I'm not sure if it's permitted to run land drains into the mains drainage system ... I think @raisingirl might be able to advise on that one.
No, quite right Dove, it's not. In some areas (usually towns and cities) the sewers are 'combined' which means they take rainwater and foul drains but it is only permitted to drain the roofs of buildings, not of streets or gardens or any other surrounding areas. Nor are you allowed to run ground water into sewers - so if you had an underground stream or a well, you still wouldn't be allowed to discharge it into the sewers. In many places the sewers are strictly foul only and no rainwater, including from roofs, can be discharged into them - you have to have a soakaway in the garden.
A guess would be either you have a soakaway from your roof into your garden and it's become clogged or reduced or damaged in some way. Or your drain to the sewer is broken and it's surcharging into your garden during heavy rain.
Gardening on the edge of Exmoor, in Devon
“It's still magic even if you know how it's done.”
I'm not sure if it's permitted to run land drains into the mains drainage system ... I think @raisingirl might be able to advise on that one.
Good point. Someone suggested it to me because they knew others who have done it. I am not sure of the legalities of tapping into a mains drain and best look into that. Thank you.
Is that an outbuilding in the neighbouring garden to the left? Does it have gutters or does the water simply come off the roof into your garden? Just a thought.
It's a garage. And yes there is a gutter that runs into a water collection drum which we use in the summer. The drum is full now so I imagine the overflow is running into the garden. I better check on that one in case the contribution is more than I assumed.
I'm not sure if it's permitted to run land drains into the mains drainage system ... I think @raisingirl might be able to advise on that one.
No, quite right Dove, it's not. In some areas (usually towns and cities) the sewers are 'combined' which means they take rainwater and foul drains but it is only permitted to drain the roofs of buildings, not of streets or gardens or any other surrounding areas. Nor are you allowed to run ground water into sewers - so if you had an underground stream or a well, you still wouldn't be allowed to discharge it into the sewers. In many places the sewers are strictly foul only and no rainwater, including from roofs, can be discharged into them - you have to have a soakaway in the garden.
A guess would be either you have a soakaway from your roof into your garden and it's become clogged or reduced or damaged in some way. Or your drain to the sewer is broken and it's surcharging into your garden during heavy rain.
Thanks for your input.
I shall refrain from diverting floodwater in to the drain then. Seems there is no easy solution. There is no broken sewer or water discharging from the roof other than potentially some from the garage roof.
I think the only solution must be to extract the clay soil and replace it with better soil...and raise the level of the garden a tad also. I just cannot think of any other way round the problem. Building a soakaway in clay soil would provide only a temporary reprieve as it would clog up very quickly...so I am told.
Thing is, if it's the soil, why don't your neighbours have the same issue? Geology can be variable, it's true, but not THAT variable. So there's something amiss. If you are sure your drains are all working correctly, then either there's a buried slab from an old shed under your lawn, or your garden is, for some reason, exceptionally compacted, or you are at a low point for the entire neighbourhood. If I were you I wouldn't jump straight to replacing the soil. At the very least, do a permeability test (dig a hole, fill it with water, see how long it takes to drain away). You may find a clue just by digging a deep hole at the worst point. You may need to take up the lawn, rotavate and then relay it (or put down new grass). If you really are the neighbourhood sump then the soil is not the issue and you need to consider a different type of garden without a lawn. Just changing the topsoil seems like an expensive way to (probably) not solve the issue.
Gardening on the edge of Exmoor, in Devon
“It's still magic even if you know how it's done.”
Thing is, if it's the soil, why don't your neighbours have the same issue? Geology can be variable, it's true, but not THAT variable. So there's something amiss. If you are sure your drains are all working correctly, then either there's a buried slab from an old shed under your lawn, or your garden is, for some reason, exceptionally compacted, or you are at a low point for the entire neighbourhood. If I were you I wouldn't jump straight to replacing the soil. At the very least, do a permeability test (dig a hole, fill it with water, see how long it takes to drain away). You may find a clue just by digging a deep hole at the worst point. You may need to take up the lawn, rotavate and then relay it (or put down new grass). If you really are the neighbourhood sump then the soil is not the issue and you need to consider a different type of garden without a lawn. Just changing the topsoil seems like an expensive way to (probably) not solve the issue.
Thanks for this.
I have dug a hole at the worst point. I did this last year. The water takes ages to absorb away. When I dug up the soil and made it wet I could roll it up like sausage and bend it like plasticine.
So last year I dug up the worst offending 6m wide by 2m section, to a depth of 18 inches and replaced it with topsoil. It worked a treat at the early part of the winter but as it has got wetter and wetter it is now flooded again. But then again the sections either side of the replaced section are heavy clay soil still.
I have calculated my garden is the lowest point in the road, which could be part of the problem.
I will go out there tomorrow as the forecast is rain again and watch all the gutters, etc, and see if I can detect anything I hadn't thought of.
One way or another I am going to resolve this problem.
As far as I can see, digging clay out and replacing it with good soil is just creating a sump ... the water will still collect there and it’ll be a bog garden.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Yes. If your garden is acting as a sump for the neighbours' gardens, you'll always have an issue. The idea with the paving is to put it in the drier areas and to then plant the wet bits with other plants that are happy with wet feet in winter. You need to do your research on which ones will suit that situation but there are plenty that do. Your paving needs a good layer of hardcore under it so when it gets wet the water also stays below the surface, at least most of the time. If you take off the top soil and put down hardcore to replace it then pave over that, so you don't change the finished level, you can build your raised beds, also potentially with a hard core layer at the bottom and use your own top soil mixed with compost and grit to fill them. On a very wet day, you'll probably still get ponding, but it should drain away quicker, the plants won't mind it too much (if you chose them carefully) and you probably wouldn't be out in it anyway.
Grass is a good absorber of rainwater but only if it's long grass - like meadow grass - so that's another option if you're into your wildlife gardening. It doesn't look tidy in winter though.
I'm suggesting you turn the problem around really - the problem is not the water, it's that lawns don't like a) clay soil and b) being flooded. So you can spend lots of money and energy trying to get a lawn to work where a lawn doesn't want to be. Or you can just plant other stuff that doesn't mind those conditions and make a beautiful, wildlife friendly garden while also making your life much easier.
Gardening on the edge of Exmoor, in Devon
“It's still magic even if you know how it's done.”
Posts
In many places the sewers are strictly foul only and no rainwater, including from roofs, can be discharged into them - you have to have a soakaway in the garden.
A guess would be either you have a soakaway from your roof into your garden and it's become clogged or reduced or damaged in some way. Or your drain to the sewer is broken and it's surcharging into your garden during heavy rain.
“It's still magic even if you know how it's done.”
I shall refrain from diverting floodwater in to the drain then. Seems there is no easy solution. There is no broken sewer or water discharging from the roof other than potentially some from the garage roof.
I think the only solution must be to extract the clay soil and replace it with better soil...and raise the level of the garden a tad also. I just cannot think of any other way round the problem. Building a soakaway in clay soil would provide only a temporary reprieve as it would clog up very quickly...so I am told.
What a pain...
If I were you I wouldn't jump straight to replacing the soil. At the very least, do a permeability test (dig a hole, fill it with water, see how long it takes to drain away). You may find a clue just by digging a deep hole at the worst point. You may need to take up the lawn, rotavate and then relay it (or put down new grass). If you really are the neighbourhood sump then the soil is not the issue and you need to consider a different type of garden without a lawn. Just changing the topsoil seems like an expensive way to (probably) not solve the issue.
“It's still magic even if you know how it's done.”
I have dug a hole at the worst point. I did this last year. The water takes ages to absorb away. When I dug up the soil and made it wet I could roll it up like sausage and bend it like plasticine.
So last year I dug up the worst offending 6m wide by 2m section, to a depth of 18 inches and replaced it with topsoil. It worked a treat at the early part of the winter but as it has got wetter and wetter it is now flooded again. But then again the sections either side of the replaced section are heavy clay soil still.
I have calculated my garden is the lowest point in the road, which could be part of the problem.
I will go out there tomorrow as the forecast is rain again and watch all the gutters, etc, and see if I can detect anything I hadn't thought of.
One way or another I am going to resolve this problem.
What kind of garden without a lawn do you mean?
Raised beds and paving?
Pond and flower beds?
Pond in paving?
Gravel with shrubs?
“It's still magic even if you know how it's done.”
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Interesting thought, paving my garden and doing away with my lawn. Thanks so much for the photos and the help you are giving me.
So if I pave my garden what happens to the water then? Won't it just sit on top of the paving? Won't I have to drain it away somewhere?
The idea with the paving is to put it in the drier areas and to then plant the wet bits with other plants that are happy with wet feet in winter. You need to do your research on which ones will suit that situation but there are plenty that do. Your paving needs a good layer of hardcore under it so when it gets wet the water also stays below the surface, at least most of the time.
If you take off the top soil and put down hardcore to replace it then pave over that, so you don't change the finished level, you can build your raised beds, also potentially with a hard core layer at the bottom and use your own top soil mixed with compost and grit to fill them.
On a very wet day, you'll probably still get ponding, but it should drain away quicker, the plants won't mind it too much (if you chose them carefully) and you probably wouldn't be out in it anyway.
Grass is a good absorber of rainwater but only if it's long grass - like meadow grass - so that's another option if you're into your wildlife gardening. It doesn't look tidy in winter though.
I'm suggesting you turn the problem around really - the problem is not the water, it's that lawns don't like a) clay soil and b) being flooded. So you can spend lots of money and energy trying to get a lawn to work where a lawn doesn't want to be. Or you can just plant other stuff that doesn't mind those conditions and make a beautiful, wildlife friendly garden while also making your life much easier.
“It's still magic even if you know how it's done.”