Stunning! I don't think I've seen anything that gives such a good idea of what it is actually like to explore drainage systems. Must've taken ages, big props!
Said it before and will say it again, proper top work mate! Having seen the time spent in Hulme Flume, it's mad to see how short the footage is! Well worth the effort though.
When this first appeared online I must've watched it three or four times consecutively. Wanted to get my waders on and go draining immediately. Staggered by the work involved then (the quantity and quality), even moreso after reading this through.