The incredible sinking lawn!

[Milliways]

One of my front lawns has 2 areas that keep sinking. DH has filled it in & returfed it twice now, but it has collapsed again.

The holes are at least 1' deep and 3-4' across.

Apparantly previous owner was forever filling them in.

Any suggestions? I am loathe to totally excavate them in case we uncover a mine or something . There are badger setts in the area but no evidence of them coming in garden. It is also near the gas meter so probably pipes going underneath. Could even have been old trees on site.

As holes are >100' away from house, what would you do?

[edam]

Plant some flowers in them?

[jenkel]

No advice, my Mum and Dad had this years ago in our old house, and sorry to say but it was a cave. At first just a small amount of soil dissapeared so they just kept topping it up, then we had loads of rain and the roof of the cave, where it was once a small hole (where the soil dissapeared) collapsed and they had an huge hole, which exposed a small cave, they had to fill it with loads or stuff and put soil over the top. But this had happened it neighbours gardens also over a period of years, the houses had huge gardens and the gardens were over a small cave network.

[Milliways]

Might find Stig of the Dump then?

They just annoy DH as he cannot run the tractor over them - but they must be deep when you consider how much soil we keep adding to them!

[greenbean]

LOL at the cave! If ois a cave you could open it up as a tourist attraction.

[hub2dee]

Could they be on the site of mini water reservoirs where drainage trenches converge ?

Are they in any way 'in line' with each other / the house / manhole covers etc. ?

That's a fairly large quantity of soil to be disappearing / washed away / sinking ! Tread carefully !

[hub2dee]

UFO landing spots ?

[Milliways]

The 2 holes are almost touching, running across the width of the lawn. May be drains etc - our neighbours had a blocked pipe problem last year & they had to dig across the front of our house - but 120' from holes!

These are nearer the road. Can you get maps of pipes & things?

[hub2dee]

I imagine it is something to do with service pipes to your property or your neighbours. You should be able to get maps from the utility companies. I think you can get them when you say you are going to dig sodding great big holes in your garden and you want to check you're not going to hit electricity / water / gas IYSWIM.

Perhaps they represent some kind of junction / access hole to a (large) pipe and the sealed entry to this pipe has failed, so soil is being carried down it... maybe this is what had a knock-on effect for your neighbour (blocked their pipe) or maybe you guys are about to suffer some kind of blockage ?

[Milliways]

Good idea - will try & persue that line.

Good thing we have pipe insurance!