Large dip in my yard

[Meena Nayak]

A large area in my yard is dipping and it slowly spreading. The house was built in the early 80s. I don't know if this is soil settling in or due to a cracked/broken water or sewage line. The water company people have told me there is no excess water recording in my meter, so it's probably not a water line. But there there is no odor, either, to indicate a sewage line bust. What could be causing this dip? I don't even know who to call for help--a plumber or a landscaper. Please help.

[Professor Darvon]

It could be a new gateway to hell forming.

[Anonymous]

Call your city or county offices and ask if they have a geologist (or someone) on staff who can advise if the land around you is subject to "sinkholes".

Where we are, small ones are common due to the underlying ground being very rocky as we are only 1/2 mile from a major river, and rock quarrys.

We also get small rocks appearing in the lawn each year as they work their way to the surface.

House was built in the 1950s, and we had a small sinkhole open up last year. Nowhere near the water or sewer lines.

[trader_4]

It could be some decaying material that was buried, eg tree stumps. From my experience, settling of the earth isn't a symptom of a leak. Water emerging is. If it's leaking, that doesn't normally remove material to form a depression. If this is in an area known for sinkholes, then I'd be concerned. Otherwise I'd just monitor it and/or deal with it. You could have topsoil brought in to level it, but may have to do that more than once until it's done.

[Dan Espen]

Lots of relevant information missing. Like where you live, dimensions of the depression, maybe some pictures.

Have you considered picking up a shovel and digging a hole in the center of the depression. You shouldn't have to dig too deep to get some hints.

[Peter]

You haven't provided enough information to narrow down the choices. If you're in an area with a lot of limestone, it could be the start of a pending sink hole. Are you in an urban area which has had community water and sewer service for 100 years or so, or a relatively new suburb which only received those services around the time your house was built? When you bought your house, you probably had a title search done. Perhaps that would show if there was a previous dwelling on that land. Property tax records may be another way to tell, because if there was a dwelling, the property was likely taxed at the "developed" versus "undeveloped" rate. If there was a dwelling, it may have had a cesspool and associated drainage field, or a large shallow dry well. Was the property part of a farm pasture with a large in-ground pond to provide drinking water for livestock? Any chance that there used to be an in-ground ornamental or swimming pool? Do you have community sewage or might it be your own cesspool and drainage field? Do the downspouts from your roof gutters drain onto the surface of the ground or do they enter a pipe and go somewhere you can't detect (if so, probably into a dry well). All these issues need to be considered when trying to figure out what's causing the land to sink. I'd start with a landscape engineer if you need help determining what's the cause and how to deal with it.

[Ed Pawlowski]

Many possible reasons. Location would help. Could be a sinkhole forming from the deterioration of limestone. Whole houses have fallen into some. This will help you sleep better tonight

[FromTheRafters]

As others hace said, more information would be halpful. It could also be a water well not properly retired.

[hubops]

... it's usually nothing to worry about - but then again ..

John T.

[rbowman]

Was your house built on a landfill?

[micky]

Exactly. Esp. how deep is it. Do you live in Florida or near the Dead Sea?

But be sure to tie a rope between your waist and a tree!

[Colonel Edmund J. Burke]

Did you suck it?

[Ed Pawlowski]

One opened up here in FL a week ago Rope would be needed as it is 50 feet deep. Someone almost did go down.

[Dan Espen]

That could ruin your day.

Here in NJ we can mostly trust the ground we walk on.

I have a few 8 foot circles on my property that subside an inch or 2 a year. The result of tree roots rotting away long after the tree is cut down.

[Clare Snyder]

could even be an old stump finally rotting away

[micky]

I read a story once, that one of the big authorities on sinkholes was at the Dead Sea doing work, took a walk at 7 in the morning, and fell in a sinkhole. Friends didn't notice he was missing for an hour and it took an hour to find him.

I mislaid the tabs, but there have been a few in Baltimore over the years. I saw one just last summer starting in the right half of a street not far from here, and I was trying to find out if a water leak was involved. Maybe tomorrow. 2-lane road, I drove around it, but 10 minutes later when I wanted to come back, the police had blocked off the road.

Aha. I'll bear that in mind -- I'm about to lose a 40 foot tree.

[TimR]

On Wednesday, October 14, 2020 at 11:44:30 AM UTC-4, Meena Nayak wrote: The water company people have told me there is no excess water recording in my meter, so it's probably not a water line. But there there is no odor, either, to indicate a sewage line bust.

Storm sewers aren't the same as sanitary sewers and in my experience are much more likely to break and cause settling or sinkholes; they usually don't smell. But usually the spot is pretty specific. If you have general settling of a bigger area it's not likely that.

Could it be a grave?

[gfretwell]

Until building departments got serious about job site waste, everyone's yard was a land fill. They buried all the trash. You were lucky if your house wasn't built on the neighbor's building waste.

[gfretwell]

Sinkholes up there are usually caused by pipes breaking. We have a different issue down here. Our sinkholes are caused when we pump out so much of the ground water that the limestone caps over the aquifers collapse. Sometimes that happens naturally but pumping the water out as fast as we do speeds up that process. Buried organic matter can still cause those mini sinkholes in your yard tho. You just don't need a rope to pull you out of the hole.

[gfretwell]

Sometimes those storm drain lines didn't even use gaskets between the pipe sections and they would fail. We had a 50+ year old one do that here. Eventually the water ate out enough dirt around the pipe that it collapsed. The worse it got, the worse it got. They ended up cutting out a 5' section of road to fix it.