I suspect that part of the problem is that there are no hotels actually near the water park. Its closer to residential areas. There is a Days Inn on Hunt Club Road that would be closer than being downtown and there are a few small motels on Prince of Wales Drive that would be closer as well. I live about 10min (if that) from the new park and I work downtown. As long as its not rush hour, I can get to work and back in about 40min so that would be about your timeframe if you book a downtown hotel.