I discovered it yesterday with my ladder.  Almost went down off the ladder when the foot broke through.  The hole is about 1.5 feet wide, round and four feet deep.  It's only 4 feet from the house.  Should I be worried?  Location is Citrus County near the line with Hernando County.

This is not an easy question to answer as the answer is "it depends".

You can hire an engineering firm to do a study to see if there is a sinkhole further down that could end up taking the house out.

Or you can just fill in the hole and wait and see if the sinkhole develops further.

Would you know the depth to bedrock?

Could there be a utility pipe under the hole?  A sewer line that is leaking could possibly be piping soil which will cause a localize sinkhole above the pipe to form.  If so, then just need to repair the sewer line and backfill.

I'm rural and i know where the underground water lines are so no pipes under the hole for sure.  I don't know how far down the bedrock is but the well driller reported about twenty feet of bedrock.

When I worked for Public Works in SWFL, I ran the camera truck for a while.  I saw many sink holes.  There, it was always a pipe failure.

I know you're rural, but, is there a catch basin in the right of way ?  Is it possible  there is an outfall pipe going into a sump ?

I'm in Citrus Springs, and there are a lot of sumps here.  I see drainage pipes going into them.  If so, it could be old CMP ( corrugated metal pipe ) that rotted through.

Do you have a probe ?  Basically a length of round stock with a "T" handle on it.  I used to poke around the sink hole, and see if it hits something.  Or if I hear a metallic sound.

I would be concerned.  Maybe there's a contractor with a pole cam that could look into the hole.  Not to sound like a dick, you may want to check if your homeowners insurance has sink hole coverage.

Look into GPR ( ground penetrating radar) to map out the extent of the cavity.

If your house is on a slab, GPR can look under the slab too.

I hate to be that guy. Fill in the hole and sell your house while it's still worth something. My brother's nextdoor neighbor had a sinkhole open under their house. The entire house was lifted and several trucks worth of cement was poured under it. It's now uninsurable and virtually worthless.

And don't forget the fatality a few years back when a SH opened and swallowed the home and a fellow sleeping............far as I know that body was never recovered.

I’d be worried.

I'm on a non public right of way that the county does not maintain.  I know for sure that there are no pipes causing it.  I filled it in and will monitor for now.  I'm also going to look into ground penerating radar.....that seems like a good place to start.

Thanks for the map Osprey.  Yeah...a bit dated but still an indicator of active areas.  My area shows no activity within several miles.  I guess it doesn't mean that I can't be the first though.

I had a friend buy and sell one through me that had sinkhole repair done (RamJack system installed) and had no issue getting insurance when he bought it, nor did the buyer have any issue getting insurance when we sold it (not to mention, it still appreciated equally with everything else in the neighborhood) with proof of remediation.

My mom lives by the airport in Inverness and had the engineering study done on her property... 13 sinkholes at the time. Insurance paid her out and it was NOT fixed. I lived there for ten years after that while she was living in TN, and never lost a bit of sleep over it

Do you remember what the study cost?