Rob
A river local to me I know very well. Yes, there are indeed barbel in there. At the moment it's mainly known as a grayling river, but actually there's just about every English freshwater species going (and a couple of semi-saltwater species as well) in there - one single trotting session I had last year produced chub, wild brownies, roach, bream, dace, gudgeon, perch, a small common carp and a couple of eels. Sadly no barbel or grayling on that one.
However, some caveats - barbel were only first introduced in 2009 and, whilst there have been annual stockings (carried out by Keynsham AA themselves) along several stretches since, nothing big has come out (or, at least, been reported). A few 4lbers have come out, and I eventually caught a couple up to about 2lb (average seems to be 1-1 1/2lb) last year, so they have taken. However it's still early days and, whilst the river itself is a very rich environment very suited to barbel, as they aren't a natural species in there it's still unknown as to whether we will ever see them establish themselves to such a degree that it becomes a monster holding small river of the future. The other problems with the river are that it is incredibly snaggy on the bottom for most of its length (most regulars will only float fish it, and most of them target the grayling), and for most of the year much of it outside Keynsham town (and the stretch running into and through Keynsham is one you want to avoid, really) is inaccessible due to bankside vegetation. And I'm not talking a bit of 4ft high stinging nettles that you can easily stomp down with wellies and a big landing net - I'm talking 8-10ft high solid plants that come in a good 10-15ft from the bank that effectively make a wall. You'll need an industrial strength strimmer to get through that lot. That being the case, on one of the stretches where Keynsham AA have a mile and a quarter on one bank, there are literally only three fishable swims all year bar winter when everything has died back.
But it's a lovely little river, largely ignored by most Keynsham AA members (Century Ponds is the club's main draw, followed by some lower stretches of the Avon which are popular with the club's pike anglers), and they're one of the few clubs round these parts that takes restocking very seriously - aside from barbel, roach, rudd and bream have been reintroduced in very large numbers in the last few years as they were in decline.
It's definitely a nicer river than the Brue, with far more variety, but on the other hand there's a lot less river that you can actually fish because of the access issues, whereas the Brue has miles of open bank all year round.
But, as you say, it's £22 a year, which is a bargain even if you don't bother with any of the other venues on the ticket.