If you can't beat them, join them.
Why not try to flip the problem on its head instead? I understand that your team is at a loss to prevent them but maybe the skateboarders see this area as a complete waste of an asset at night when it is no longer being used. There could be a real opportunity here to present this space as something that is convivial and inclusive for all. You may find that the BCA of inclusion as opposed to determent could be more beneficial but to do this you need to see it as a considered option. Perhaps there is a need within the local area to give young people a space that gives them a viable alternative locally, otherwise it sounds like the very expensive option of replacing the pavement treatment.
Glenn makes a valid option with this too.
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