The new pond, finished on 26 April 2009: now I'm just waiting for the rain to finish filling it
This is the full story, in pictures, of the making of my new wildlife garden pond.
I’ve tried to bring together a design which takes account of the many myths that exist about ponds and which have come to dominate garden pond design.
What makes a good wildlife pond is:
- really clean water: this is the most important thing you can do for a wildlife pond.
- plenty of shallow areas: and shallow means less than 5 cm.
- edges as natural as possible: in a garden in practice this means grassy, very gently shelving, and gently varying in depth.
Most advice about garden ponds barely mentions these things. The reason: almost nothing is known about what really makes garden ponds tick. So writers, who abhor an intellectual vacuum, simply make stuff up! Amazingly.
The advice here is based on Pond Conservation’s work on ponds out in the countryside – but even we don’t yet know much about real garden ponds. But we’re learning fast, and the advice below is putting what we do know into practice.
UPDATE: As the pond develops I’ll also be trying to make it look as attractive as possible as well.
Anyway, back to the beginning: the 1st of March 2009 to be exact.
The first cut. I marked the site out with a rope. You can use a hosepipe, string between sticks, bamboo canes – whatever suits you.
For wildlife, the pond shape is less important than the depth (you need lots of shallow water) and the how clean the water is, and what the edges are like.
So ‘natural or ‘formal’: it depends on what looks good in your garden.
Remove the turves: you won’t be needing them again. Don’t put them in the pond! They will almost certainly add a massive blast of polluting nutrients to the water which will plague you for the rest of the pond’s life.
It doesn’t matter when you start or when you finish. I started in March because I had the time then – too late for breeding frogs this year but in time for the main period of warm weather when all kinds of bugs, beetles, mayflies, dragonflies and all the other things are flying about to colonise the pond.
I did a couple of hours digging each time.
By the 11th April I had all the turves stripped off. This took me about 6 hours all together – its slower if you don’t do it all at once. Probably I could have got this far in a long afternoon.
I was fairly confident that the site was more or less level – now it was time to check more carefully.
I needed a piece of wood more than 3 m long to go right across the pond. I didn’t have one at home so had to buy a piece from the local timber merchants for a fiver. I expect you could scrounge something like this for free.
With the spirit level laid on the wood, I could see that the pond was a little bit higher at the back, the side away from the camera.
It wasn’t too much but did mean a bit of fine tuning was needed at the end.
The bubble should be between the two lines
Its very easy to dig a wildlife pond too deep and end up with one of those things that looks a like a miniature version of a giant open cast mine.
A wildlife pond should have lots of shallow water – mine is roughly 50% shallows, and the deep area is not more than 30 cm.
The standard advice that you need to dig down to 50 cm or 60 cm of whatever the writer thinks applies only to fish ponds. The reason you’re told to do this – the pond might freeze solid – might apply in northern Canada, but is simple nonsense in England. The other reason – that oxygen may run out – is probably true sometimes but is not a cast iron rule.
Those of you who read the blog will know that in my first shallow pond oxygen levels rose during the ice cover this winter to double the normal value.
The other problem with digging down this deep in a small pond is that you end up with very steep, or vertical, edges. I’ve managed to get away with having only one ‘cliff’, between the shallow basin and the deep area.
The maximum depth is not much more than 1 spade deep
Update 2 May 2009. Just saw this comment on a wildlife pond making website:
‘To assist with water clarity, make your pond as big as possible and avoid a deeply shaded site‘.
There’s no reason to think that either the size or the amount of shade will have anything to do with how clear the water is.
In fact, shaded ponds ae more likely to be clear (less light for algal growth); size really makes no difference.
Anyway, getting back to story, at this point I realised I had a big problem with the edges.
Just in the simple act of removing the turves I’d created a massive steep cliff right at the edge of the pond: the place I was trying to get the gentlest slope.
This happened because its very difficult to dig a turf out that isn’t this 4″ (10 cm) deep because its where the grass roots down to.
There are probably a variety of solutions to this problem.
I chose to raise the turf, remove roughly half the soil from each turf making it half the thickness, and place the spare soil in from the of the turf so making the slope from pond to grass a bit gentler. I don’t think its the ideal solution but it was fairly quick to do.
Now the pond bottom will be at the same level as the bottom of the turf at the edge of the pond.
But the real way to get shallow water in a small pond is have shallow basins.
So this is the final shape: in large parts of the pond, it hardly looks as though I’ve done any digging at all. This is the right depth for pond wildlife.
Tadpoles love shallows: its where they spend a lot of time in my first pond.
Here are my taddies congregating in the shallow warm water they love. This is right in the middle of my first pond: normally the deepest area, in my pond its the exact opposite way round. The middle of the pond is the shallowest area, so shallow it will dry out in the warmer weather. But now its great for the baby frogs, and by the time it dries, they'll probably have grown up and left the pond
Almost all other pond wildlife is happiest in very shallow water as well.
Most garden ponds are too deep for their area: if you want a half metre deep pond, or deeper, it needs to be much bigger or you end up with very steep sides.
The really final shape with turves cut and arranged to cover the liner
The really striking thing about the final shape is just how shallow the pond is: I’m pretty pleased with this, although there’s room for improvement around the edges.
Now the lining: I opted to buy the underlay just for speed – I didn’t have any old carpet around so simply put down a double thick layer of the underlay on sale at the garden centre.
I did remove the stones fairly carefully, but I didn’t bother with sand.
As the total bill for liner and underlay was £134, and as I will have hours of pleasure from the pond for nothing apart from this, I didn’t mind the expense. The liner itself was £90.30. But the resourceful could do it for less.
This is the same approach as I took on the first pond (except there I had a left over roll of underlay I could use from the previous owners of the house).
And then suddenly we’re nearly done: put the liner over the top and add some water to hold it down.
Notice – no hoses. My tapwater is not fit to use in a pond – full of nutrients. In some parts of the country (in the north, for example) its OK where its come off the moors. Down south, its mostly not fit to use in a pond. In most parts of England you can check on the water companies website whether your drinking water is fit to go in a pond – in about half the country it isn’t.
From here on in we have a pond!
Now you begin to see the two halves of the pond.
Now it’s just a case of finishing putting the turves in place, and trimming the liner and underlay.
I didn’t quite have enough water in my water butts to fill the pond completely so now we need to pray for rain – luckily it came the next day.
Everything trimmed up, and the turves all in place. There’s even the first leaves falling in the pond: leaves are a great source of food, shelter and building materials for pond animals.
And finally:
Two months almost to the day (this picture was taken on 27 April 2009) the pond is finished and ready for wildlife to find it.
Its still not quite full: the next day the rain came.
What’s next?
Well, we will add some plants to this pond: local, native, wild sourced plants (only collected from landowners who’ve given permission).
We won’t add ‘pond sludge’: the pond doesn’t need to be ‘started’. We’ve started it simply by making the hole and filling it with clean water, and anyway that sludge is quite likely a source of nutrients from someone elses pond that we don’t need.
We don’t want soil, or turves or fish food or any other of the pollution sources that commonly find their way into ponds. We will have more than enough just coming down in the rain (rain itself is slightly polluted these days).
We will put some clean children’s play sand on the bottom to make the pond a little more natural looking. This is chemically inert so no pollution problems, provided its clean.
And the wildlife? Well that started to arrive on day 1 with little flies laying their eggs, and on day 2 the first water beetles flew in.
May 2, 2009 at 9:56 am |
[...] The Garden Pond Blog Everything about making garden ponds for wildlife (and looking after them, too) « Pond Story: making a new clean water wildlife pond [...]
May 2, 2009 at 11:46 am |
[...] 2nd May 2009: See the whole process fro mstart to finish of making a new clean water wildlife pond at Pond [...]
May 8, 2009 at 7:56 am |
[...] A better shape is shown in the photo sequence for my new pond. [...]
July 27, 2009 at 9:47 pm |
Just came across your blog – very useful as I have just started to dig a pond and was wondering about depth etc. Agree with you re depth, we have a tiny pond and after 2 weeks freeze only an inch or so frozen on top, but of course the deeper it is the warmer it will be at the bottom, maybe the frogs need +3C or something i.e more than just not freezing solid.
Also, I do not quite see what is so wrong with steep edges within the pond. So long as you have shallow areas & hedgehog-friendly margins, why are underwater cliffs so bad for wildlife?
However, what I really wanted to ask you about was the margins. I see you brought the liner up and out and then topped it round the edge with turves. But will these not die in dry weather? they have no depth of soil under them and will be like grass which creeps out over the pavement – fine in damp weather and the first casualties in dry spells?
February 19, 2010 at 11:10 pm |
What an excellent blog and an excellent website. Could you give us some information about suggested pond area though? Everything I’ve found pretty much says do what you want – but my garden is only about 11×3.5 metres, not including the patio outside the house and the shed at the far end. Obviously I don’t want the pond to take up the whole width of the garden or to otherwise dominate it. What’s the absolute minimum area – particularly the minimum width – that I could get away with to have a pond which is capable of supporting wildlife and won’t evaporate?
Also, I have a small apple tree by the shed at the end of the garden. If it weren’t for the tree, I’d say that the end would be the least intrusive place for the pond. But I’m concerned about roots piercing the pond lining, and I’m unsure how much the tree, which would be WNW of the pond, would block the available light. How much of an issue is this?
February 20, 2010 at 1:28 pm |
Hi Kieran – I’d say that 1m would be about the minimum; not because there’s anything magic about 1m but because any narrower and it would be hard to have anything except steep/vertical edges both sides.
But maybe a better bet would be to have say 2 x 1 m or 3 x 1 m with each square metre a different depth – say one with just 5-10cm depth, one 15 cm deep and one 25 cm max. Make them a bit uneven so they’re not all the same depth all the way through.
I’ve never seen a pond like this except in some experiments done to test pesticides but I think it could work.
In the south of the UK all ponds this size could dry out in a dry summer. To stop it drying out completely it would be good to connect it to the roof water, or a water butt filled from the roof.
Of course temporary ponds are a good, and special habitat, but I think if you’ve only got room for one pond they’re probably a bit difficult. There are no good ones in gardens so far.
As for the shade, my first pond has virtually no direct sunlight except for about a quarter of the pond in the middle of summer. The rest of the year it is shaded by 10 – 20 foot trees and a hedge. And that’s no problem.
I would try to avoid putting it right under the tree: I’m no tree specialist but it might not do the tree too much good if you have to chop a lot of it’s root, and they might be a problem for the liner (though I do wonder how often roots really penetrate intact liners).
Jeremy
February 20, 2010 at 2:16 pm
Hi Jeremy,
Thanks for that, it’s really useful
. I’m sure I’d be able to make the pond at least 1.5 x 3m so that’s just right.
I’ll have to think about your suggestion of connecting the pond directly to the water but/water drainage, but it brings up the question of flow control. Direct connection to the water drainage risks, I fear, either flooding the pond at times while not having enough water stored for the dry months. I imagine a direct connection to the water butt would require manual flow regulation with a tap? I don’t think it could be easily made to self-regulate.
Then there’s running piping along the length of the garden which, although probably not hard, is going to make the project considerably more complicated and expensive. I wonder also how much water the shed roof might provide.
As for the tree, I’ll have to look at how far its roots have grown. I suspect you’re right about the roots not finding a properly-sealed pond lining but I imagine the risk is even lower with a fibreglass pond mould. Unfortunately I’ve not been able to find any that match your design specs – I wonder whether there’s a niche in the market for selling shallow, gently-sloping fibreglass ponds!
Going back to water butts etc, how much of a problem do you get with mosquitos laying larva in yours? I have a burning hatred of mosquitos and don’t want to do anything to encourage them. I’ve been reassured by the kind people at Pond Conservation Advice that this shouldn’t be too much of a problem with a healthy pond that’s supporting enough predators to eat the things, but I remember as a child trying to chase the larvae in my parents’ water butt and I want to avoid the same thing happening. I wonder if the unit could be sealed, with some sort of one-way valve in the gutter pipe, to prevent the nasty things getting in to lay eggs?
February 20, 2010 at 3:21 pm |
Hi Kieran – yes i remember the discussion about mosquitos!
But I’d be surprised if you had much trouble with them even with a water butt (or butts).
There are larvae in ours butts but we rarely / never get bitten and the ones in the butts could anyway be a species that don’t bite people (I haven’t actually checked which ones they are). But some kind of seal might work.
In fact in our garden when we do get bitten its actually blackflies which come from a stream about 250 m away. I’ve never noticed being bitten by a mosquito out of doors.
To keep things simple in terms of pipes you can just store the roof water in a butt and not worry about connecting directly to the pond. A surprisingly large amount of water will simply fall into the pond from the sky and you can probably top up with a few bucket fulls of water whenever you feel its getting too low.
I did have my first pond connected to a water butt directly but after while it was clear I didn’t really need to worry too much about it – it stayed topped up as much as I wanted – in fact the only time we’ve topped it up in three years was for the TV! When they came to film it was a bit low looking – so we added water then, but otherwise it has remained amazingly full – perhaps becaue it is realtively shaded.
And you don’t need to keep it brimful all the time – going down to half depth in the summer isn’t likely to be a problem for wildlife – though it might not look great.
The most important thing is to make sure you stick to rainwater (assuming you’re in apart of the ocuntry where tap water is nutrient enriched).
Jeremy
March 2, 2010 at 5:18 pm |
The problem with shallow ponds is that in summer they dry out very quickly so in a reasonable sized pond you will quickly use up all your water from water butts. if you go on holiday for a week you can come back and find the pond a desert and all the wildlife dead or gone. This is particularly true if it has marginal plants. I will make my shallows a foot deep and put in some rocks to allow things to get in and out.
March 3, 2010 at 12:44 pm |
Hi David
In our old pond – which has a maximum depth of about 25-30 cm, we have added water only once since spring 2007. And we only did that because we had TV coming – that was last summer and the pond was still half full but we wanted it to look a bit nicer for the cameras!
Admitedly we have had wetter springs than usual but I think you would be very unlucky to have a pond dry out completely in one or even two weeks, if you started from fairly full.
Another problem is that people are commonly advised to put ponds in full sun where evaporation will obviously be greater. Our old pond is shadier and I think it goes down less quickly than our new pond, which is in full sun, because of this.
Having said that, our new pond which we made last spring did not dry out in the summer, which was pretty dry (see the Centre for Ecology and Hydrology’s monthly summaries of rainfall and water resources here: http://www.nerc-wallingford.ac.uk/ih/nrfa/monthly_summaries/archive.html).
Our new pond is also very shallow.
It’s also worth bearing in mind how many freshater plants and animals are adapted to periods of drying out – not fish, of course, but many things can comfortably survive low water levels and even complete drying out, by hiding away under logs, vegetation and so on. Other creatures can happily move on, and come back another time.
One thing that is still difficult – working out how to make the damp conditions typical of more natural ponds when you’re using a liner – I don’t think we’ve got the designs right for that yet as you probably need decaying wood, mats of grasses and so on to retain moist spots.
March 4, 2010 at 10:55 pm
An interesting point about decaying things and grasses etc. You say in your blog that the pond doesn’t need to be “started”. I take it the grasses would root in the sand you said you’d be putting in – have you done this now? Have you/did you cover the whole of the bottom of the pond with it? How thick? Has it stayed where you put it or has some of it just moved over to the lowest point in the pond? How effective was the sand?
I’m hoping to make a start on my pond next year – to be honest I’ve only just found out that I’m definitely returning to the UK at the end of this year – so I’ll let you know how it goes
.
June 3, 2010 at 10:19 am |
Hi
At long last I have posted you a rough drawing today of the ponds I had in mind, hopefully you can give me some ideas. My major problem, and no one else seems to have mentioned this, is that there is alot of cats coming into my garden, so I want to try and protect the wildlife as much as possible from the cats, any ideas? Plus what can I put into the shallow pond to hide the lining, if not pebbles/stones and what kind of earth/compost can I put in the bottom so that I can put the plants in directly?
All the best
Perry
June 6, 2010 at 10:31 am |
I would love to have wildlife pond but my garden is in full sun all day. There are no shaded areas. Would this be a problem?
June 6, 2010 at 10:56 am |
Hi Liz
No – it’s not a problem. In fact, the traditional advice is that ponds must be in full sun and it’s this traditional blanket advice that I’ve been disagreeing with.
Out in the wild there are ponds in everything from full sun to deep shade – and given the right management all can be good wildlife habitats (though in deep shade you’re probably not going to get your traditional lilies to grow).
Perhaps the most important thing is to make sure that you have enough clean water to last the summer – so you can do a bit of topping up to stop the pond drying our completely because the biggest problem will probably be the rate of evaporation – which is quite a bit quicker in the full sun. So work out where you’re going to get a good supply (and store) of rainwater first – I expect you’ve got a roof and this will provide all the water you’ll need if you can store it up over winter and then catch the summer downpours as well.
We’re still learning what the real issues are in full sun ponds: high temperatures may be one (we think the water temperature in our ‘sunny’ pond approached the lethal limit for our tadpoles in the recent warm weather, and it looks like it killed some of our water slaters too – and bigger swings in dissolved oxygen might be an issue as well.
But these are the details that we’re all still learning: fundamentally there’s no difficulty.
Jeremy
June 6, 2010 at 11:13 am |
Hi Jeremy, thanks for quick reply and so pleased that having no shade isn’t a problem. I had imagined that too much sun would mean pond covered in algae very quickly. We’ve just moved house and the back yard we’ve got hasn’t been a real garden for years. Have just finished clearing it and hadn’t really any concrete idea of how I wanted garded to go so have now decided to dig a pond and take it from there. As I’m away from home till beginning of August have covered garden over with membrane to keep weeds down. Will dig out pond when I get back home and I’m sure Scottish rain will fill it in no time. Will let you know how I get on. Very glad to have found your site. Thanks. Liz
June 6, 2010 at 11:36 am |
Hi Liz
Over-abundant algae is a sign of nutrient pollution – in gardens, usually from tapwater.
The sun doesn’t really have much to do with it – even though that’s what all the books say. It’s the nutrients – just think about all those Scottish lochs – out in the full sun, but barely a trace of filamentous algae – unless they’re polluted.
Jeremy
June 10, 2010 at 8:23 am |
Hi Jeremy
Yes please, any suggestions would be appreciated, thanks.
Perry
June 29, 2010 at 5:32 pm |
Hello Jeremy. I have just come across your very informative blog and I have a question for you. I created my pond about 5 weeks ago. It looks a lot like yours in size and shape and depth. I think it’s about maximum 30-40 cm at its deepest parts with shallow sloping sides. I filled it with rain water (we have an underground rainwater tank). I put in a layer of river sand. I plopped a few plants from the garden centre around the edges with no extra soil and they have rooted into the sand. I buried the liner around the edges and backfilled with subsoil to make boggy areas, taking care to ensure there no soil would run into the water (well maybe a tiny bit). Last week someone gave me some lillies from their pond which I submerged in the middle adding a bit of special pond compost. They are taking off well.
About 3 weeks ago, I fished some tadpoles from a local pond and put them in. They disappeared under the roots of a big iris and some rocks and logs. I did see one small frog two days ago swimming across the other side. All seems to be going very well: swallows and swifts are dipping and feeding over the pond, bees set up home in our chimney Saturday and they are constantly drinking at the pond, sighted a blue dragonfly, wasps drink regularly, and there are masses of birds having a ball.
We live north of Paris and we have been having some very hot weather, and the pond is in full sun so I have been concerned about the temperature of the water. It’ll be a while before the surrounding plants provide any shade.
When I put in the tadpoles in, I put in some algae for them to feed on. But now the pond is overwhelmed with the stuff. I go daily with a stick and twist it around picking up the algae like some green candy floss, but the next day there is just as much again. Is this algae harmful to the other plants (it seems to cling around their roots), or harmful to any other wildlife? Is it the hot temperature of the water that makes it proliferate? What can I do to regulate the quantity of algae? Would water snails help? I’ve also heard of barley straw…..
Sorry to be so long-winded but I wanted you to have the whole picture. I would appreciate any help you can give me. Thank you very much.
June 30, 2010 at 1:32 pm |
Green Algae
There is a lot written about Green Algae, so read websites etc for information…However….The most important ingredient to deal with algae is patience and trust. I have had it in all ponds created from new for the last 25+ years and I expect to see it, but do not despair!
You can pull it out with a stick or rake but I have 100 percent success by leaving the pond alone, no chemicals, no pulling out, no nothing. Just leave alone, it may increase but eventually it dies back of its own accord, goes brown, sinks to the bottom and decomposes as an aquatic soil at the bottom of the pond. Yes it does temporarily imbalance the oxygen levels in the pond, it does look unsightly for a time, but trust in being patient. Least interferience, equals best long term result. Barley straw is only for the pea green water problems.
It does help to have a deep water area in the pond, say 80- 120cm’s, to help prevent drying out, and maintain oxygen levels, but it is perfectly acceptable for ponds to be seasonal and dry out too. Hope this helps. Apologies to Jeremy to whom the query was targetted…didn’t want to interfere!
June 30, 2010 at 1:46 pm |
Hi Martin – Don’t worry – I’m very pleased to receive your comments.
Jeremy
June 30, 2010 at 5:35 pm |
Thank you, Martin.
Leave it alone, huh? Sounds like my kind of gardening!
July 18, 2010 at 9:30 am |
Have been building a small wildlife pond in my garden..roughly 2m x 1.5m. Read lots of info on the web, but this blog was really helpful in designing it, ie I have plenty of shallow areas, and max depth is no more than about 45cm. Have built trenches all around the edges, to prevent run off where I shall plant waterside flowers and grasses seed, and there will be a small bog garden about a foot from the pond.
Filled it yesterday with tap water. I know that’s not the best but I really can’t wait for the rain, living in south east London. But I’ve just bought a water butt which I’ll be able to use in future in topping up.
So far just chucked in little amounts of hornwort, starwort and frog’s bit bought from,
http://www.naturescape.co.uk/ (all their stuff has 100% British provenance)
I have a couple of water sedges I’ll put in it which I’d grown in my sunken aquarium for a couple of years, obtained from the local London Wildlife Trust pond. There’ll be planted in London clay/sand in baskets which I got from digging 2foot down in another part of the garden.
Within 4 hours off filling it yesterday, a pond skater had turned up. Not bad for a small garden pond in Peckham.
Shall write a fuller account of the whole project, which I’ll link to here.
Thanks Jeremy, your blog was really useful in planning it, even though I’ve used tap water initially. I know its not ideal but I don’t feel able to do absolutely everything according to nature, and there’ll certainly be no run-off from rest of garden because of the trenches I’ve dug all around.
July 18, 2010 at 10:36 am |
Hi GiddyGedy
It’ll be really interesting to hear how you get on. Do keep me posted!
Jeremy
July 27, 2010 at 10:51 pm |
Hi Jeremy
Very interesting blogs here – I am in the process of overseeing my friend’s new pond. I had two previous very successful ponds in Essex. Now live in south of Ireland in Co Cork. I used builder’s dpm for both previous ponds and as long as it isnt exposed to light, there were no problems at all. We had newts, frogs and toads as well as all the flying insects attracted to the oasis. I was very upset when my former next door neighbour told me the people who bought my house had filled in the pond!! I am going to make a pond in my own garden this year as there are none in the vicinity – a slow flowing river is a stone’s throw from my garden and I miss frogs and news and watching the birds taking a bath in the shallows.
July 27, 2010 at 11:03 pm |
Hi Mary – I’ll be interested to hear how you get on. If there’s any advice I can give, let me know. Jeremy