A WRE type ride in Frontierland does not to use the old concept. Just update it for today's audience.
and if you say it would be too similar to Splash or Pirates they can update the flume tech. Someone said Water coaster tech or what about drops where you go backwards ala Maelstrom ride at Epcot.
Discovery Bay would work much better in the Motor Boat and Autopia area. It's a perfect land... a combination of Fantasy and Tomorrow. Plus having a Volcano Mountain in the Northeast corner of the park would be awesome.
Of course you would have to reroute the monorail and peoplemover track, but what about using a portions of the People mover track for the Journey to the Center of the Earth vehicle. Some changes to the track would need to be made, but I like the idea of having the vehicle traveling through Tomorrowland before or after the JTTCOTE show.
I would miss Autopia but a smaller version can go into a Carsland expansion.