Depends. Refing [[Stroudwater Navigation]] was a pain
in the neck even
though I had the main source in front of me the whole time.
[[Canal#Features]] would be much more of a pain. The problem is that
it jumps between levels of complexity so some you would be looking at
citeing from a school textbook and others from wighter tomes.
The effort required is such that if I was required to do it that
article would still look like this
http://en.wikipedia.org/w/index.php?title=Canal&oldid=132489555
Which isn't really B class despite the claims on the talk page (I
would argue the current version is just about).
You don't have to specify exactly which source each statement comes
from (although it is preferred where possible). Just listing the
references at the end of the article would be acceptable.