How to Add Water Features in Your Garden

There are so many different ways of featuring water in a garden that it is important to establish, at the outset, which type of feature is wanted:

1. Fountains, moving water and the sound of water

2. Cascades with rock outcrops

3. A collection of aquatic plants and fish

4. A wildlife ‘natural’ pool.

Assuming that all these features are to be artificial and that the water in any ‘moving feature’ is to be recycled, it is very important that the design ensures complete water-tightness. The three main techniques for holding water are the use of flexible liners, e.g. PVC and butyl; rigid materials like bricks, blocks and concrete; moulded plastic or fibre-glass pools and cascades. One further technique using natural ‘puddled’ clay or perhaps some soil additives, is really only applicable to large ponds and lakes.

Water Features in Garden

In general terms, liners can be used on their own below ground since they mould themselves to the shape of the excava­tion. Once above ground, they obviously need to be contained and this would involve the use of bricks, blocks, concrete or even timber. The structure holding water above ground must always be strong enough to withstand the pressures of freezing and thawing especially in colder districts. For this reason, it makes little difference above ground whether the structure is lined with a flexible liner or is waterproofed in some other way — the overall strength needs to be the same.

FOUNTAINS AND MOVING WATER

Water is moved artificially by pumps: most of these are ‘submersible’ pumps which means they operate under water. Where there are two or more levels of water, the pump should always be positioned in the lowest level, pushing the water upwards. If a surface pump is used, this must be kept out of the water and in a dry chamber adjacent to the lowest water level. Ideally, it should be lower than the lowest water level’s surface.

There are some interesting ways to feature moving water: bubble fountains, foam jets, a spouting lion’s head, a millstone, an old- fashioned hand pump with continuous flowing water and so on. With all these features, it is important to ensure that the pool into which they flow or emerge from is large enough to catch all the water, even on a windy day.

CASCADES WITH ROCK OUTCROPS

From both a design and construction point of view, it is important to realize that rocks cannot be joined to concrete to make a permanently waterproof joint. A cascade-type water feature which looks as if it is made entirely from rocks, will usually be made substantially from rein­forced concrete, with rocks added as a disguise. Liners are more difficult to use under these circumstances because any rocks which are placed on the inside of the pools could damage the liner. An exception would be a long thin stream with cascades. Concrete is likely to crack under these circumstances, so a liner, treated with care, could be more successful.

The depth of water in a pool at the foot of a cascade will affect the noise the water makes. The deeper the pool, the deeper the noise will be. As with fountains, it is important that water does not splash or blow out of the system. In a system where several pools or streams are joined by waterfalls or cascades, the pump would normally be sited in the lowest pool. When the pump is switched on, especially after a dry spell, it takes water from the lowest pool and pushes it up to the top. Each pool is then filled to overflowing until, eventually, the water returns to the lowest pool. By this time, a good deal of water will have been redistributed throughout the system and the level in the lowest pool will have dropped significantly. It is, therefore, important to ensure that the lowest pool is large enough and deep enough to withstand these variations and that it is designed in such a way as not to look odd when the water level has dropped.

A COLLECTION OF AQUATIC PLANTS

Where a wide selection of aquatic plants is needed, different depths of water will have to be provided. This is usually done by building shelves into the pool so that different plants can be given an appro­priate depth of water. This idea can be extended further by planning areas which are only partly submerged for bog plants.

In general, ornamental fish will need a minimum depth of water around 45 cm (18 in) but certain breeds may have further special requirements relating to a certain volume of water per fish.

Water Features Garden

A WILDLIFE ‘NATURAL’ POOL

‘Natural’ or nature pools are best constructed from a liner. The idea is to bury the liner at least 150 mm (6 in) below ground so that the pool is mud lined. This means that, as the mud emerges above the water’s surface all around the edge of the pool, it can be planted with bog plants, sedges and small rushes. So long as the liner is brought out just above soil level, so that the wet soil inside the pool does not pass its water across to the dryer soil outside, the two soil levels can be approximately level, making it easy for creatures to move in and out of the pool. Eventually, once the plants have grown into the soil on both sides of the liner, the effect looks remark­ably natural.