In reply to Tall Clare:
That's my trouser size and Quechua trousers for 40 pounds fit me, guess with trainers there might be a gap where my socks would get wet, i've not noticed/can't remember checking, but with boots on they're fine, and with gaiters on they're more fine.
Only trouble with them is they're not so breathable, and the zips can be a tad iffy. I cut the mesh lining out of mine to make them lighter and to stop my boots catching as much, which might have something to do with the dampness which I feel. Under really hard exertion they don't breath well at all though, when i've been tree clearing when it's been raining and the air's felt damp and there's been mist in the air, my trousers underneath have wetted out rather.
Have sewn together the top of one two way zip which used to open all the way up, and it's fine to use with a large gap for my boot, I guess you could nip the iffy zips in the bud and sew them together at the top so they're like those on most waterproof trousers.
There are better trousers out there, but I think they'd be fairly okay for anything that's not involving exerting as much effort as possible or making a lot of sweat.
Tim