Many clients I’ve worked with have requested a water feature in their garden design. I always find it an appealing part of my work when I’m asked to include one. Some of these features have been bespoke designs and some have been off the shelf self-contained systems but every one of them has added something special to the garden.
So why have a water feature ?
The sight and sound of water can induce a flood of neurochemicals that promote wellness, increase blood flow to the brain and heart, induce relaxation and help with creativity.
Undesired noises, for example from roads, can be attenuated by the sound emanating from a water feature.
Water features help to increase biodiversity in a garden by attracting wildlife in the form of insects, amphibians and small mammals.
Many studies have found that blue and green, colours inherently associated with water, are also associated with calmness and relaxation. The colour blue, in particular, is known to have a calming, relaxing yet energising effect on our minds and bodies, due to its specific wavelength. Another reason why the colour soothes us so, some scientists say, is because we evolved on a planet that is mostly water and sky blue.
Typical types of water feature
Circulatory systems pump water from a reservoir along pipework to an outlet at a higher point. The outlet could be in different forms for example a fountain head, a waterfall or the top of a rill. The water then flows back into the reservoir. In a small circulatory system, the reservoir has to be large enough to contain the pump whilst ensuring that the pump will always be underwater. It also needs to be large enough to store the volume of water that would otherwise be in the system when it is not operating. The type of pump needed depends on the flow rate of water a pump must deliver (e.g. in litres per minute) and the total head height it must overcome to deliver the desired flow rate. In a circulatory system, the head height is determined by the difference in height between the reservoir water level and the outlet point. Additionally, the pump may have a filter attachment which helps to purify the water.
Although wildlife ponds can be part of a circulatory system, they can also be examples of typical non circulatory water features. These types of water features may or may not have a water filter and / or pump (if so, usually for providing a small fountain where the pond is the reservoir).
Bespoke or non-Bespoke ?
Self-contained circulatory systems are readily available for varying budgets from vendors although there will usually be a limit to the size due to what is possible to be easily transported. Prefabricated ponds are also available but again will be limited by size because of transportation.
Bespoke circulatory systems and ponds are usually more expensive overall than non-bespoke ones, but not necessarily. The advantage of a bespoke system or pond is that it can be designed to fit exactly what is needed. Rills and large ponds have to be uniquely designed as these cannot be purchased as standard products.
Potential problems and how to mitigate them
Evaporation and spillage
All water surfaces will suffer from evaporation on a dry warm day even if in a shady area. Water features that have fountains, blades or other types of waterfalls can also suffer from spillage especially on windy days. This means that the water reservoirs or ponds will need to be topped up periodically. This can be done either manually e.g. with a hose pipe or automatically with mechanical or electronic top up systems. Alternatively, waiting for an adequate rainfall will also help.
Whether the water feature is either a circulatory system or not, in the event of too much rain there must be an overflow mechanism which allows excess water to drain away. This could be as simple as allowing water to spill over the edge of the feature or pond to (which could make the immediate area very damp and sodden) to installing an overflow mechanism which takes excess water away to a suitable location e.g. to a garden border or to a small soakaway. In the UK, draining excess water into water courses will usually require permission from the landowner, possibly the Environment Agency and / or local district councils.
It’s important to keep the water in the water feature clean and clear especially in wildlife ponds and there a number of ways of achieving this.
UV filters (for ponds and circulatory systems):
With a UV filter, the water is pumped and passed along a lamp, which radiates ultraviolet light killing any harmful organisms, for example algae which could otherwise grow restricting the amount of oxygen in the water.
Oxygenating plants (for ponds):
A more environmentally friendly approach would be to use oxygenating plants. Oxygenating plants are considered one of the most important groups of plants for a pond. An oxygenator is a term applied to a wide variety of fast-growing plants, originally so named because it was thought that they give out oxygen constantly though like all plants they give out oxygen during the day and use it up at night. Their primary benefit in a pond is their ability to grow rapidly, using nutrients that algae, such as blanketweed, would use. By occasionally thinning the oxygenators in the pond, a healthy balance can be maintained.
Chlorine tablets (for circulatory systems, not ponds !):
The least environmentally friendly option is to use chlorine tablets, similar to using chlorine in a swimming pool. These will kill any organism in the water. Evidently, these can only be used for pure circulatory systems !
Leaks can be very frustrating and time consuming to resolve and generally there is no easy answer to resolving a problem once it occurs. The best thing to do is to avoid getting a problem in the first place. This will mean, especially for bespoke water feature projects, ensuring that the design specifies materials and products that are high quality and that the contractors constructing the feature have very good knowledge of this type of construction. Non bespoke systems will generally have a guarantee but again it is best to consider sourcing a very good specification product.
Rob Howard, Garden Designer