Building a pond — water as the heart of the garden

A Pond is a powerhouse in the permaculture garden. It stores water, evens out temperatures, hosts more life per square metre than any other element — and delivers you, free of charge, an army of Beneficials: dragonfly larvae, newts and frogs that devour mosquitoes, Slugs and Aphids. A body of water is the most effective invitation to nature you can extend.

The secret is the gradation

A living pond isn't one deep hole, it's a set of tiers. Each depth is its own habitat with its own plants:

• Marsh zone (0.0 in–3.9 in): the permanently wet edge. Marsh marigold, purple loosestrife, water mint. This is where amphibians get in and out.
• Shallow-water zone (3.9 in–15.7 in): the productive heart. Reed, bulrush, branched bur-reed — they filter the water and give dragonflies their nursery.
• Deep zone (from 31.5 in): the frost-free refuge. Animals overwinter here and the water stays liquid down below. Water lilies root here.

The minimum depth of 31.5 in (better 39.4 in) isn't optional: only that way does the pond not freeze through to the bottom in winter and not tip over so easily in summer. Shallow liner ponds heat up, go algal and die — depth is stability.

Choosing the site

• Partial shade — 4–6 hours of sun. Full southern sun makes the water go algal, full shade prevents plant growth.
• Not directly under deciduous trees — falling leaves over-fertilise the pond (leading to sludge).
• As level as possible, with a gently sloping side to the south — there the important marsh zone becomes broad and warm.
• A shallow exit zone (stones, gentle slope) is a must — otherwise hedgehogs and young animals drown.

Construction with pond liner

1. Dig out the profile: excavate the tiers directly along with it — wide shallow-water terraces (at least 11.8 in wide), then more steeply into the deep zone. No vertical walls, always sloped.
2. Clean the subsoil: remove stones and roots — anything that could pierce the liner.
3. Sand bed (1.2 in–2.0 in): spread the whole pit with moist sand — that protects the liner from below.
4. Protective fleece: a pond fleece (at least 300 g/m²) over the sand. Cushions against later settling.
5. Lay in the pond liner: lay EPDM rubber (durable, flexible, frost-proof) with few folds, press it neatly into the tiers. Leave a generous overhang at the edge.
6. Fill & arrange folds: flood slowly, pulling the liner along as you go. When full, secure the edge with stones or a capillary barrier (gravel) and trim the liner.
7. Plant it: aquatic plants in baskets with lean substrate (no Compost! — it over-fertilises), covered with gravel.

Water, algae & the balance

At the start every new pond goes green — that's normal. After a few weeks, once the plants take and microorganisms settle in, it clears by itself. You can help it along:

• Enough plants — they take the nutrients away from the algae. Rule of thumb: a third of the area planted.
• Keep nutrients low — no fertiliser, no leaf input, no fish in the natural pond (fish stir up, fertilise and eat the larvae).
• Top up with rainwater instead of tap water — tap water is often high in lime and nutrients.
• Patience — a young pond needs a season to come into balance. No chemicals.

Without a liner: the clay pond

Anyone with plenty of loamy/clay soil can also seal the pond the classic way — line the pit with a 7.9 in–11.8 in thick, well-tamped clay layer. More work, but completely plastic-free and extremely durable. On sandy soil this doesn't work — there's no way round a liner or a ready-made basin.

The pond in the garden system

Water draws life, and life keeps your beds healthy — a pond is supporting beneficials in practice. Combined with an insect hotel and flowering green manure a web emerges in which pests rarely gain the upper hand.

In the Garden Planner you can draw ponds as a circle or polygon shape; from that the planner calculates volume and a drought balance and places the water first, as the largest element on the map — everything else arranges itself around it.