Swimming Pool Members? I moved into a New Subdivison, only 5 Families live here,...

I moved into a New Subdivison, only 5 Families live here, end year it was brand modern and No one lived here, so they sold memberships to neighbors (not in the subdison). This year since we are here they are going to boundary the outside memberships. Question? People hve been coming from concluding year and NOT paying, they think since they payed closing year they can still come. How can we keep track of who is a associate and who is not? It says on the Pool, member only, but i.e. not stoppping them as the pool is not locked. Any suggestions?
What year be my house built?
Answers:    Home owners association should put lock & valid members obligation key or comination similar to an entry gate into the gated communities do.
Maybe member can hire a lifeguard-gate keeper.
Only honourable way,