Submission + - Beavers are undermining dykes in the Netherlands (theguardian.com)
'But there’s a significant downside to the booming Dutch beaver population. Beavers are increasingly digging burrows and tunnels under roads, railways and – even more worryingly – in dykes. For a country where a quarter of the land sits below sea level, this is not a minor problem – especially as beavers are not exactly holding back when digging.
“We’ve found tunnels stretching up to 17 metres into a dyke. Wide enough for a grown man to fit in. That’s alarming,” says Jelmer Krom of the Rivierenland water board. Rivierenland is a region in the middle of the Netherlands, crisscrossed by big rivers, where dykes are crucial for keeping high water at bay. If a major dyke gives way, it would cause a serious flood affecting thousands of people.'