Surf Snowdonia faces opposition to plans for a 106-bed hotel and activity centre offering 100 new jobs.
Community councillors in Dolgarrog back the £10m plans at the artificial lake, sited on a former aluminium works.
But opponents, including Snowdonia National Park, fear traffic congestion and the scheme's visual impact.
Planning officers said concerns about flood risk and contaminated land should also be addressed before Conwy councillors approved any scheme.
A zip wire, over the existing surf lagoon, stretching from the proposed five-storey activity building would also be included, according to the Local Democracy Reporting Service.
Surf Snowdonia said the scheme would offer 100 new jobs as the attraction's camping pods would be replaced by a four-storey hotel, including a gym, spa, sauna, treatment rooms, restaurant, conference and other function rooms.
Snowdonia National Park said it objected because it felt the building design was out of character and that the size and capacity of the scheme was excessive, complaints mirrored by the Campaign for the Protection of Rural Wales.
Conwy Valley Civic Society and Conwy council's own highways department have also raised issues about increased traffic.
However, Dolgarrog Community Council said the traffic concerns were unfounded and claimed the scheme would boost visitor numbers and have a positive impact on small businesses in the village.
Meanwhile, the Welsh Government's environmental arm, Natural Resources Wales, said it wanted more assurances over potential flood risks to the site, as well as measures to cope with possible unknown land contamination resulting from the site's industrial past.
Conwy council's planning committee is due to consider the application on Wednesday.
A report by planning officers said they supported the idea in principle, and did not think the scale and design of the buildings were unacceptable.
They have recommended the plan be rejected though, until issues including flood risk, drainage, land contamination, ecology and highway matters had been "fully addressed".