Illegal rave, drug use, ASB, human excrement

An all-weekend rave has taken place over the last two weekends, continuing from Saturday evening until Sunday afternoon. There is extremely loud music, tents, drug use, people in advanced states of inebriation (very dangerous next to a river), public indecency, people using the river bank as a toilet, and disturbance of the river wildlife. The path is obstructed and the music is deafening. There's litter everywhere from their drinking and smoking. What used to be a quiet, peaceful morning walk with our dogs is now like Soho at 3am. I've reported to the police and they couldn't care less.