We bought our house about a year ago, in Chesapeake, VA. It has 33k gal IG vinyl pool that is approx 13 years old. For various reasons, we did not have time to comb over the house before purchasing, and depended on inspectors and realtor to be our eyes. A creek runs the length of our property line; about 10' of land separates the creek from the bottom of a steeply sloped hill, upon which the pool and house sit. It is not unusual during periods of high tide and a good nor'easter for the creek to flood the lower portion, up to the base of the hill. It's happened twice in the year we've lived here.
Pool inspector's report revealed no problems, but stated the water was too murky to inspect the pool too far below the water line. After moving in, and clearing the water, it became obvious there was at least a 3.5" difference in water level from the shallow to the deep end, and that the south west corner (deep end) of the pool dipped quite a bit. Once the water cleared, we could see a depression in the wall on that same corner, close to the bottom. The pool didn't leak, but novice pool owners that we are, we knew a bowl in the side of your pool couldn't be a good thing. We called the pool inspector, who said he didn't perceive the dip as a problem since both skimmers worked. He said vinyl pools will sometimes develop a depression like I was describing, but if it wasn't leaking, we could wait to address it when the liner was replaced.
The skimmers do work, but we have to fill the pool up to almost the lip of the dipped corner so the skimmer closest to the house works, but then the skimmer on the hill side seems sluggish.
Anyway, we made arrangements to replace the liner. Liner Guy came out, looked the pool over, we discussed the dip, and he said it looked as if it had settled all it was going to settle, and since the skimmers worked, all should be well. We have plans to build retaining walls around the slope, and he said that would be a good idea. I should mention that the concrete deck starts sloping toward that low corner just past the shallow end of the pool, and while there are no large cracks in the concrete slabs, the space where the slabs come together have widened, especially at the low corner. Ok, well, that's two experienced pool builders that say it doesn't look like we have a problem. So not only do we replace the liner, but have the pool converted to SW and have a new DE filter installed. So we've got about 5k invested in this pool, which is ok, as we very much enjoy it. When the old liner was removed, the depression and a couple of cracks were repaired, but other than that, they said the floor and walls were great shape.
That dip really nags at me; however, and I wonder if there isn't something major happening here. I've noticed a gouge in the hill coming down from that corner where rain water must be eroding it. About 20' off that same corner, the previous owners had a very large oak tree removed, and I wonder if its decaying root system could be causing that side of the hill to slide.
When the company who did our liner came out to open the pool this spring, I asked about the pool deck because they also build pools, and he said it could be raised. I didn't question him any further because he wasn't the builder, but did he mean raise the whole pool, or just the deck? And if just the deck, what do you do with that 3.5" difference between the height of the new deck and the lip of the pool? We will have to replace the deck eventually anyway. The previous owners apparently really liked slate, and had chunks of it arranged in the concrete around the pool, creating a toe stumping gauntlet, that may effectively keep the kids from running around the pool, but has almost caused me to trip in several times, so they must go!
So, should I call in a geophysical engineer or something. Can a decent pool or landscape person reliably fix this problem? Where do I start?
Thanks to anyone who takes the time to read this, and especially to anyone who can point me in the right direction.