I don't think anyone knows for sure, because this is a routine maintenance, but they are also adding/updating audio-animatronics along the river, so I don't think we'll know a date until closer to the draining, or when it's actually almost ready to be filled back up.
Since Easter falls on April 4, I bet the River will be back by then. I would think they'll be doing all the maintenance in the relatively slower period between the Christmas and Spring break times. Have a great visit!
The ROA refurb will begin after the Holiday season. It is expected to be finished by March. The new AA's won't take long to be installed and the maintence on the river and the Fantasmic! Fountains usually take at least up to 2 months to finish.
Logically speaking, the Rivers of America should be full again by the end of March.
If any delays happen (which I doubt), then it'll be full by the end of April.
Keep in mind that even if ROA is finished, Fantasmic! will not return until June. The time that the refurb is done, is when Fan! is typically dark (even during Spring Break weeks it's not showing). They will take the time after the refurb to test out Fantasmic!'s equipment and continue nightly rehersals for Murphy as they are still working on it to get it out of B-Mode.
I'm afraid there's some really inaccurate information out there, including in this thread.
I was talking to some of the River Leads late last week, and the rehab is currently scheduled to last from January 4th, 2010 until May 14th, 2010. That timetable is very tight and has almost no slack in it, and it may be extended before January 4th or run later once the rehab starts if we have a rainy winter that stops work for too many days.
The water won't be returned to the River until the first week of May, but once the water is back they have to do about 10 days of testing the Mark Twain and Columbia because the track and track switch will be replaced and full testing is required by the State of California inspectors. Tom Sawyer Island will open first around May 10th while the last of the boat testing happens, and then the full Rivers of America will open on May 14th.
Fantasmic! will also require a full re-mount after such a long downtime. Much of the rehearsals can take place in rehearsal halls, but the full river rehearsals can take weeks, especially testing and adjusting any new showpieces (nothing set in stone, btw).
Expect Fantasmic! to return as part of Summer Nightastic (yep) in June.
I meant including Fantasmic and everything. The above posts didn't mention when Fantasmic would be open again after being tested once ROA is re-filled.
I was just curious as I haven't seen Fantasmic since I was 5 back in early 2000 so I'm dying to see it again!