How To Add a Water Garden To Your Backyard

How To Add a Water Garden To Your Backyard

If you can’t get enough of gardens in your personal space, or enjoy the zen vibe water brings to your outdoor surroundings, a water garden might be just the thing for you. Similar to a standard garden in size, water gardens can be installed in just about any shape or variation, and if you plan right, you’ll revel in it for years to come. 

Here’s what to consider when deciding on adding a water garden to your backyard:


Water Garden Definition

As the name suggests, water gardens are aquatic gardens that host water-loving plants, and sometimes fish. Water gardens can be any size or depth, but usually remain smaller and shallow because aquatic plants prefer specific water depths generally less than 24 inches deep.

water garden ideas 

Types of Water Gardens

Fountains —

This is the most basic of water gardens and technically, is more of a water feature. However, if plants are added to the fountain’s tub, it’s referred to as a water garden. Pumps and tubing are usually built into the fountain.

Container/tub garden —

A container-pump system can create container water gardens. Like fountains, this type of water garden has minimal upkeep, but still is a pretty addition to a backyard. If you go with this scenario, choose a container that is watertight and large enough to accommodate the plants you use. You can even introduce fish into container water gardens as long as there is a pump to oxygenate the water.

Most container gardens are lined with plastic, with soil placed in the bottom of the container and plants installed in it, or pots filled with the different kinds of water plants are submerged in the container.

In-ground water gardens —

In-ground designs are usually what you picture when you imagine water gardens. This type uses a rigid or flexible liner that is placed into a hole in the ground and filled with water. In-ground gardens most often come in round, kidney or teardrop shapes and can measure up to eight feet or more across. Rigid liners are usually less forgiving and trickier to install as it can be a challenge to get the liner level and to conceal edges.

Flexible liners are easier to install and can conform to the shape of the hole dug in your ground. Flexible liners can also work with a variety of edging options to hide the rim.

Above-ground water gardens —

Water gardens in your backyard

Above-ground water gardens sit on surfaces like the ground, patio, or deck, and are larger than a container garden but smaller than in-ground designs. Above-ground options are good if you have rocky or clay soil because these soil types can be difficult to dig.

Above-ground designs can use flexible or rigid liners.

Ideas for water gardens


Key Elements of a Water Garden

At the very basic level, you’ll need a reservoir or some sort like a container or dug hole with liner, clear water, plants, and fish if you choose to add them.

Here are the water garden elements in more detail:

    • A rigid or flexible liner. Rigid liners are made of strong, black plastic or fiberglass, and flexible, cut-to-fit liners are comprised of PVC or butyl rubber. Pre-formed liners are quicker to install, but flexible liners allow for greater design options.
    • Underlayment to prevent leaks from objects striking or pressing or sharp rocks in the soil.
    • Fish for beauty and to control mosquitoes.
    • Plants for decoration and to shade the water and keep it clear and cool.
    • Edging such as small boulders or flagstones to hold the liner in place and prevent soil and mulch from washing into the pond.
    • Shelves for shallow-water plants.
    • Skimmer-pump-filter to pull water from the surface to filter out debris and aerate the water for healthy fish.
    • Options such as waterfalls if you choose.


Planning Your Water Garden

Before building your water garden, do some research. Read, get online, take garden tours, look at portfolios and visit jobs to find exactly what you want. 


    • Start by measuring and marking the ground area where the pond is to be placed. If you don’t have a lot of space, you can even choose a long, slim water garden design placed between other backyard elements.
    • Choose a spot away from large trees and shrubs, because underground root systems and overhead falling leaves and twigs can muck up your water garden.
    • Avoid low-lying spots because rain or runoff can flood your garden.
    • Locate a level surface for best water flow.
    • Choose a space that gets five-to-six hours of sun a day because water plants bloom in full sun. Some partial shade is still OK as algae also blooms in sun and you want to discourage algae growth. 
    • Find a place near an outdoor power outlet for water garden features that use electricity such as a pump, fountain, or filter. Remember that all outdoor wiring needs to be protected by GFI that shuts off power when circuit problems occur to prevent shock.
    • Check that your chosen spot is nowhere near underground lines, pipes, or cables. Call the utility company to inspect your site for any buried lines. This service is usually free.
    • Ensure you’ll have good visibility of your water garden. You want to enjoy it and also keep an eye on safety.
    • Make sure you check with your local county or city codes regarding any restrictions regarding building your water garden, such as depth.
    • Decide if you want fish and waterfalls or not because these elements require different design considerations and treatment.
    • Make sure there is plenty of room for landscaping around your water garden.  


Building a Water Garden

At its simplest, for larger water gardens, you’ll need:

    • A tape measure
    • A hole in the ground if you’re going for an in-ground design
    • A basin (container, liner)
    • Filter box and pump
    • Tubing to fit the pump (check the pond pump box to see what size tubing the pump requires)
    • A level
    • Shovels
    • Rocks and stones for decoration
    • Outside electrical outlet

The basic process for building is:

    • Dig
    • Install pump, filter, tubing
    • Install layer and underlayment
    • Position stones, install edging
    • Fill with water

Keep in mind that proper filtration is critical. You’ll need a filter that runs all the water in the garden through it every hour. Check to see that your filter is the right size and power for the size of your water garden.

Also, as you lower the basin into the hole you dug, make sure that its rim is even with the surrounding ground and use a level so that the water will be evenly distributed in your water garden. It’s advisable to test for cracks by partially filling the basin with water.

Add rocks to bottom of the basin if you want, and layer rocks, plants, or crushed stone around the garden to conceal the rim of the basin.


Backyard water gardens

Stocking Your Water Garden

Plants —

Many water gardens will have basins with sloped sides and planting terraces so you can install a wide variety of plants at different depths.

Water gardens can include floating plants, submerged plants and edge plants. 

Floating plants shade the water, absorb dissolved nutrients, suppress algae and clean the water garden. Floating plants include water lettuce, water hyacinth and water lilies. Lotuses are a pretty option, too, even if they’re not technically a floating plant (they’re close enough for our purposes here) and are rather deep-water emergent plants with “blooms” that float on the surface of the water.

Submerged plants grow beneath the surface of the water, and are called oxygenators. Submerged plants provide a nice hiding place for fish, but some can be invasive and might be better grown in containers. Submerged plants include eelgrass, anacharis, cabomba, and water milfoil.

Edge plants can be grown on basin shelves placed up to 10 inches below the surface of the water or in the soil next to the water garden. Common shelf plants include water plantain, sedges, and cattails.

Fish —

Fish not only add beauty to your water garden, they eat mosquito larvae and some, like koi, also eat algae, keeping its growth in check.  If your pond is stocked with fish, especially koi, you should install a filtration system to clean and aerate the water. A good rule of thumb is to have no more than one fish per three square feet of surface area.

Common fish used in water gardens include:

Decorative Koi – Koi require highly oxygenated water, so you’d need a filter and pump if you stock your garden with koi. They must also be fed daily.

Comet Goldfish – these brightly-colored reddish-orange fish are popular additions to water gardens

Fantail Sarrassa Goldfish – these fish boast a double fan-shaped tail and red and white skins 


Most water garden maintenance depends on what type of water garden you use, but for the most popular in-ground variety, maintaining your water garden will average about two hours a week.

Maintenance includes:

    • Removing dead or dying plant matter. 
    • Cleaning out the pond liner at least once a year to remove waste and other debris that builds up on the bottom. 
    • Changing nearly half of the water every month to keep it fresh and clean.
    • Removing algae. One way to counteract algae is to include rooted plants in your water garden, which absorb nutrients that feed algae. If you want a lower- maintenance garden, use floating leaf plants to absorb the nutrients that feed algae and dye your garden water black to prevent light that encourages algae growth.


A small container water garden can cost $50 to $100 and a larger in-ground garden can cost thousands of dollars. A good rule of thumb is to figure that installation will cost roughly double the cost of the materials used for labor.

Some Points to Ponder

    • Experienced garden designers can review plans and make recommendations. You’ll need to understand flow rates and other terms. Find a contractor who specializes in water features, waterfalls, streams, and aquatic plants as a primary business.
    • Think about where you are going to put soil you excavated for the hole.
    • Choose right type of size of pump and filter.
    • If you are installing a water supply, get a pro.
    • Think of your water garden’s electrical needs, and make sure your circuit box can handle the additional load.
    • If you have small children, consider installing a fences around your water garden.
    • The safest edging is that which gradually gets deeper to prevent a rapid plunge into the water.

Your Turn…

Water gardens are perfect additions to backyards with enough space and for homeowners with the inclination to care for them. Have you thought of adding a water garden?

Photos: Unless captioned, photos include Water garden with lilies. Broadmoor Hotel, Colorado Springs, Colorado (October 2006). Photo by Peter Rimar