Garden Ponds

A guide to building your own garden pond. A perfect DIY project to bring together friends and family.

Garden ponds are an attractive feature of a home or recreational property, apartment building or any other property with adequate space. Garden ponds can be both interior and exterior features of a property. In this case, we are concerned with garden ponds for your home garden as these are the most readily accessible DIY projects.

Garden ponds are often home to diverse plant life and aquatic life such as fish, frogs and turtles. They attract birdlife and other organisms. The conventional garden pond relies on water from the local water supply. However, since at Rain for Climate we are primarily concerned with preserving rainwater and the natural functions of an eco-systems, our suggestion is to supply your garden pond with rainwater instead of water from your local water supply. If rain is sparse in your area, you can always have a dual system in place.

The local water warden overlooking the pond and relaxing by catching some fish.

How to go about constructing your own garden pond


There are numerous ways of going about constructing your own garden pond using rainwater. However, with any project, a proper plan is the first step to a successful implementation. Planning ahead saves you time and energy by deciding what you want, what sort of budget you are working with and what is possible within the parameters of your property. A plan helps you determine the type of tools you will require and materials you will need to build your garden pond. Having a plan means you have a rough picture in mind of how your garden pond will look within your garden. One way to go about this is to design your pond on paper and then have it reviewed by experts in your local gardening supply store or someone you trust. Your plan outlines the project from start to finish making it easier to execute the project as well as prepare the necessary tools and materials.

Keep in mind, that since your pond will comprise of rainwater, your location needs to take into consideration both proximity of an inlet as well as an outlet to manage overflow.


Tools and Materials

The basic requirements of a garden pond are an impermeable base layer, adequate plant life for water filtration and perhaps a water filter that keeps the water circulating but is not absolutely necessary. Additionally, there are ready made garden pond kits available for purchase at your local gardening and home renovations store or online at amazon and other internet retailers that include everything needed in a practical package including instructions.

Once you have determined the size and type of pond and its location you can collect the necessary materials and tools. The type of pond and materials used will determine what tools you require if you do not own any garden tools yet.

Given that we are concerned with garden ponds utilizing rainwater. You will need to keep in mind that an inlet pipe and an overflow drain will be required for any type of pond you choose.


Plastic mold pond liners

There are numerous ways to set the foundation for your pond. The most basic and low-cost solution is using a plastic mold pond liner. You can use an existing plastic or steel tub lying around. If you do not have a larger tub lying around, you can always purchase a plastic mold pond liner available in various shapes and sizes. Whichever shape and size of plastic molded pond liner you choose, make sure that it is made of a material that can be cut since you will need to add an outflow pipe near the top of the liner to prevent overflow during heavier precipitation.

Here are the basic steps required:

  1. Mark off the location of your pond with spray paint. Make sure to add 10 – 15 cm (4-6 in.) more space than the actual dimensions of the plastic mold liner.
  2. Dig out the hole for the liner and make sure the bottom is smooth and free of any sharp rocks or roots that may penetrate the plastic mold liner.
  3. Add sand to the bottom of the hole and use a level to even out the surface. Place the plastic mold liner in the hole and make sure that it is not tilted to any side using a level.
  4. Remove the pond liner, dig a trench roughly 20 cm deep for the outflow pipe that will be attached to the pond liner (this outflow pipe should be directed to a raingarden). Fill the bottom of the trench with sand with a slight slope towards the raingarden.
  5. Mark off an area on the plastic mold liner where the overflow pipe will connect to and cut out the hole. Put the liner back into the hole.
  6. After leveling the plastic mold pond liner, fill in the sides with sand until the liner fits into the hole nice and tight.
  7. Connect the pipe to the plastic mold liner and use high quality waterproof silicone caulking to prevent leaks.
  8. Add rocks, wood chips, plants, lights or any other ornaments to enhance the aesthetic appeal of the surrounding area by the pond.

Once you have the above complete, you can decide on the next steps. Either wait for adequate rainfall to fill up the pond or fill the pond with a garden hose. You may also add unique water plants as well as goldfish. However, there are some disadvantages to plastic mold pond liners when adding fish and plant life. To prevent algae, especially when adding fish and other plants as well as utilizing rainwater, it would help to add a filter to ensure adequate water movement. The standard plastic mold liner is fairly small and shallow, therefore it is susceptible to overheating during hot summer days which can lead to further algae. This may affect the health of aquatic life within the pond. Generally, plastic mold pond liners require a bit of effort to maintain water quality as it is more difficult to create an ecological balance.

Aside from the above-mentioned disadvantages, plastic mold pond liners have several key advantages for the DIY project. First, they are cheap and relatively easy to implement. They can be placed above ground or on terraces instead of level with the ground, something similar to an outdoor hot tub.


“Classic” pond using membrane pond liners  

Perhaps the most common approach to building ponds is using a soft pond liner covered with rocks to give the entire pond a natural look. This method can be used for larger fish ponds and natural swimming pools. By covering the entire area with rocks or gravel as well as vegetation, you can give the pond a completely natural look.

Similar principles apply when going about constructing a pond using a membrane pond line as with using a plastic mold liner. A plan helps with selecting the optimal location, required materials and tools as well as expected time required to complete the project.


The construction of a fish pond at an elementary and primary school

Since a picture is worth a thousand words, the following pics highlight the construction process of a fish pond built at a local elementary and primary school in the village of Sarisske Bohdanovce in eastern Slovakia.

A 110m3 fish pond with an outflow stream of just over 100 meters connected to an underground 45m3 water reservoir were implemented in 2014-2015. The pond is comprised entirely of rainwater using a Oase Biotic filter to keep the water moving. Abundant plant life also contributes to water filtration and promotion of bio-diversity. Fish such as Common Carp and Crucian Carp as well as turtles and frogs have been introduced into the pond. The pond attracts birdlife including storks who catch fish for their sustenance. A small natural eco-system has been created by utilizing rainwater collected from the roofs of the school buildings. Additionally, excess rainwater flows into the underground water reservoir which is used for garden irrigation in the summer and irrigation of an ice skating rink in the winter. Given the rising costs of water, the school with the help of Norway Grants was able to “create” an alternative source of water supply free of charge as well as enhance the aesthetic appeal of the school grounds.

An aerial shot of the fish pond comprised entirely of rainwater with the outflow stream (in the upper left corner) which carries excess water into an underground reservoir used for irrigation.

Shortly after the pond liner is put in place, rainwater already starts filling in.

The liner is gradually covered by rocks to give the pond a natural appearance.

Autumn rains have already filled up part of the pond before rocks could be laid throughout the pond providing a minor inconvenience during construction.

The stream connecting the pond with the underground reservoir contains a pond liner along its entirety and is covered by rocks to give it a natural appearance.

After heavier rains, the stream comes to life.

Before taking on a large garden pond project, it is absolutely essential to determine the geological features of the landscape to prevent pond failure or landslides. In the case of this school, an assessment of the proposed pond location was made to ensure that the slope would retain structural stability amidst the proposed load resulting from a 110m3 pond. Afterwards, the construction began with digging out the hole for the pond, shaving away any rough edges and filling the bottom with sand before putting in the pond liner, then bringing in the rocks as cover. Simultaneously, the pipping from the roofs as well as outflow stream were built as well.

With a little bit of creativity and planning, building your own garden pond can be a great experience. Putting your family and friends to work can bring you closer and make it a memorable experience. For those tough bits such as deciding on a filter or type of liner, there are numerous local gardening and home improvement centres with experts who can provide you with advice on your specific situation as each property will have different features that need to be taken into consideration.

 Piping capturing rainwater for the pond is buried below ground.

A small water mill was built by the filter outflow.

If you have any questions or comments as well as pictures and experiences of your DIY garden pond project then please send them to We will gladly share your experiences on our website as well as provide you with any information you need to complete your project.