The country's ministry of the environment says natural erosion caused the arch to fall.

该国国家环境部称自然侵蚀导致拱门倒塌。

So, even though people have taken all the gold out of the river that was there, new gold will be deposited or put into the river by this natural erosion – at least, I think that's what Heather is saying.

所以，即使人们已经从那里的河流中取出了所有的黄金，新的黄金也会通过这种自然侵蚀沉积或放入河流中——至少， 我认为这就是希瑟所说的。