What condition would an abandoned outdoor swimming pool be in years later?

October 7, 2011 7:06 PM

Picture an abandoned outdoor swimming pool. One that hasn't been used in, say, four or five years. Assuming there was water in it and a tarp over it when it was abandoned -- what condition would it be in? Would the water have evaporated? Would it still be present, but slimy and awful? Would the tarp have worn through? Please mention any other details I haven't thought of. (This is for a story, in case you're curious.) Thanks!
posted by webmutant to Home & Garden (24 answers total)

I think this John Updike story might be of interest to you.
posted by drjimmy11 at 7:11 PM on October 7, 2011

There are a lot of factors you haven't mentioned here. Where is this pool? In a temperate climate like coastal California or in the mountains of Michigan? Is it an above ground pool or a below grade pool? Is the area subject to wind such that the tarp might have dust and sand blown across it? How much rain is likely to fall and accumulate on the tarp? These are just a few of the factors that could affect the situation you are trying to describe.
posted by Old Geezer at 7:12 PM on October 7, 2011

Are we talking a tarp or a pool cover (solar or winter cover)? I doubt a tarp would last through the first good storm. A solar cover might fair slightly better, but certainly wouldn't last five years. A winter cover would still be intact, but dirt and sand would work through it and settle to the bottom of the pool.

What part of the world are we talking about? That would impact the evaporation factor.

Is this in a neighborhood with kids? What's the condition of the house? The likelihood of a pool at an abandoned home being left alone for years by kids is pretty minimal.
posted by FlamingBore at 7:13 PM on October 7, 2011

Lets not forget deer & other animals. This can be a real problem with covered pools: They think it's safe to cross, fall through the covering (or thin layer of ice), and never get out.
posted by Ys at 7:15 PM on October 7, 2011

Response by poster: Old Geezer: Good points. Let's say, temperate climate like coastal California; a below-grade pool.

FlamingBore: I guess I mean a proper winter pool cover, yes. And the kids in the neighborhood have pretty much left it alone. Because of the ghosts.
posted by webmutant at 7:19 PM on October 7, 2011

But it isn't air-tight, and after a while, leaks develop. Original water evaporates but rain water gets in so yes, slimy and awful.
posted by Rash at 7:23 PM on October 7, 2011

There would definitely be dead things in it.
posted by fshgrl at 7:30 PM on October 7, 2011

temperate climate like coastal California
I mean a proper winter pool cover

I'm from the area you describe, and I've never even seen a winter pool cover, and we had a pool. I have seen bubbly plastic insulator things.
posted by LionIndex at 7:31 PM on October 7, 2011 [1 favorite]

Best answer: Green and brown slime. Lots and lots of mosquito larvae and other bugs. Possibly a few amphibians depending on region. No fish. A few deceased small mammals in various states of decomposition. Not much in the way of higher order plants. Pretty full, though, as evaporation is going to be low. I'd expect a few small holes in the cover from curious critters/birds/branches falling in pointy end first. Probably quite a bit of leaf litter and other assorted stuff on top, along with waterline stains and UV-related fading. Maybe some torn straps.
posted by seanmpuckett at 7:32 PM on October 7, 2011 [3 favorites]

In the aftermath of Katrina abandoned pools became breeding grounds for mosquitoes. Public health officials populated the pools with mosquito-eating fish to try to control them.
posted by XMLicious at 7:34 PM on October 7, 2011

If it went undisturbed for years, California sunshine during the dry, rainless summers might be enough to dry out and sterilyze everything -- I think a lot would depend on the specifics of this pool cover.
posted by Rash at 7:38 PM on October 7, 2011

Some years my dad wouldn't bother cleaning out the pool in the summer (in LA) because we were too busy. Black algae covered the entire bottom by, say, June, and the tarp would have mostly been submerged under six or seven inches of water. Also, we caught several dead animals (squirrel to possum sized) each year. Never birds.

And the stink. Uck.
posted by SMPA at 7:40 PM on October 7, 2011

Another factor will be the pool's shape. So many have flat bottoms, slanted usually... but in California pools are more curvy and free-form, which is why skate-boarders like them. In fact in Dogtown and Z-Boys you can see documentary footage of preparing unattended suburban pools by first pumping out that seasonal residue.
posted by Rash at 7:46 PM on October 7, 2011

Best answer: I had a 36' x16' in-ground pool and when I was first injured years ago; I could not care for it for over a year.Despite initially super shocking and covering it-I ended up with a green cesspool that was infested with mosquitoes in various stages of development.

Think neon green water / black algae plants growing from the bottom with thousands of black worm -like things squiggling away(and bonus floating fur logs that probably were squirrels). It was EVIL to pump out and clean and I had to get an new liner.This was in Southern Ontario over a full season of temperatures.
posted by plumberonkarst at 8:09 PM on October 7, 2011

Last spring my sister had to get into her pool which had been dormant (but full-ish(?)) for the winter months. She donned her SCUBA gear and jumped in, but got some kind of skin infection that had to be treated with antibiotics. This is after a freezing cold New England winter, I'd guess in a warmish California environment there'd be plenty of bugs and bacteria to getcha.
posted by bendy at 8:47 PM on October 7, 2011

LionIndex - you might know them as "safety covers".

Had an inground pool in New Mexico years ago. After one winter with the winter/safety cover the spring opening showed an emerald green water but not a lot of funk. Not a ton of mosquitoes - but that's NM. Even with that standing water, it's dry.

I don't recall there being any dead animals in the pool as the cover is kept taught to the deck, thus preventing access.

If it had been left through a super hot NM summer I imagine it would get considerably worse.
posted by FlamingBore at 8:56 PM on October 7, 2011

Another post-Katrina observation - all of the blue tarps on people's roofed were pretty much completely disintegrated after, I'd guess, two years. I'm pretty sure they lasted at least a year pretty well (it took almost a year to get a roofer to get around to my roof and the tarp wasn't leaky yet) but were definitely not much more than bits of string well before four or five years after the storm. I don't know if a pool cover is stronger than a blue tarp, but if not, there won't be much left.

Oh and after we had a house fire (no electricity for the pump) our little above ground easy set pool was a green mosquito filled frog pond after only a couple of months.
posted by artychoke at 9:41 PM on October 7, 2011

LionIndex - you might know them as "safety covers".

Nope. Maybe on a spa, never on a pool. My family had a pool, our neighbors had pools, my friends had pools, I've helped design houses with pools, and none of them ever had a pool cover other than an insulating sheet. Not that they don't exist, it would just strike me as strange for a CA pool to have a cover like that.
posted by LionIndex at 9:45 PM on October 7, 2011

Best answer: In many places, the ground water level is higher than the deep-end of the pool. This is certainly true in Florida.

In this case, if a pool is empty of water for a sustained period (6 months), the pool will actually rise out of the ground.

A pool is a big container of water, like a giant bucket. The ground water level is like an invisible lake. A bucket (or pool) that is full of water will sink in a lake (or the ground water). But a bucket (or pool) that is empty will float on top of a lake (or the ground water level).

I have seen this happen a few times in Florida. Empty, neglected pools can rise several feet out of the ground, even taking a concrete side-walk up with them, as the pool slowly beings to "float" on the ground water level.
posted by Flood at 9:46 PM on October 7, 2011

My parents bought a house with a long-neglected pool when I was 16, in Santa Cruz County, California. It had an inch of muck and dead leaves on the bottom, the water was green and had a visibility of about 6 inches, and was filled with all the various water bugs that you find in a pond -- water striders, mosquito larvae, backswimmers, etc. It stayed full. The water evaporates slow and rain refills it. Frogs swam in it at night and raccoons drank out of it. We eventually tore it out.
posted by tylerkaraszewski at 9:47 PM on October 7, 2011

My mother-in-law had a pool like this in CT, uncovered until about a year and a half ago. Turned into a pond, with frogs, turtles, flora. Now it's covered and was hyper-chlorinated about a year ago, but the next time I go down there, I'll peek and see what kind of goo is festering therein and memail you. You've been warned. Actual data is on the way, though not for a few months.
posted by FauxScot at 4:19 AM on October 8, 2011

Best answer: Flood makes a good point for areas with high ground water, but in arid So. Calif. I would not expect this. I have owned four homes in So. Calif with pools, including two that I built. I also managed two resorts with several pools. The chemicals in the pools are very unstable. They would be, for all intents and purposes, gone in the first warm month. The pool would become the slime pit several people have described above. Along the California coast the rainfall would probably not quite keep up with the evaporation rate if the cover was of good quality and well-fitting. Five years is a long time, so the pool would probably be around half-full of slimy green sludge and the carcasses of small rodents and garden creatures. When the cover was removed or pulled back there would be a terrible stench. As the water would have gone bad well before evaporation started, the exposed walls of the pool would be coated with successive rings of green stains where the water level went down, paused, went down, paused, etc.

If you have such a pool, remind me not to be around when you take off the cover. If one of your characters stashes a body in it, the neighbors will know immediately that it has been opened.
posted by Old Geezer at 8:24 AM on October 8, 2011 [1 favorite]

There's a good chance that lawn furniture has blown in and is slowly sinking into the mire.
posted by davey_darling at 10:59 AM on October 8, 2011

Response by poster: Thanks, everyone -- this all gives me more than enough information for my story. Much appreciated! If you like horror, MeMail me if you'd like a copy of the story when it's done.
posted by webmutant at 1:33 PM on October 10, 2011