DIY Backyard Pond: A Cheap Step-by-Step Build

The cheapest way to make a pond is a watertight container sunk into the ground or set on a patio, with a few plants and some rocks around the edge. A dug pond with a flexible liner costs a bit more and gives you a custom shape, but both are weekend projects you can do without a contractor.

Below is how to build a pond step by step: where to put it, how deep to go, how to fit the liner, and how to keep the water clear without spending much.

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Where should you put a backyard pond?

Pick the spot before you buy anything. Stand at the windows you use most and look out: a pond you can see from the kitchen or sofa gets enjoyed far more than one hidden behind the shed. Photograph the area morning, noon and late afternoon to see how much sun it gets.

A few practical rules help:

• Choose level ground, or ground you can level easily. Water exposes every slope.
• Keep it away from large trees. Falling leaves foul the water and roots make digging miserable.
• Aim for a mix of sun and shade. Too much shade limits plant growth, and a pond in full sun all day tends to get green quickly.
• Check where underground utilities run before you dig, and ask your local building department whether ponds need a permit or fencing where you live.

If you have a dog or small children, think about access too. A shallow entry shelf lets an animal that falls in climb out, and a ring of rocks or a low planting bed discourages wading. Check with your vet if you worry about what your dog drinks or swims in.

Can you just dig a hole and make a pond?

Not quite. A bare hole in most soils drains within days, and clay holds water only unreliably. You need something to hold the water: a rigid preformed basin, a flexible EPDM or similar pond liner, or a watertight container.

Whatever you choose, the digging rules are the same. Dig a bit wider and deeper than the basin, remove sharp stones and roots, and line the bottom with a layer of sand so nothing punctures the shell. I'd skip plastic landscape cloth around the pond. Penn State Extension notes that plastic or synthetic landscape cloth is not recommended on top of or under the soil because it can increase erosion and runoff. Sand or old carpet-free underlay alternatives such as a thick sand bed do the job better.

How deep should a small backyard pond be?

For a small decorative pond with plants, about 18-24 inches at the deepest point is plenty. That is enough for water lilies and a few marginal plants, and it keeps the digging manageable. If you plan to keep fish through a cold winter, the pond needs to be deeper than that, so research your climate first.

Build in levels instead of a single bowl:

1. A shallow shelf about 6-8 inches deep around part of the edge for marginal plants.
2. A middle level for potted plants.
3. The deepest zone in the center or at one end.

If wildlife is the goal, add a very shallow beach. Penn State Extension says birds will only use a bath with water no more than two to three inches deep, so a gently sloped stone shelf at that depth makes the pond useful to them.

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How to build a pond step by step

1. Mark the outline with a garden hose or rope, then look at it from the house and adjust.
2. Dig to the planned depth, forming the shelves as you go. Check level across the rim with a long board and a spirit level.
3. Remove stones and roots, then spread about an inch of sand across the bottom and up the sides.
4. Lay in the preformed basin, or drape the liner loosely across the hole with extra material on every side. Let it settle under its own weight. Do not stretch it tight.
5. Start filling slowly. As the water rises, smooth out folds and tuck the liner into the shelves.
6. Trim the excess liner, leaving at least 6-12 inches to anchor under the edge stones.

To work out liner size, add the pond's maximum depth twice to its length, and do the same for the width, then add about a foot of overlap on each side. Buying a little extra costs less than coming up short.

How to build a small garden pond from a container

A container pond is the lowest-effort route and works well on a patio, a balcony or a rental yard where you can't dig. A half whiskey barrel with a pond liner insert, a large glazed ceramic pot with no drainage hole, or a galvanized tub can all work.

• Seal or line any container that might leak, and make sure it is not treated with anything that can leach into the water.
• Raise the plants on bricks or upturned pots so they sit at the right depth.
• Check the weight. A full barrel is heavy, so on a balcony or deck confirm that the structure can carry it.
• Let tap water sit for a day or use a conditioner before adding anything alive.

For more ideas on dressing up a small water feature, see these cheap DIY pond decor ideas.

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Finish the edges and plant for clear water

Edges are where a pond goes from a hole with a liner to something that looks like it belongs. Overlap flat rocks over the liner edge, tuck gravel in the gaps, and let a few plants spill over the stones. Local stone is usually cheapest and looks the most natural. If you like rocky planting schemes, rock garden ideas carry over well here.

Plants do real work in a pond. Aim for a mix of types:

• Marginal plants on the shelf, such as irises or rushes.
• Submerged oxygenating plants, which compete with algae for nutrients.
• A few floating or lily-type plants to shade about half of the surface.

Group plants in drifts of one species rather than scattering single specimens. Master Gardener Deb Christopher of Westmoreland County makes the general point about groundcovers that "If disease or pest problems arise, the entire monoculture planting may be killed. Instead, consider planting drifts or groups of single species, providing a patchwork-quilt effect." The same idea of a few groups, not one big block, applies around a pond.

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How to make a natural pond and keep it clean

A natural pond relies on plants, a bit of shade, and a balance of life instead of a heavy filter. Skip fish at first, or keep the numbers low, since fish waste is the main driver of green water.

• Cover roughly half the surface with plant growth.
• Scoop out fallen leaves before they sink and rot.
• Top up with water in dry spells, but avoid big water changes.
• Add a small pump or solar fountain if you want moving water. It is optional, and a modest one is enough.

Expect the water to turn green for a few weeks after setup. This usually settles as plants establish. Keep pet food, fertilizer and lawn chemicals away from the pond, and if a dog drinks from it regularly, ask your vet whether that is a concern.

If you later want fish, read up on building a koi pond cheaply, because koi need far more depth, volume and filtration than a decorative pond.

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Cheap ways to save money

• Use a container you already own, or a secondhand one.
• Collect local stone and ask neighbors who are clearing a garden.
• Divide plants from friends' ponds instead of buying them.
• Skip the pump on a first pond and add one later if you want it.

As an architect, I'd spend the money on the liner and the leveling, and be thrifty about everything else. A leak or a tilted rim is the one mistake you can't hide with decor.

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