I fished the severals several times but it was back in the 90's. It was not a prolific stretch for me in fact did better in the day ticket water above the bridges however, had some fish. Back then it was still more or less the gallons of hemp and maggots boys on swim feeders before the pellet and boilie was just coming in.
I often found a pattern on the Avon fishing swim-feeder style, first the small fish, then the chub would muscle them out and then the barbel would move in that is if they were feeding of course.
But by far I found the best way and more pleasant way to fish was free lined cheese. Cheap as chips which by the way I also heard worked on occasions and had both barbel and chub on the cheese.
Put a piece of cheddar (super market packets just as good) about a 1/2-1 inch or bigger on occasions. I would thread a baiting needle through the cheese and then pull the hook back through and twist it and pull back into the cheese just until the hook disappeared. I could cast a long way with this with a well loaded fixed spool right up to the lip but a bit of grass might help on longer casts and depending on the cheese used but the rubbery supermarket cheddar was pretty good in this respect.
I would look for gaps in the weed and cast above them and let the cheese trundle down judging that it would hit the bottom in the gap and keep paying out line until it settled. Some of the thicker fronds where they are swaying are clear beds underneath, casting to the edge of the sway and the cheese would pass through to the bottom but experimenting on the bank will help so try eye and judgement, but heavy-ish weeded water not impossible. Then prop the rod up with a bow in the line and wait and watch. The weed would make the line move but bites were generally obvious. I would pick the rod up and lower it and give plenty of time for the fish to get the cheese in the back of the mouth, strike too early and the cheese would pull from the lips. Practice and judgment got better with both the casting and striking as time went on but more importantly, just understanding what I could do and not do with it. With the weed the cheese would easily pull through it when retrieved, with no weights swim-feeders, shot etc and fish snagging was not much of a problem either although I still had to bully them a bit to keep them getting in the weed but it was only a case of getting them on top and keeping them there, I think I was using 12lb line at the time or was it 8lb, can't remember but bear in mind the thinner the line the less resistance to current and wind.
So with a couple packs of cheese, hooks, rod rest and net quite a lot of water could be covered, I think there is quite a lot of the severals you could try maybe (is it 3 miles of water) if this tickles your fancy.
Plenty of good chub and barbel caught in different places on the Avon, moving swims after 15 20 mins in each, no ground-bait, cheese is smelly and if a fish was there they would latch on but lob a few freebies in as you wish.
Old fashioned way of fishing but I found it very good on the Avon and ended up always fishing like it in the end.