I was just at the park on Saturday 3/21 and didn't have too many crowds...I am guessing the day you go will see similar conditions. Granted, not everything was a walk on but we were able to do all of the major coasters and the log flume in about 5 1/2 hours (were there from about 2-7:30)
Here's what our wait times were:
Falcon's Fury ~30 mins, around 2 or 3pm
Kumba-two train wait
Log Flume ~45 mins, this was around 4, if you go when it's not as hot I'm sure the line is more reasonable
Cheetah Hunt -probably the longest we waited, I wanna say maybe 45-50 mins
If you're getting there at opening definitely knock out Cheetah Hunt first, then if you want to do the water rides, go to them right afterward. Around 5 or so the park will start to noticeably clear out aside from Cheetah Hunt. By mid- to late-afternoon the B&M's are typically walk-ons. Scorpion is only running one train so if you want to do that you'll probably have to wait (had a posted 60-minute wait all day last Saturday) or save it for nighttime. You should have a good time if you use the busiest parts of the day to look at animals and save some of the rides for a little later in the afternoon. All in all there will be crowds most likely but they won't be to the point where you'll have a bad trip. You should easily be able to ride everything within the park's operating hours.