[hnlmorg]

Lego survives being eaten by babies and poop back out again (source: my younger brother). They also survive being left out at theme parks (ie the various Legolands) and primary schools under all weather conditions for months and years.

So I don't think I'm underestimating the resilience of Lego bricks to flooding.

There was an article a on HN a while back about the plastics chosen by Lego. They put an exceptional amount of time and effort into choosing durable materials for their bricks.

[plorg]

Only tangentially related, there was a "500-year" flood in my region a couple of years ago and a manager in my department who would shortly become the company president had his house flood. I volunteered to help with cleanup and ended up at his house tearing his basement, at one point 8' under water, down to the studs. His near-adult kids had small Lego collections that were basically in untouched condition except they had been under water. He told us to throw them out with everything else - it was not worth the complicated effort to do them and sort them out. But out of all the stuff it took us the most convincing to do so, the bricks weren't damaged at all.

That said, I'm surprised Lego survive outdoors. My understanding is that ABS is not UV-resistant.