Thanks, Gilroy! I wonder if anyone has success posting images from their libraries directly to gardenweb? We've gone back and forth--from making the pond into a firepit--which would mean somehow making it drain snow melt and rainwater, to reviving the pond, which means a bigger financial and time committment, plus lots more to learn (just trying to figure out the GPH and the lift and the head height and immersible vs external and direct drives vs mag drives...! Yikes!) We've also talked about making it a firepit surrounded by a pond or somehow making it into a hot tub or outdoor pizza oven. It's the focal point of our backyard and letting it fill up with algae and Mosquitos and weeds every summer just isn't working. Our neighbor put in a swimming pool and all the noisy equipment sits atop the hill just above the pond's retaining wall and behind a hideous chain link fence. We're hoping to cover up the noise with the waterfall sounds and eventually put up our own wooden fence to hide the chain link. But, wow, what a lot of work and expense. I love old houses and am glad you're trying to stay true to the design of your home's era. Have you posted any photos of your home and where the pond is sited in relation to the house? Good luck!

I agree w/ spam. Hiring a structural engineer shouldn't be too expensive. He might tell them forget it, or he might say go ahead. I would think in this case, though, hiring an "expert" would be in order first. We are considering moving our 115 year old house w/a similar foundation situation (plus lots more). We have gotten an estimate on jacking and moving, and it's not as prohitively expensive as you might think. And, if needed the engineering costs on top are also, in comparison, are also not hugely expensive.

annz, thanks so much for the links! Very helpful. I have googled quite a bit but this particular site never came up in searches, must have used different keywords. I'm actually ok with not having the concrete colored off the bat...too scared to be stuck with a color I'm not wild about and I know that happens sometimes. I might stick with plain or experiment with small pieces I'll ask him to pour in a box for me that I can try staining. The broom finish is for non slippage......I love the look of sleek smooth concrete, but it can get too slippery for me. We are always using the patio. Luckily, he's pretty subtle with it, has done work for us before. The grooves are not very deep. Is there another way to finish it that would be smoother but non slip? Adding some sort of granular stuff or exposed aggregate would do it, but we don't really want those either. Anyway, thanks for the help, I really appreciate it!

Of course they can be removed from below by an experienced licensed plumber. You may get a bit of damage right at the drain pipe penetration, but a mud set tile job has a lot of inherent strength to it, and it want be damaged much, unless it has underlying issues caused by an existing leak.