Don't bother using this tag
I think this tag is too broad for categorizing campsites into a mere 4 tiers as well it being too subjective. For example what if a camp site has water but no toilets, or a laundry service or pool but no power for the customers? I suggest adding tags to the tourism=camp_site such as drinking_water, internet_access, pool, electricity, etc then get the data consumer (eg. your mapping app) to filter into tiers if they so desire. This way it is much less ambiguous (easier to map in my opinion) with the added bonus of it being more detailed. And even better would be to map the amenities and relate them to the campsite (with a relation).
It should also be noted that this tag is also already used in Proposed_features/Extend_camp_site and the 80% usage reflects that. So this page should be updated to include that. --DFyson (talk) 01:42, 19 April 2017 (UTC)