Hot answers tagged snowdonia
The bottom line is there is always SOME risk. Whether to take that risk or not is your choice. Fast running + isolated + high elevation = prettttty low risk. With that said the biggest concern is, unless you are drinking right from the source, you have no idea what has happened upstream from you. There could be a dead animal snagged in the stream, animal ...
I think your assumptions are correct. To my knowledge in a mountain environment you are quite safe as long as you follow some simple rules, which you mostly already named: The water was not standing, i.e. it comes from a stream that is rather fast and the stream is big enough that it is not just a connection of puddles or ponds where the water rinses ...
I would say that it is a Carabus coriaceus. It might have a size of 30 to 40mm and is very common around Europe. Unfortunately the English wikipedia article is rather tiny: https://en.wikipedia.org/wiki/Carabus_coriaceus
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