Sink Hole'd: The Sequel

Some of y'all may recall that when we bought our house, during the closing the previous owners were like "Hey watch out for that sinkhole in the backyard which we didn't previously disclose." At which point we spent $400 to have a contractor  fill in a giant sink hole along our back fence with rocks and dirt, after extending the fence a few feet downwards so all that stuff would be held in and not fall into the creek that's behind our fence.

At the time I was like "Hey contractor, what about that weird pipe underground that seems to empty out near the sinkhole, might that have something to do with it?" So the contractor said it must be connected to one of the pipes connected to one of our gutters, and he ran a hose through a couple of the gutters but nothing came out the pipe.  So he was like "well I bet this is from some prior renovation of the house or something, you probably don't have to worry about it, it doesn't seem to be connected to anything."  And like a chump, we believed him, and he filled in the sinkhole with rocks and dirt and did nothing about the pipe.

Fast forward two years later and suddenly after a couple of crazy thunderstorms (The kind we get in the south where it pours like the dickens for 30 minutes and then clears up) a sink hole opened up right where the old sinkhole was! Randomly in the middle of the ground, and not right next to the fence as would be the case if it was erosion from the creek which caused the sinkhole (Which we decided it was 2 years ago). About 2 feet in circumference and straight down to hell.  And right at the edge of the same pipe!  So we figure, it was probably the pipe.  We could tell it was one of those black plastic landscaping pipes, so B went and got a new 10 foot length of plastic pipe and some bolt cutters at the hardware store. We then dug a trench from the edge of the new sinkhole/pipe to the fence, using some of the rocks from there to fill in the very bottom of the new sinkhole and putting the rest of the dirt on a tarp on the side of the trench, which made it really easy to refill the trench afterward.  B then cut a hole in the fence using the bolt cutters

 On the other side of the fence was nothing when we moved here, since it had all been washed away by that pipe. We've been filling that in and trying to create ground on the other side of the fence by throwing sticks and branches and dead weeds and dead leaves and grass mulch down there for the past two years, and it's been working pretty well at building it up into land. But it wasn't too hard to compact all that stuff down with a hoe, so that there was a clear space on the other side of the fence.

 Then we put the pipe down in the trench, through the hole, where it was long enough to reach beyond our giant pile of sticks and crap, where it will now drain into the creek behind our house, where it should be draining to (the creek is a rainwater collecting place and drains to a reservoir).

 

 View of the pipe from the exterior of the fence.

View of the pipe from the interior of the fence. That root over the pipe is where the new sinkhole originally opened up. The pipe originally extended to that root, but we had to dig back several inches to trim back the pipe, since the end was all cracked and in pieces and we wanted a clean edge to connect it to the new pipe:

In the end we covered up the trench with all the dirt we had dug out, and I added a whole bunch of peat moss I had lying around the shed  + a bag of topsoil we bought at the store, since it wasn't enough dirt to quite fill it up (since the pipe had washed out a lot of dirt from under the sinkhole which we had to fill up too). The trench is now entirely filled on the inside, and since then we've been dumping grass clippings and more sticks on the other side of the fence on top of the pipe there, which is slowly being covered up too.

Then yesterday there was a crazy thunderstorm, so towards the end of the thunderstorm when the rain was dying down we ran outside to see if anything was coming out of the pipe- and there was a crazy huge amount of water pouring out of it into the creek!  No wonder there was a sinkhole there! In fact I'm surprised our solution of rocks + dirt wasn't washed away 2 years ago, it's crazy it even lasted as long as it did!

But now that the source of the problem is fixed, hopefully this won't be opening up ever again. And hopefully we'll eventually be able to slowly rebuild the part of the hillside on the other side of the fence that was washed away by that pipe which apparently has been gushing water underground for 2 years (and who knows how long before it, cause it washed away the entire side of that hill).

Sinkhole solved!