fish. The Bridgewaters have international reputations as producers of highly successful gardening and DIY books on a range of garden, deck, patio and household woodworking designs. This excerpt is from the “Getting Started” section.

If you want the project to run smoothly, you must sort out everything – from who does what and when through to the order of work and what happens if it rains on the day when you are expecting delivery of concrete. If you plan everything out to the last detail, with drawings, lists and schedules, then not only will you get the job done with the minimum of sweat and stress, but along the way you will also probably have a lot of fun and enjoyment.

Deciding What to Keep

When you are planning a new water garden, do not be in a hurry to remove existing trees or large structures; it may be possible (or essential) to incorporate them into your design. If you do have to dig holes, cut down trees or remove structures, then do your utmost to reuse these materials.

Measuring Your Garden

Start by drawing a rough plan (overhead view) of your existing garden. Measure the overall length of the boundaries, critical angles, the position of the house, the gate, other structures, trees and plants you want to keep, the position of the sun at various times throughout the day, and anything else that you think might affect the design. Record these items and measurements on your rough plan.

Additional Features Requiring Planning

Sometimes primary structures like bridges and decks are so complex in themselves that they need to have individual plans in their own right. For example, with a deck you must not only make drawings showing it in plan view, but you must also show all the critical details such as the leg-fixings in cross-section.

Useful Cross-Sections

Cross-section drawings show a ‘sliced-through’ view of a structure and can help you work out how a design should be built.

Drawing a Plan to Scale

After noting measurements on a rough plan (see below) redraw the plan accurately (to scale) on a sheet of graph paper. If the paper is divided into 1 cm (1 ⁄ 2 in) squares, you could use a scale of 1:50, where 1 cm (1 ⁄ 2 in) on the paper represents 50 cm (25 in) in the garden (divide all your measurements by 50). This is your basic plan which should not be drawn on again. Sketch out your ideas for the new garden on photocopies of the basic plan. Once you have finalized the design, draw up a master plan by tracing over the top of the basic plan (tape the sheets of paper to a window so you can see through them and trace over lines). Use felt-tip pens or watercolours to colour in the plan and help you visualize planting schemes. If this sounds like too much hard work, try using a computer software design package.

Planning the Structures

Decide where the primary structures need to go – the ponds, watercourses and sumps – and follow on with the secondary structures – the paths, steps, gates, power cable and pipes. Make sure along the way that you take everything into account. For example, if you have narrow paths and bridges, you must make sure that you can get the lawnmower and a wheelbarrow to all parts of the garden.

Plants and Fish

If you particularly like bog plants or a special type of fish, make sure at the planning and construction stage that everything you have in mind to build is working towards that end. If the fish like calm but muddy waters and the plants need water-sodden, boggy ground, you have to ensure that your design is suitable.

Water and Power Supplies

Most ponds can be topped up using a hosepipe, but for a large pond you may want to install underground pipes and an automatic top-up system. You will need professional help to install an electricity supply for running the pump and lights; alternatively, you could use low-voltage or solar power.

Planning Checklist

• Have you finalized your design, including construction details?
• Have you made sure that your designs are not breaking any laws?
• Are your structures clear of underground pipes and cables?
• Do you need help from friends, relatives or professionals?
• Have you compared quotes for materials and services?
• Have you got the right tools?
• Have you set out the order of work?
• Have you found a way to protect fragile areas of the garden from repetitive over-walking?

Pond Lining

Whatever your choice of pond lining (butyl or preformed), the secret of success is to make sure that the edges are completely concealed. The edges of preformed ponds are best covered with brick or pavers, while the edges of a flexible liner can be completely hidden underground. See how the various projects use different techniques to support and hide the edges.


Foundations and footings are the underground pads of concrete or compacted rubble that support the weight of paving, walls or other structures. The bigger the structure, the thicker and wider the foundations need to be.


Formal ponds and other water features often need walls to retain water (these walls are made waterproof using a liner or tanking paint). Concrete blocks can be used where they will be hidden from view or rendered (coated with mortar) and bricks or stones are often chosen for their decorative effect. Mortar (see below) is used to join blocks, bricks or stones together.


Steps need to be worked out on paper as a cross-section view. In a short flight of steps the depth (‘going’) and the height (‘rise’) of each step should be equal. The rise of a step must be no greater than 23 cm (9 in). To calculate the number of steps and the rise, divide the total height of the flight by 23 cm (9 in) and round upwards. Include foundations and start building from the bottom step.


Materials can be obtained from dedicated bulk suppliers, DIY stores, builder’s merchants and reclamation yards. A selection of the most useful materials is shown below.


Tools can be obtained from dedicated tool shops, DIY stores, builder’s merchants and tool-hire (rental) companies. A selection of essential tools is shown below.

Concrete and Mortar

Concrete — Concrete is mainly used in foundations. Combine 1 part of cement, 5 parts of ballast (ballast is sand and gravel mixed together) and water to make a stiff mixture.

Mortar — Mortar is used in brick, block and stone walls. Combine 1 part of cement, 3 parts of soft (or ‘builder’s’) sand and water to make a smooth mixture.

Safety While you Work

Always follow the manufacturer’s instructions when using tools and materials. Work carefully and slowly and wear the appropriate protective gear as advised. Avoid working if you are tired or feeling unwell. Cement is corrosive, so wear goggles, a dust mask and gloves to protect yourself. Keep children away from work areas.

Reprinted with permission fromWater Gardens, by Alan and Gill Bridgewater, published by Fox Chapel, 2016.