For what it's worth, I'd also be concerned if I found out my neighbor was: stockpiling firearms, making meth in his bathtub, keeping pet tigers, storing 3000 gallons of gasoline in a tank in his garage. I'm not trying to make a direct comparison, just hopefully illuminating the fact that it might not all be about the government "[saving] him from himself"
After criminal damage is done, the state can press charges. Everything else is a very slippery slope.
As an example, imagine your neighbor has a gas stove and accidentally leaves it on, unlit, all day. A pilot light turns on, and the house explodes, causing hundreds of thousands of dollars of damage.
Should the government ban gas stoves? How about electricity?
Finally, stockpiling firearms, making meth in the basement, keeping pet tigers, and storing 3000 gallons of highly-flammable liquid is not the same as having a small swimming pool. The things you list are generally illegal in all circumstances, but having a swimming pool is never illegal. Also, water just isn't that dangerous. The pool collapsing would probably not cause any more damage than watering a tree and forgetting you left the hose on.
So, as I mentioned earlier, you are heading down a very slippery slope. Individual rights should trump the possibility of "inconvenience" to your neighbors.
If anyone should be upset, it's this guy's insurance company.
Can we agree that there is a grey area which covers where lines should be drawn in terms of personal rights vs. infringing the rights of others? It is certainly the crux of our system of government.
We obviously disagree where the line is in this particular case, and I totally respect your vigilance.
I do take issue with your statement "having a swimming pool is never illegal" -- that is certainly incorrect, at least by definition of the building codes in the jurisdiction I live in.
But I agree, we are surrounded by slippery slopes.
2, It leaks and 250,000l of water flows out under the house washing away the soil that the foundations stand on. His neighbours house falls into the hole.
3, The houses were built on a concrete raft (common where the ground is unstable) he has just cut a big hole in the raft, it cracks and his nieghbours house falls over.
That's ignoring the risks from dumping that much water into the drainage system, leaking chemicals, humidity/damp etc.
1, I can't say for sure, but I think it's a free standing garage. Plus it was standing just fine without water pressure on it before he started. Plus water barely puts any pressure outward anyway (most of the pressure is right near the floor).
2, 3,000 gallons is 11,000l. So how is it going to leak 250,000l of water? I don't think any residential water meter could put out that much water in a week! And that for a full pressure leak. So totally bogus.
3, he specifically did not cut into the slab.
That much water? What much water? He's not dumping anything. And if it was a regular pool he would be doing exactly that, without you getting all worked up over it.
You want to explain problems with what he did - fine. But don't exaggerate, and make up non-existent problems.
in any case he'll have to remove it if the house ever goes up for sale, there's no way that would pass inspection. the first thing an inspector will ask for is the permit for the work
House insurance doesn't necessarily extend to a free standing garage, so he might be cleared there too, he just has to hope nothing disastrous happens to it.