What makes a pond a pond?

We all have a picture in our minds of what a pond is don’t we? For me it is the pond in the village I grew up in, a very traditional village pond with a duck house (which was constantly falling apart) and a selection of water lilies across the surface. But have you ever stopped to think what exactly makes a pond a pond?

As part of the Ice Age Ponds project we have been doing walking surveys to identify potential Ice Age ponds around Herefordshire and I have had my eyes opened to how far the definition of a pond can be stretched. So, we thought we would explore this variety of different ponds and how important they can be.

small, circular pool of water in grassy field — Pond (c) Rose Ellis

So is this a pond? It may be tiny, but it definitely fits the definition!

Pond definition

Firstly, how do we actually define a pond? The Freshwater Habitats trust includes this useful definition on their website:

“A pond can be defined as a body of water (normally fresh water, but occasionally brackish), which can vary in size between 1 square meter and 2 hectares (this is equivalent in size to about 2.5 football pitches), and which holds water for four months of the year or more.”

I don’t know about you, but this definition definitely pushed the boundaries of what I would have classed as a pond! So lets take a closer look at what it means.

We now have a clear size differentiation for when our pond is no longer a pond but is in fact a lake. But what about the other end of the size guide, 1 square metre? I have definitely found puddles bigger than this! Not to mention that many ponds can vary hugely in size.

Large expanse of water in a grassy field with trimmed winter hedge in the foreground — Pond (c) Will Watson

These two photos (left and below) show a pond that is fed by an aquifer and its size can vary drastically throughout the year.

Small areas of water with muddy surround in a grassy field with hedgerow and hills visible in distance — Pond (c) Giles King-Salter

This becomes even more interesting when you learn that the area only has to hold water for four months of the year. If we consider the winter months as likely to be the wettest then I am sure you will be able to think of puddles near you that could now be classed as a pond.

Waterlogged grassland with rushy grass and hedgerow in distance — The Sturts (c) Will Watson

This is a pond on The Sturts, a Herefordshire Wildlife Trust nature reserve. This pond dries out completely and is often only visible because of the wetland vegetation surrounding it

Temporary (ephemeral) ponds

We know that ponds provide a vital habitat for a lot of wildlife, two thirds of freshwater species are supported by ponds (Freshwater Habitats Trust), but what you may not know is that even temporary ponds can be vital to some species survival.

There are many pond loving species that only actually require a pond for a short period of their lifecycle. Did you know that great crested newts can spend four to five years away from a pond before finally returning there to breed once they are fully mature? Frogs and toads also only use ponds as a breeding ground and spend the majority of the year on land. But its not only amphibians who leave ponds once they are grown, water beetles and other invertebrates also only spend part of their life cycle in the pond water. For these species temporary ponds provide the perfect breeding ground, because the water is not there year around there are no fish in these ponds. A pond without fish is a pond with fewer predators and hence a safer breeding ground.

Pond in grassy landscape with a large tree on its left bank and a smaller tree on the right bank, winter. — The Round Pool, Moccas Park (c) Will Watson

The Round Pool at Moccas Park National Nature Reserve (left) dries out completely come the summer as you can see in the second picture (below). But while it holds water we have found smooth newts, a range of diving beetles and a large selection of other invertebrates in the water.

Indent in grassy field with a large tree in leaf to the left, a smaller tree to the right and other trees beyond — The Round Pool, Moccas (c) Robert Cook

As the pond begins to dry out the area where it was will often remain wet and boggy, sometimes all year around. This can provide a good feeding ground for birds, insects and other wildlife.

So just because a pond isn’t there all through the year doesn’t mean it isn’t valuable.

What makes a ‘good’ pond

Well this depends on what you want your pond to be good for. Ideally a pond could provide habitats for a wide range of species. Some good indicators of how healthy a pond is:

The range of vegetation – is there submerged vegetation (e.g. pondweed), emergent vegetation (e.g. bulrushes) and floating vegetation (e.g. floatgrass)?
Open water – are there areas of the pond free from vegetation?
How shaded is the pond – is there a mixture of shaded areas and areas that will get the full warmth of the sun?
What lives in the pond – is there a range of wildlife in the pond itself, species such as water mayfly nymphs are good indicators of a pond with less pollution. Species like water louse don’t require such good quality water to survive so large numbers of them can indicate a polluted pond.

A pond with a variety of vegetation, a mixture of shade and sun and healthy water quality is probably a ‘good’ pond.

Pond in winter surrounded with long grass and bushes — Pond (c) Will Watson

This pond has a good range of vegetation, and some small patches of open water as well. The trees to the left of the pond will provide some shaded areas but may need to be managed to stop them from overcrowding the pond.

Why not make your own pond?

Now you know how small a pond can be why not create your own in your garden? Ponds provide habitats for freshwater species, food and water for wildlife like birds and hedgehogs and can be great for your wellbeing too!

The great thing about ponds is that they can exist anywhere, one of our volunteers has even built a pond in her polytunnel and she gets tadpoles there every year.

Small pond lined with black plastic with plants growing in and around — Garden pond (c) Barbara Joss

A pond in a polytunnel (left) and this year’s tadpoles (below). The warmth of the polytunnel means that the frogspawn hatched earlier than it might otherwise have done and even at the end of March they were starting to become tiny froglets!