Lots of good advice already. It should be 3' deep at least; the water should not freeze solidly or you will kill all the invertebrates. Too shallow and it will freeze to the bottom.See original post
This is bad advice. Even shallow ponds in most of the UK are unlikely to get more than an inch or two of ice on top (at most), and are not going to freeze right down to the bottom. This amount of ice is normal and shouldn't affect the pondlife - you can often see water boatmen etc swimming about under the ice.
3' deep for a small garden pond is far too much. A maximum depth of 12"-15" is perfectly adequate - perhaps a bit more if you want to grow plants in baskets although personally I prefer them to be rooted in the sediment which looks much more natural.
Better to have a fairly gently sloping or stepped profile than a pond with a deep pit in the middle. The deep section won't benefit wildlife and will just act as a sump to accumulate a large quantity of leaves and anaerobic sludge which will eventually need to be cleaned out.
With a small pond it might be better to have an asymmetric profile with the deepest point near one edge so that one edge is steep (perhaps with a narrow shelf for a fringe of marginal plants) and the other can be more gently sloping, rather than having all the sides sloping down to the middle.
Good quality play sand makes quite a nice stable and low nutrient planting medium for shallow marginal areas and helps to protect the liner. Avoid builder's sand. and soil. If you're planning to plant straight into the bottom you don't need the planting areas too deep - most plants will be happy in just a few inches of water. Sand/sediment will slip off if the slope is too much, so generally better to have a series of level steps/terraces rather than a continuous slope.
Take care to make the edges of the pond level all the way round - a long spirit level can be useful.
Lots of good advice already. It should be 3' deep at least; the water should not freeze solidly or you will kill all the invertebrates. Too shallow and it will freeze to the bottom.See original post
This is bad advice. Even shallow ponds in most of the UK are unlikely to get more than an inch or two of ice on top (at most), and are not going to freeze right down to the bottom. This amount of ice is normal and shouldn't affect the pondlife - you can often see water boatmen etc swimming about under the ice.
3' deep for a small garden pond is far too much. A maximum depth of 12"-15" is perfectly adequate -
I disagree Ono. I think your 12-15 " is bad advice. Not enough IMO. We do have some cold winters in this country. I do not know where the OP lives but it is routine in many parts of the UK to get ponds freezing much more than an inch or two as you state with two feet not uncommon in a really cold winter. Ponds do silt up as anyone who has one knows and 3' can be reduced to 2 in a few years. When I said it should be 3' deep, I of course mean at it's deepest so the invertebrates have somewhere to go when there is a thick layer of ice.
Based in Sussex, I garden to encourage as many birds to my garden as possible.
Even in this ongoing sub zero environment it is unlikely that ponds, even shallow ones, will freeze solid. In this country it’s rarely cold enough for more than 2 or 3 inches of ice to form on our garden ponds, so only the very shallowest ponds, or small container ponds, can freeze completely solid. As long as your pond creatures have undergrowth to nestle in and a good oxygen supply they should be fine.
I disagree Ono. I think your 12-15 " is bad advice. Not enough IMO. We do have some cold winters in this country. I do not know where the OP lives but it is routine in many parts of the UK to get ponds freezing much more than an inch or two as you state with two feet not uncommon in a really cold winter.
I have two lined ponds here (Herefordshire) - one about 20-25 sq m which is about 1' at deepest, and one about 50 sq m which is about 14"-15" at deepest (and mostly much less than that). Even in the cold winters we had a few years ago the ice didn't get very thick on either - certainly not anywhere near freezing solid although the surface was covered. I can't speak for upland or northern areas, but in the lowland parts of Britain where most people live 2' of ice on a pond is simply not realistic. Apparently ice 8" thick is enough to support a small car - how often do you see a frozen pond you'd be happy to drive over?
Ponds do silt up as anyone who has one knows and 3' can be reduced to 2 in a few years. When I said it should be 3' deep, I of course mean at it's deepest so the invertebrates have somewhere to go when there is a thick layer of ice.
I think it's easier to regularly maintain a shallow pond than to let it silt up for years and then have a massive job on your hands. A thick layer of sediment can also potentially exacerbate the effects of freezing by depleting oxygen levels and/or releasing poisonous gases.
I went to a job once where the client had a problem with the water supply in his offices. We found the water tank in the roof was completely frozen solid - 5 feet deep, 8 foot square. Granted, a pond has the benefit of the earth around it, but on the other hand the tank is not exposed to a cold sky radiant effect.
That was in Plymouth, so definitely not North.
It was minus 16 degrees here in 2010. I'm in Devon, so still not North.
Don't believe any builders that tell you rain always falls downwards either.
None of this has any bearing on how deep your pond should be, of course. But it does get really cold in the UK, even in towns now and then.
Just sayin'
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first”
I thank you all so much for all your comments and input. There is lots there for me to digest and take away. You've all given me plenty of food for thought. Watch this - work is a good bit underway now and hopefully I will have made much more progress by the weekend.
I've had ponds of all sizes and shapes over the years, and they will freeze depending on the severity of the winter and the duration of the sub zero temps. However, it really does depend on where the pond is, what's round it in terms of planting etc for protection, and where you are in the country. None of mine have ever frozen by more than 6 inches. Two of them have had fish in them. One was very deep in the middle and had a natural, constantly moving water source at one end, so that bit was free of ice but the rest froze quite extensively. The other pond was a 'conventional' sized garden pond of about 18"/ 21" at the deepest point. I'm quite far north, and once ice forms on water, it stays for quite a long time.
I use a piece of polystyrene which has an indentation on the underside. It's tied to the surrounds of the pond with string, wire or similar, and that keeps a space unfrozen.
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
Posts
This is bad advice. Even shallow ponds in most of the UK are unlikely to get more than an inch or two of ice on top (at most), and are not going to freeze right down to the bottom. This amount of ice is normal and shouldn't affect the pondlife - you can often see water boatmen etc swimming about under the ice.
3' deep for a small garden pond is far too much. A maximum depth of 12"-15" is perfectly adequate - perhaps a bit more if you want to grow plants in baskets although personally I prefer them to be rooted in the sediment which looks much more natural.
Better to have a fairly gently sloping or stepped profile than a pond with a deep pit in the middle. The deep section won't benefit wildlife and will just act as a sump to accumulate a large quantity of leaves and anaerobic sludge which will eventually need to be cleaned out.
With a small pond it might be better to have an asymmetric profile with the deepest point near one edge so that one edge is steep (perhaps with a narrow shelf for a fringe of marginal plants) and the other can be more gently sloping, rather than having all the sides sloping down to the middle.
Good quality play sand makes quite a nice stable and low nutrient planting medium for shallow marginal areas and helps to protect the liner. Avoid builder's sand. and soil. If you're planning to plant straight into the bottom you don't need the planting areas too deep - most plants will be happy in just a few inches of water. Sand/sediment will slip off if the slope is too much, so generally better to have a series of level steps/terraces rather than a continuous slope.
Take care to make the edges of the pond level all the way round - a long spirit level can be useful.
I disagree Ono. I think your 12-15 " is bad advice. Not enough IMO. We do have some cold winters in this country. I do not know where the OP lives but it is routine in many parts of the UK to get ponds freezing much more than an inch or two as you state with two feet not uncommon in a really cold winter. Ponds do silt up as anyone who has one knows and 3' can be reduced to 2 in a few years. When I said it should be 3' deep, I of course mean at it's deepest so the invertebrates have somewhere to go when there is a thick layer of ice.
Article from fresh water habitat trust
Even in this ongoing sub zero environment it is unlikely that ponds, even shallow ones, will freeze solid. In this country it’s rarely cold enough for more than 2 or 3 inches of ice to form on our garden ponds, so only the very shallowest ponds, or small container ponds, can freeze completely solid. As long as your pond creatures have undergrowth to nestle in and a good oxygen supply they should be fine.
I disagree Ono. I think your 12-15 " is bad advice. Not enough IMO. We do have some cold winters in this country. I do not know where the OP lives but it is routine in many parts of the UK to get ponds freezing much more than an inch or two as you state with two feet not uncommon in a really cold winter.
See original post
I have two lined ponds here (Herefordshire) - one about 20-25 sq m which is about 1' at deepest, and one about 50 sq m which is about 14"-15" at deepest (and mostly much less than that). Even in the cold winters we had a few years ago the ice didn't get very thick on either - certainly not anywhere near freezing solid although the surface was covered. I can't speak for upland or northern areas, but in the lowland parts of Britain where most people live 2' of ice on a pond is simply not realistic. Apparently ice 8" thick is enough to support a small car - how often do you see a frozen pond you'd be happy to drive over?
Ponds do silt up as anyone who has one knows and 3' can be reduced to 2 in a few years. When I said it should be 3' deep, I of course mean at it's deepest so the invertebrates have somewhere to go when there is a thick layer of ice.
See original post
I think it's easier to regularly maintain a shallow pond than to let it silt up for years and then have a massive job on your hands. A thick layer of sediment can also potentially exacerbate the effects of freezing by depleting oxygen levels and/or releasing poisonous gases.
Last edited: 04 October 2016 16:38:01
If the poster wishes to put fish in the pond then 3 feet is the minimum I think. Different if it is only going to be a wildlife pond.
I went to a job once where the client had a problem with the water supply in his offices. We found the water tank in the roof was completely frozen solid - 5 feet deep, 8 foot square. Granted, a pond has the benefit of the earth around it, but on the other hand the tank is not exposed to a cold sky radiant effect.
That was in Plymouth, so definitely not North.
It was minus 16 degrees here in 2010. I'm in Devon, so still not North.
Don't believe any builders that tell you rain always falls downwards either.
None of this has any bearing on how deep your pond should be, of course. But it does get really cold in the UK, even in towns now and then.
Just sayin'
I thank you all so much for all your comments and input. There is lots there for me to digest and take away. You've all given me plenty of food for thought. Watch this - work is a good bit underway now and hopefully I will have made much more progress by the weekend.
I've had ponds of all sizes and shapes over the years, and they will freeze depending on the severity of the winter and the duration of the sub zero temps. However, it really does depend on where the pond is, what's round it in terms of planting etc for protection, and where you are in the country. None of mine have ever frozen by more than 6 inches. Two of them have had fish in them. One was very deep in the middle and had a natural, constantly moving water source at one end, so that bit was free of ice but the rest froze quite extensively. The other pond was a 'conventional' sized garden pond of about 18"/ 21" at the deepest point. I'm quite far north, and once ice forms on water, it stays for quite a long time.
I use a piece of polystyrene which has an indentation on the underside. It's tied to the surrounds of the pond with string, wire or similar, and that keeps a space unfrozen.
I live in west central Scotland - not where that photo is...