How to design and build a garden water feature and pond system.
The following is a detailed step-by-step guide for the DIY enthusiast wanting to design and install a garden water feature and pond system.
By Shaun Kearney
Part 1 – Designing a pond or water feature for beginners
Ponds and water movement is a science and there is a vast amount of technical knowledge required to design and install an efficient balanced system. When you have finished reading this series you will have a better understanding of the complexities
of pond systems. The design criteria laid down is the same for all sizes of ponds, irrelevant of the size of the water system or the manufacturers’ product.
Possibly the most important step in the whole process of the pond building exercise is the design. Once the design and the bill of quantities have been completed, it leads to confusion when you want to change a design or add another feature.
Do not deviate from the final design.
Here are some ideas that should be discussed before your final decision as well as being included in the final pond design before building begins.
The function of your pond
Looking for something free-flowing and natural in the surroundings to mimic in the pond design. A Spontaneous shoreline with irregularly-shaped rocks and indigenous plants will help create a habitat of natural wonder and beauty for the local wildlife.
Your personality and environment may require a more formal body of water. If so, geometric pond shapes, along with materials such as brick, cinder block or concrete help to maintain an element of order and symmetry within the natural beauty of any garden.
Deep, still reflection pools will tend to magnify the brilliant colors of surrounding trees and larger foliage. Bring in some Japanese garden style elements with their islands, stepping stones and hidden shoreline. This will add a wealth of symbolism and illusion to your environment.
What type of water feature or pond are you about to design?
The decision as to what type of water feature you are about to design and construct needs to be made at the very beginning of the process as there are different pump and filter systems pertaining to the different applications.
- Fish pond: fish need to have a ‘no chlorine’ environment. Salt (non-iodised) is added to Koi ponds to assist in keeping the fish healthy. A pond with a running water feature with falling water, helps keep the water oxygenated as well as keeping the water actively moving throughout the pond, stopping stagnant areas from being created.
- Water feature: a water feature with no aquatic life needs to be controlled for algae. A water feature creates the perfect environment for the growth of algae, scum and a host of different water borne insects. The water stays reasonably warm and oxygenated – two great causes of water going bad. Follow this link for info to control algae in a waterfeature.
- Afternoon splash pool: this type of pool, doubling up as a water feature without aquatic life, needs to be chlorinated either with a salt chlorinator system, an acid conversion system or the standard granular chlorine. This is the pool where you sit in the late afternoon and have sundowners, making your neighbors extremely jealous.
- Swim Pond: the latest environment friendly craze is to have a ‘swim pond’ in your garden. A water feature with aquatic life and used for your daily swim. This has a natural balanced bio-filter system with no chemicals added, same as the Koi pond filter system.
Part 2: Equipment needed to install a garden water feature and pond system.
Equipment relates to the pumps, filters and all other machinery required to make the designed system work. It is always advisable to do a complete shopping list before work begins to make absolutely sure that nothing needs to be added on at a later stage. Another reason for the shopping list is to make certain that you are aware of the costs involved for creating the designed feature.
The equipment selected must be able to operate the designed system efficiently. Pipe sizing is critical as well as the placing of the pumps and filtration systems.
Pipe work for your water feature or pond.
Here are some tips to remember when installing pipe work on a pond or water feature:
- The distance between the weir and the pump unit cannot be too far away.
- The suction line from the pond to the pump must be correct. Reduce the size of your suction line at the pump inlet only and use only 45 degree elbows or long radius bends on the suction line.
- Only use air tight sealed connections. Recommend PVC solvent weld connections left to cure for at least 24 hours before use.
- The flow capabilities through the pump suction pipe work should be at least twice that of the pump delivery. Quantity and velocity of water play a major part in pump efficiencies.
These are some of the factors that influence the pump to work at a greater inefficiency and thus using more power to produce a lesser result overheating a lot quicker and destroying itself.
Pipework or plumbing would be a requirement for:
- Skim Weir (sucks debris off the surface of the water by venture suction through a floating bag)
- Aim flow inlets (to circulate and turn the water over effectively without disturbing the surface if so desired)
- Bottom drain (for pond drainage if a refresh is required.
- Feature pipe work (for the fountains or waterfalls planned)
- Auto fill system (like a ball floating valve or gravity flood system to ensure the pond tops itself up regularly)
- Auto overflow drainage system (a specific planned run off in extreme conditions like heavy rain downpours.)
Part 3: Materials and construction for a water feature or pond.
Very few materials of construction are completely waterproof.
Here are the types of materials that can be used to construct a pond or water feature:
- Standard concrete is not waterproof. Asealant additive must be added to make the concrete more dense like Drikon or Coprox. A colour tint can be added to concrete during the mixing for permanent colouring.
- Depending on who is going to do the installation and what materials have been chosen. Concrete has a curing time dependent on the mPA factor. I would recommend not less than 3 weeks curing before filling with water and using.
- Also not waterproof is your standard garden rock. Rocks are either permeable or non-permeable, meaning that they allow water to pass through them or they don’t, but generally rock is not water proof. Using a waterproofing layer such as a vynal polimer or clear paint on sealant, applied to the surface of the rocks to treat and seal them. This is a reoccurring process though as every 2-4 years you will be required to reseal.
- Applied correctly and allowed to cure, fiberglass is completely waterproof. Fiberglass can be coloured and shaped to suit any application. Preformed fiberglass ponds are also an option.
- Plastic sheeting
- Can be used for the underlay in natural ponds and dams.
- Bidum cloth
- A geotextile cloth used on slopes for anti-erosion and natural run off for canal forming. Natural run offs and overflows for dams and larger ponds in garden environment’s
Electrical installations and equipment must always be treated with the utmost respect. One mistake at this point will most probably land up with someone being killed, a chance that is not worth taking. Always install earth leakage units on any sub boards that are controlling outdoor equipment and install extra earthing points at the sub boards.
All electrical and plumbing work must be done in accordance with the standards set out by the local area controlling authorities.
Part 5: Maintenance and running costs of a water feature or pond.
As we all know there is a cost to having a water feature or pond. I have estimated the costs as follows:
- Electricity @ R1.24 / k W hr
A normal pool pump of 1 hp would cost 93c per hour to run.
- Water @ R 7.00 / k l
A 10 000 liter pond would cost R 70.00 to fill. Depending on the surface area of the water, your weekly fill costs would vary. On an average, a swimming pool loses 25 mm of water per week and the average depth of a family pool is 1300 mm, therefore you would replace your pool water once a year due to evaporation. Taking into consideration that you have to backwash and rinse your filters weekly as well as having moving water, which has a higher evaporation factor, you could be replacing your water twice to three times per year.
On a still surface with the area is being reasonably level, the evaporation factor remains constant and a loss of about 25 mm per week should be expected. Wind and air humidity play a great role in evaporation.
On a moving surface with the water expanding with every ripple created and with each drop of water falling over a feature, evaporation increases dramatically. You will have higher losses with moving water.
Determining the location of your water feature or pond.
Location will determine the amount of unwanted leaves and dust that gets into your pond as well as how warm the water will be if the pond is in the sun or shade. Distance from the pumps to the water feature will be a factor in the pipe sizing for suction and delivery. Consider where the pump house is for the noise factor where the electrical supply is situated.
Where is the ideal position for a pond or water feature in the garden?
Ponds are noisy, so if intended for indoor use we suggest near a communal traffic area for ambiance where the noise is contained or not a problem for other areas of the house. Entrance ways are the most favored.
Consider these factors when choosing a location for your outdoor pool, pond or water feature.
Ponds with their allure and sounds make amazing garden features, both indoors and outdoors.
You’ll probably want to put your garden pond in a location where it can be viewed and heard from as many points as possible: near a patio or deck, an outdoor living area, or a location from where it can be viewed and heard through windows from inside the home.
However, incorrect positioning can create a maintenance monster for you or your gardening service.
Avoid positioning your pond to close to gutters or natural water run-offs. In heavy storms and rain runoff water with debris and chemicals can quickly ruin the water quality of your pond and kill your aquatic life in the pond.
Look for an area that offers a slope. Slopes are perfect for use as a backdrop, and as a foundation in constructing a waterfall.
Allow sufficient perimeter space in your pond planning to ensure that you can easily access any part of the ponds and it’s perimeter for periodic maintenance and planting activities.
Overflow: Ponds must have an overflow area, a low point to control where the excess water should flow out of the pond when there is heavy rainfall.
Light: If you want to grow water lilies or other sun-loving aquatic plants, choose a sunny site. If your pond will be shallow, it is best to provide afternoon shade as it can over heat during mid-afternoon. If you aren’t concerned with growing flowering plants in the pond, a shady spot is fine.
Size: Do you want a mini-lake out back, or a smaller garden pond off the back patio? Do you want a waterfall, and if so, how big and how tall? Do you want a raging river, or just a simple stream or trickle of water over the waterfall?
Electricity: Consider electricity supply for pumps, filters, and lights. If your pond will have a waterfall, it will need electricity – so locate your pond accordingly.
Keep 30-40% shade for you pond, although fish feed better in warm water, shade will protect the water plants and allow the fish better hiding places form predatory birds.
A third of the water surface should be covered by plants, placed in easy to access and care for bank baskets and containers.
You may want to cast a pond mesh for the surface of your pond to prevent children from drowning and birds from eating your fish. Black mesh works best as it hides well.
Minimum water depth we suggest is 80cm, Koi require approximately 1.50m water depth for safe habitat.
Also do not over stock, a good rule of thumb is 1000L for every 1kg of fish.
Water gardens have always been places of refuge, sanctuaries of peace, tranquility and beauty. They should complement your surroundings, your lifestyle and your senses. For this reason, it is important that you create a pond that reflects your personality as well the vegetation that surround it.
Size of your pond or water feature
This is totally dependent on budget available at the time of construction. If you know that you are going to be building your pond over a predetermined budget period spanning a couple of years, design the feature for future expansion. Place extra pipes within the first build to allow for expansion. The design is directly related to the size required as well as the size wanted. Here is where your budget becomes a reality. If you have an unlimited budget, design everything that you can possibly think of, into the feature.
Pumps for your water feature or pond.
The type of pump needed for your pond or water feature will be determined by your design. Your local pump stockist will be available to assist on what type of pump to use or contact KLB Engineering at http://www.klbengineering.co.za/
The main types of pumps are:
- A pump that is operated permanently under water. Borehole type and de-watering types are most common.
- Centrifugal types are most common. A pump that is operated out of water, away from the water feature and usually installed inside some kind of pump house that offers protection from the elements.
- Air pump
- Diaphragm types most common. An air pump injects air into the system.
Filters /sterilization for your water feature or pond.
There are various systems that increase water quality in your pond or water feature:
- Sand filter
- Filters out solid matter larger than 20 micron
- Bio Filter
- Removes Nitrates from the water. Nitrates are what kills KOI and causes algae to grow
- Ultra Violet lamps
- Sterilizes the water. Aids with Algae control and water clarity
- Protein remover
- Removes excessive protein from the water.
- Air venture
- Allows air to be injected into the water assisting with oxygenating the water. Can also be used with the protein remover.
Lighting of your water feature or pond.
Add to the beautification of your water feature by adding lighting in the form of:
- Surrounding areas
Up lighting and or down lighting
Fountain heads for your water feature or pond.
As with waterfalls in your feature, fountains generate splashes and wind may be a problem. Install a control valve on the supply line to the fountain so that you can shut it down when necessary. Illuminate fountains for extra ambience.
Fountain heads can be placed:
- Inside the pond
- On the perimeter of the pond spraying inwards
Part 4: Waterfalls in the garden
The idea of having a waterfall is for the noise as well as the pleasing and relaxing aesthetics created by the water feature. Moving water makes minimal noise, whereas falling water makes a pleasing noise.
Consider these points before planning a waterfall for your garden:
- Continuous flow
- Continuous flow water allows for the water to be continuously oxygenated as well as creating an ongoing noise. The running costs may become a problem.
- Height and width
- The fall height determines the amount of noise and creates a larger splash over problem. The effect of the curtain required is determined by the width of the fall and how far down the fall you want a solid curtain effect. For example if the curtain required is 0.5 m wide x 0.5 m high would need 5 liters per second to maintain a solid curtain effect.
- The shape of the waterfall would determine the amount of noise reflected out of the feature versus the amount of noise absorbed by the water and surrounding foliage.
- Illumination always makes water features look like magic. More than one flood or spot light is a necessity. You are not limited to only having one set of lights to enhance your feature. You can use an irrigation computer with a slight modification to control different lights at different times. The combinations are endless, only limited by your budget.
- Plants – in and out the waterEvergreen and tropical type plants will offer less maintenance through season changes by dropping less leaves.
Choose thirsty tropical plants for around a water feature that always has splash over.
Paving around a water feature, pond or pool can create a fantastic finish. Problems arise when you have water creating constant wet areas on the paving. Algae, molds and staining are common. The danger factor is that the paving becomes very slippery when wet. Consider a gravel bed with good drainage, to surround the splash over area.
Run off drainage for high splash over areas should be designed into the system. Paving angled with the run off toward the feature and then drained back into the system or to waste.
Written by Shaun K Kearney
Technical Manager : Stewarts & Lloyds Irrigation
Tel. -27 (0) 11 608 0155
Sponsored by KLB ENGINEERING
Tel. -27 (0) 11 668 1923/4