How To Design A Pond - What, Where, Why
What? Where? How?
Planning a garden pond can seem a daunting task but it's easy when you know how! Below is some advice to help you design and install the perfect water feature.
Where to locate the pond?
The first step towards building a pond is finding your location. Unless some time is spent choosing the area you can easily end up with a project that becomes far more complicated than you had ever envisaged or with a pond that requires a great deal of maintenance. Below are some useful pointers to keep you out of trouble:
Look for a location where the pond can be enjoyed, this is obviously the reason for building it. This may be at the edge of your patio or a site, which is visible from one of the rooms in your house. Ideally, the intended area should receive shade for around 50% of the day. Ponds exposed to full sun do not give fish any respite from direct light and this can be damaging to their skin. They are also likely to experience algae problems either in the form of green water or the stringy kind commonly called blanketweed, which can lead to high maintenance. Hollows or locations at the bottom of hills should be avoided. Whilst this may seem the perfect spot, leaves and debris can easily blow in, and rain water can bring with it soil and other deposits. Pesticides and fertilisers, which may have been used around the garden, should never be introduced to a pond environment. Avoid overhanging plants wherever possible as these can create two potential problems. The first is that shed leaves, twigs and seeds, can pollute the pond by turning the water black or a tea colour. Secondly their roots can pierce certain kinds of liners. If plants have to be in proximity to the water, make sure they are non-toxic, and opt for a Butyl liner, which can resist pressure from roots better than other liners, and Root Resistant Underlay.
The second step, once you have picked what you hope will be a suitable location, is to look at the practicalities of the area.
- Check the water table in your area. Locations subject to flooding, or with high water tables, can lead to liners rising and structural problems with concrete or Fibreglass ponds. I have personally seen the aftermath of a 100,000 litre (23,000 gallon) concrete pond weighing several tons, lifting and snapping, because the pond had not been filled and the surrounding water table rose.
- Is the area within easy reach of a power supply? Most ponds have at least one pump of some description running on electricity Although it's the industries standard to supply pumps with 10 metres of cable, this does not travel as far as you may think, when it has been routed around the pond and in to the electrical connections.
- Minimise the risk of encountering underground pipes or foundations, by surveying your site either by yourself or employ a professional to do this for you. The aim is to look at the plans of your house and garden for underground obstacles such as hard core, pipes or cables.
The choice of designs and shapes is endless, but ponds can be broken down into two basic styles Modern/Formal or Natural/Informal. Choose one in keeping with the rest of your garden. Use a garden hose or length of rope to lay out the proposed shape on the ground, as an aid to visualising the finished project. The intended inhabitants of the pond will also have bearing on your design. Goldfish will gear their growth to the volume of water available, but Koi will not their growth rate may be slowed, but it will not stop. It is important to match your pond size to the fish you keep. A good guide is a stocking level of 50cm (20") of fish per 1 sq. m. (10 sq. ft.) of pond surface area. Although complex designs may be attractive, they can make construction difficult and lead to dead areas in which water will not circulate properly. They are best avoided.
Koi and goldfish will require pumps, filters and Ultra Violet clarifiers, so the design should allow for the placement of this equipment. Ponds intended for fishes require a sloping base, i.e. shallow at one end and deep at the other. Ideally, locate the pump at the deep end and pipe the filtered water to the shallow end. Ponds with amphibians such as frogs and newts require beaches or ramps for the creatures to climb in and out. Plants can dramatically enhance the appearance of any pond, and suitable ledges to accommodate them need to be included in the design. These ledges are normally at approximately 150mm (6") and 300mm (12") depths, but if you have any particular plants in mind, investigate their growth habit before you start digging. Koi benefit from a depth of at least 1.2m (4ft) and goldfish ponds are ideally over 0.6m (2ft). These depths should account for at least one third the area of the pond, ensuring that the fish have enough space to exercise and to avoid cold air temperatures during the winter. If child safety is an issue, a relatively easy way to avoid accidents is to build upwards instead of downwards in other words, a raised pond. This will obviously add to the project, but will give peace of mind, although children should still be supervised at all times near water.
Decoration in and around the pond
A pond is an attractive garden feature that can have a very relaxing effect. Watching the fish and wildlife explore and feed in the pond can be fascinating, so do not forget to include in your design a viewing area, whether a patio or decking. Plants can dramatically improve the appearance of a pond, but pose some potential pitfalls. If the pond is to be a home for fish and you want the water to remain crystal clear, you must ensure the fish cannot get at the soil. If they can, then they will, and soil will be stirred up into suspension which will create brown water. To avoid this, site the plants in stout baskets, with hessian to prevent leakage and large fist-sized stones covering the soil. Stones will be lighter underwater and so need to be heavy and non-porous. Do avoid stones or pebbles laid directly on the base of the pond, as these form silt traps which will store up trouble. The silt slowly decomposes, clouding the water and affecting clarity. Natural ponds without fish will benefit from a layer of aquatic soil placed on top of the liner. This will allow plants to root and spread more naturally.
The soil dug out of your pond during construction has to go somewhere, so why not use it to create a back drop a rockery with perhaps a waterfall? Do make sure, though, that the soil from the rockery and edges of the pond cannot find its way back into the water.