Children under 10 should still be supervised in any play area .... Report ALL anti social behaviour - get video evidence...
If there are parents present this behaviour is less likely to occur.......
You want your kids to play, get a rota with other parents and reclaim the play areas. Simples x

Would you have the skate park / bike track outside of your house. I certainly wouldnt Isnt there a boys club, sea cadet unit and an army unit in the town ? also various football and rugby clubs ?
My aunty lives by the new one and its sheer hell. Bored and want somewhere to hang out...build a shed in your garden and let them hang out there instead of making lives hell

If teenagers are the problem why don't they build a skate park or a bike track then they wouldn't need to use the younger kids playground.Not all youths are feral most of them are just bored and want some where to hang out.

“Since the dispersal order cleared the town centre, the playgrounds have become the place where people meet." What? Has she ever wandered around the town centre at night during the weekends? Obviously not.
If she did she would encounter the feral youth hanging around the off-licences swearing, shouting, fighting, arguing, littering etc.