http://forum.fellrunner.org.uk/showt...edbergh&page=7
Check out Post 67 for the map.
Water is fine. Take a bottle to fill up on the way round.
Best water sources are at the beck below CP2, at CP3, Langdale (between CP3&4) and the last spot is at CP4.
There are a few others as well, but bear in mind that CP4 is probably the last reasonable spot.