Going, going…

After three months of dry weather my New Pond is now nearly dry. What will happen next? What will the effect be on the pond? We really don't know: which is why I'm keen to let it dry out to see how the pond and its plants and animals fare.

It always seems one of the worst things that can happen to a pond: drying out.

But we’ve known for a long time that, out in the wild world, it’s not such a big disaster.

And more than 15 years ago we wrote an article in the excellent British Wildlife magazine called ‘New approaches to the management of ponds’ where we first highlighted the fact that drying out was nothing like as bad for pond wildlife as it can at first appear .

You can read that article here (scroll through to the section called ‘Drying out’ on p276 to see what we had to say on the subject back then).

And the reason it’s not so bad is that many shallow ponds naturally dry out during dry years, or if they are shallow enough, every year.

And many plants and animals that live in freshwater are perfectly happy with this arrangement – maybe as many as half of all species.

But what about in garden ponds? Well, the simple truth is we have absolutely no idea what will happen to the wildlife in the medium term in a garden pond that dries out in summer.

Probably there will be some short-term casualties. The sort of fish we keep in garden ponds will obviously not survive – although in more natural environments – say on a river floodplain – a pond that dries out only once in 5 or 10 years could still provide a valuable habitat for fish in all the intervening years. And some fish – eels spring to mind – could get away.

Things which can’t fly away, like tadpoles and newtpoles, snails, leeches and shrimps, are also destined to die. Though even here it’s not quite so simple: there are temporary pond specialist snails, like the Button Rams’s-horn, Anisus leucostoma, which live in temporary ponds and some leeches are amphibious too.

But most insects that can fly, or can recolonise by flying, like water beetles, dragonflies, mayflies, caddisflies, alderflies, water bugs, backswimmers, pond skaters – which between them make up most of the animals found in ponds – may be little affected in the medium term, as long as there is somewhere to recolonise from. And some tadpoles have already got away from the pond so the fact that a few will perish probably doesn’t matter all that much: the adults will be back next year.

And many water plants survive the summer drought period too. Even if the adult plants die, there may still be seeds or resting stages that survive the dry weather.

So I’m watching with interest what will happen to the New Pond as it is almost certain to dry out now – with just an inch of water left.

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5 Responses to “Going, going…”

  1. Diana Says:

    We have had a reprieve here in the north and the new pond is almost full again with the help of our new waterbutt. We are keeping one for the tomatoes and one for the pond. So I feel I can now proceed with planting. All that has colonised the pond so far are small beetles – there were some beetle larvae, not the diving beetle, but ones that dived very busily up and down. But have not seen them recently so perhaps they have pupated? We managed without topping up with tap water. But in the dry weather it has proved a great attraction for the garden birds.

  2. Sally Says:

    Our new pond is also suffering round the edges but we made it deep in the middle for our newts so there is still a lot of water there. It is a great success, full of insect life plus a frog and newts. We also have lots of damsel flies in many colours. We have waterbutts but none within reach of the pond. I have now bought a waterbutt tap which will take a hosepipe fitting and we hope to set up an emergency filling system for the 2 big ponds.

  3. Martin Says:

    Great to hear that the ponds are being allowed to dry out…how else are we to learn about the semi-natural process. I have left many a garden pond to dry out. The excitement of watching life come back is more exciting than watching the last world cup final. If you have not experienced a dry pond and are tempted to fill the pond with water, can I advise you to watch the drying process first, then you have added to your experiences. You can then re-assure those concerned that it is not disaster at all….far from it infact.

    Please also remember, what is around your pond is as important as what is in it. So make sure there are log piles of various sizes, stone piles and vaious clay, plastic and stone pipes in piles. These are great habitats. Ensure you grow shady plants and grasses. Cut grasses around the pond edge only twice a year, June and October, although you may want to leave the latter cutting to just once(June) in some areas.

    I have to say, this is one spectacular summer, especially for dragonflies and damselflies. There was so much food in my pond this year that the drangonflies emerged a year early! Cheers…happy ponding!

  4. Judith Says:

    I wish I could agree with Jeremy and Martin about allowing ponds to dry out completely, but for me the whole idea of constructing ponds in the garden was to provide a breeding ground for amphibians, and to attract new species so it does seem rather pointless to allow all the tadpoles and newtpoles to die out in a dry pond when it can be topped up with rainwater from the butt or if necessary tap water. My pond has all the species in the pond dip list, despite being constructed in the more ‘conventional’ way with a 60cm deep middle and plant rich mud shelves. The water is clear despite being topped up with tap water and so far this year – no blanket weed! Sally has a good idea for filling her ponds. I have a butt collecting water from 2 sloping roofs which then drains into the pond via a permanent hosepipe connection buried in the soil for 60ft up the garden. It may be scientifically interesting to watch a pond dry out, but I cannot do it. Does anyone else agree?

  5. pondolive Says:

    I think a really important feature of natural ponds that is lacking in garden ponds is a good layer of bottom mud (or perhaps sand or similar). Mud remains damp for a surprisingly long period and it’s incredible how many pond animals and plants have adaptations for surviving in mud. Many aquatic plants can regrow from roots, resting buds or seeds, and animals like waterfleas and moss animals have seed-like resting bodies. Many snails and leeches can survive in damp mud, as can Jeremy’s eel I suspect! I wonder if things like dragonfly larvae can too…? In fact I’d go so far as to say that – fish excepted – any pond animal that can’t fly can probably survive for at least short periods in mud. On the other hand, when dry I reckon a black pond liner with a thin layer of gravel is likely to prove a much more hostile environment for pond animals, because it will tend to heat up and dry out much more quickly, and because animals can’t burrow into it properly.

    Tristan

    Visit my blog at pondolive.wordpress.com

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