The Flume ran full season too. My point is that the attraction arrived at a point when the park had a peak season which aligned almost completely with hot months (or at least months which could be hot in the UK!), so it made sense. Since then the season has been extended out in both directions and now there is a second peak around halloween.I do somewhat agree although at the same time, I'd say the likes of Phantasialand, Europa Park and even Efteling seems to run year round and have water rides that run most of the time.
I've heard that Phantasialand even run Chiapas at Christmas.
I'm sure it would still be worthwhile if the park chose to look into something like a Flume or a Water Coaster. Not all attractions at a year round park needs to be year round per say and I've heard some of the more modern water rides including water coasters and flumes can adjust the wetness based on when in the season it is.
Personally, this is exactly what both Thorpe Park and Alton Towers have been missing since 2016. The last pieces of the puzzle I'd say![]()
In a perfect world the park would absolutely have more water rides, but in reality it makes sense to prioritise investments which could theoretically run and be popular year-round. If you look at where investment has been since Merlin took over you can see a trend toward these sorts of attractions - roller coasters and enclosed rides. The park haven't yet really found their feet with their winter offerings but the intention is pretty clear, and I suspect post-Horizon we'll see a bigger push.