How deep does your pond need to be?

The Old Pond is not looking like a thing of beauty, but the wildlife is doing fine at the moment in just 5 cm of water

With the drought continuing, at least here in Abingdon, my Old Pond now has a maximum water depth of 5 cm in three separate basins.

I’m now starting on the third of my five rainwater butts keeping a bit of water in the pond.

It has to be said, it’s not looking great! And with all that duckweed……ugh.

So it was good timing that last week we did a detailed survey of the pond as part of student Emeline Favreau’s project with us, following up on some of the Abingdon ponds we surveyed in detail last year.

It’s been clear all along that my Old Pond is one of the better ponds in the Abingdon gardens as we might expect given its combination of clean water, shallow depths and pretty natural edges. But has the low water made any difference?

Well…the answer seems to be – not much.

We found all four species of dragonflies and damselflies which are breeding in the pond: so that’s plenty of Large Red damselflies, Broad-bodied Chasers (we saw c.20 larvae), a few Common Darter larvae and a couple of Brown Hawker larvae.

There are still mayflies, and we found caddis – though we haven’t identified the species yet – and it has the be remembered that the summer is not such a good time for finding caddis as many emerge quite early in the spring and may not have hatched a new generation yet.

There were Spotted Backswimmers (Notonecta maculata) and what will probably all turn out to be Common Pondskaters (Gerris lacustris), much the same as last year.

Last year we found 11 species of water beetles, and we’ve got at least 10 this time.

There are still plenty of Smooth Ram’s-horn snails – one of the ponds specialities – though we may not have any Whirlpool Ram’s-horns this time.

There is one more wetland plant species than last year with the arrival of Marsh Willowherb.

And there have been young frogs metamorphosing through the dry period.

We found one creature this year which wasn’t there last year, and that was a Horse Leech, which had colonised the pond in the intervening period.

All in all, the low water has made very little difference to the pond so far – with only two lesser water boatmen missing, perhaps because they really do need some open water over bare substrates.

It’ll be interesting to see how things go on over the rest of the summer and autumn.

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One Response to “How deep does your pond need to be?”

  1. Phil Agate Says:

    I think we can all get away with a lot more in the Summer than in the Winter. We can always add a little water to a pond from a butt or with a hose (hose pipe bans allowing) but I have to say I was a lot more worried during the last winter when ice depths were leaving only a few inches of water remaining.

    I am in West Sussex and it did actually rain here last night and this morning but not for long. However it is now school holidays, so I would expect a fair bit more of the old wet stuff for the next few weeks!!

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