How to Build a Garden Pond (In 6 Easy Steps)

In this article you will learn how to build a garden pond. Deciding that you would like to build a garden pond is only the very beginning of your journey however.

There is much to consider prior to building. For example, do you want your pond to have fish in it, and if so what sort of fish? This will impact the size, for some fish a depth of 4ft is a minimum the pond must be.

Other considerations include what pond plants you might have as well as what pump and filter you will use.

Maybe you want a fountain, or waterfall, and the best time to integrate such features is while you are building the pond. There is also the thought of the pond being above or below the ground.

Once you have decided what you want, and where it will go, you can start building.

This guide will take you through the necessary steps in the building of your garden pond. (This guide focuses on ponds being built into the ground, but it does include some useful information for those wishing to build a raised pond).

This is a guide only. There are variations in every pond, and you should check with your own project, and if necessary local authority, to ensure everything you are doing is suitable.

Step One – Planning a Garden Pond

Deciding the size of a pond is important. If you only have the space for a pond less than 40sq.ft, then you should consider a mini pond. Something you do not have any fish in, but could be accommodated naturally by wildlife for instance. This would not require the water be kept clear either.

Likewise, if building a raised pond, depending on the size of fish may not be suitable, but you can still make it look smart and formal with aquatic plants. For small ponds (less than 40sq.ft) , your ambitions must be kept realistic, but this does not mean you cannot have an aesthetically pleasing pond in your garden.

For ponds over 40sq.ft, the options are more open. This pond is likely to be in the ground, and you should ensure the location is suitable. For example, plants like water lilies want five to six hours shade free a day.

In addition, you should research what trees you have near the pond too, and find out to see if they can cause damage to some water life with falling leaves. Also, check drawings for underground cables and pipes. Next to a septic tank would be unwise and tree roots can be an issue for instance.

Having decided where, mark out the outline of the pond with string to help you visualise it, and make changes as you see fit. Also, it is at this point you need to think about electricity, and where the wires will be going.

To have clear water, you will need a pump, and you may want a fountain, waterfall or lights.

If you are not confident with electricity, seek professional help, as water and electricity do not mix. Many pond features operate through a 24v transformer from the household’s electricity supply. Running the pond at this voltage is safer, the pump’s performance is not affected and you can save money on the running costs.

The actual shape of the pond is affected by the liner you will use. A rigid liner restricts you to the size and shape already manufactured, but this will be preferred by some. To be bespoke, use a flexible liner, however do not try to be too fancy with the shape as this can be difficult. Instead keep to gentle turns and straight lines. The ideal slope angle is about twenty degrees.

You should by now have a plan for the pond. You will know the dimensions (width, length and depth), what features you will have and where exactly it is going.

Step Two – How to Dig Out Your Pond

This is not a task to be underestimated. For small ponds, they can be dug out with a spade. If you are fit and comfortable doing this it is an option, and if you can seek help, that will make this easier and quicker.

For larger projects often the simplest solution is to hire a digger. It can take a long time to dig out a pond with a spade, so hiring a small digger is a great labour saver.

While digging, you should constantly check you are digging to your plan and it is helpful to leave the outline in place so you have a visual marker. You should have a strategy on what to do with the waste soil too.

Once dug, use a spirit level to check the top around the pond, ensuring it is level. If it isn’t, you can use the waste soil to help level it. You should also take the time to remove any stones or other sharp objects that prevent the pond being smooth. You may wish to use a spade to make a shelf around parts of the pond for plants too. Make sure the shelf is big enough to accommodate plants you plan on putting there, if you choose to.

Step Three – How to Line a Pond

A. How to line a pond with a flexible liner

For bespoke ponds, a flexible liner is the option to choose for a DIY pond. You may hear or read that concrete is the best, but it is also the hardest to reverse should you wish in years to come and has to be done professionally, to an excellent standard. Concrete is also more expensive.

For a permanent pond a decent liner is a must. Buying the cheapest is not the way to go, as it will not last. PVC can last decades and butyl can last a lifetime. Our list of recommended liners can be found here.

When digging out the pond you will remove stones and other matter. Next, you should line the entire pond with about an inch of thick wet sand. You may wish to use a pond underlay too, and combining both is a solution used by many.

Now you are ready to apply the liner. It has to be put in as one piece, with no tears or holes. It is best to do this when there is no wind and with others to help if it is particularly big.

A good tip is to put the liner in the pond, and then leave in the sun for one or two hours. The heat will make the liner more flexible.

Centre the liner, making sure it is in position. Prevent debris from entering the pond. Put stones (or something weighty) at numerous points around the pond on the excess liner to prevent it moving. These stones should not be in the actual pond itself.

Now you should start to fill the pond with water from the hose pipe. Take time doing this, not having the hose on full power. This will allow the liner to stretch to the shape of the hole. You cannot walk away at this point, as you need to remove the stones where necessary to allow the liner to stretch fully to the shape of the pond.

Leave a small gap to the brim of the pond and turn the hose off. Now you can trim the liner, but ensure to leave at least six inches of liner on the surface out of the pond. Then peg the liner down and ensure it is secure.

B. How to line a pond with a rigid liner

If using a rigid liner, by this stage you will have already decided which one you are using, and dug the ground to the liner you have chosen.

It is important when in place that there is no movement for the liner. Before you put the liner in, line the pond with a thick layer of wet sand.

Put the liner in, and first check it is level. A piece of wood over the top and a spirit level is a good way to do this. If it is not, add or subtract sand where necessary until it is.

Once level, you need to make sure it does not move. Timber can be used to help stop it moving (only temporarily, so it can stick out the top). Start filling slowly with water, all the while filling the rest of the space around the liner with wet sand. Ensure all gaps are filled.

Step Four – Edging your Pond

This step depends on how you want your pond to look. It is popular to have the edging in patio or paving slabs. They should cover the water slightly, a couple of inches is ideal, hiding any exposed liner from sunlight.

Be careful no mortar enters the water, as it can harm aquatic life.

You can if you prefer simply cover the edge with grass, just make sure it covers the liner. It can go into the water, as long as it has no pesticides, fertiliser or the like applied.

Step Five – Pond Features

As mentioned in the introduction, be careful with electrics when adding features and seek professional help if necessary. You may have planned for cabling to travel under the lawn, and dug accordingly, or to run along a fence or under decking.

Whatever you have chosen, unless your pond is strictly for wildlife, its likely electrics will be involved. How you add each item depends on what you choose. Each feature should come with installation instructions.

Pond features are rarely difficult to install, and they can make your pond quite the garden attraction.

For example, a lit fountain looks great at night, and a filtration system is necessary for fish.

You may even choose to build a custom waterfall, or install a pre-made one. A fountain needs to be proportionate to the size of the pond, but both can be incorporated if the pond is big enough.

What you do here depends on what you have built, and what you prefer.

Step Six – Adding Life

Mostly this stage is down to personal taste, but it is a good idea to add plants first before adding fish. You will want underwater plants, to keep the pond healthy and provide a more natural environment for aquatic life, and what is on top will depend on what you prefer. Water lilies are a favourite, but other surface plants are available.

Fish should be chosen on the suitability of the pond you have built, not only because of their visual appeal. Keep in mind different fish require different requirements from your pond.  You should not overstock your pond either.

Another thing to consider is protecting your fish from predators, such as herons. A pond net is usually the best deterrent.

Conclusion

In conclusion, building a garden pond has many considerations and steps from start to finish. It is something within the ability of many, and is a very rewarding thing to build, that will last years.

Building a pond also requires many products, ingredients you could say, in order to make it viable. Once finished the pond will require looking after and maintenance, just as most things in the garden. For more helpful tips and reviews please explore Outdoor Guru further.