Hi keith,May be what you're looking for.I just had a look on the C&CC site and there is a nice looking site on the banks of a river within walking distance to pershore.Wyre Mill Club £15-16 a night Members Only - You can join on site
Phone number: 01386 552079
Phone number: 07957 771854 correct co-ordinates 52.120052, -2.065793
Also a CL a little further upstrem Avon bank meadow
Looks like a good weekend if the weathers good

Contacted the organisers of the event and they contacted the council. 10 hour ticket on civic centre car park is £4. May need two if freedoms bum sticks out onto another bay. Overnight is free as is Sundays so Plumb festival looks like it just needs the English Summer to make it a good bank holiday event. 8 quid a day, for two bays that's continental prices.