While the structure "has not been condemned", it does need investment, according to Denbighshire councillor Glyn Williams, chair of Clwyd Leisure which runs the attraction.
Councillor Mick Bennett, chair of tourism and leisure at North East Lincolnshire Council, said under the five-year agreement the beach was inspected three times a year, and any growth manually removed.
Stoner's ability to create a "seemingly worryless world of leisure and entertainment" was praised by the chair of the judges, curator Martijn van Nieuwenhuyzen.