Water comes from the atmosphere, it is drawn up from the lakes and sea, and is deposited in precipitation from clouds (which are a collection of water particles and dust particles), as it spreads over the ground and dissapates into rivers, it eventually reaches the sea again.
Dam[n]! You re right. By the way, before it was built and the valley dammed, wasn t there a flood in Newlyn along the lines of Boscastle, with boats gathering up people from houses by the Newlyn Bridge area. I have a feeling I have seen early photographs of this but can t put a date on it!
I have got a photograph of one of the floods; there was more than one flood; I have not yet uploaded the picture, but will before long. The river used to be used to feed the mills and so was diverted into (I think) three mill leats; I have more work to do on the Newlyn side of things.