Due to the draft of the rig and the depth of the water, the only way to get that rig out of there will be to cut it up in pieces. This is going to be a mess, and the bridge is not built for that kind of impact. This is a mess, ouch. Speaking as a Naval Architect.
Is there any chance the level of the platform will drop with the receding water from the storm surge (or due to rain)?
Awwwww. some ballast and a low tide may do the trick, maybe.
On the bright side the rig didn't hit either of the main suspension towers; those are where most of the time and effort of construction is. Replacing a section of suspended roadbed is (relatively) simple and fast, at least.
Couldn't they flood it down say 5-8 feet instead of cutting the superstructure of the rig?
First thing is to secure it = Keep it from moving and hitting the bride deck (again!) as the river water rises with floods upstream. Tides (even the low Gulf tides will cause more damage as it goes "up and down" against the bridge.
Depth of water? Might need to pump excavate under the floats first.
What is the water depth? How far to deeper water. Dredge a channel?
Would that section of the middle span of that bridge will have to be rebuilt, or most of the span of the whole bridge have to be rebuilt from the impact of that oil rig ?
"Due to the draft of the rig and the depth of the water, the only way to get that rig out of there will be to cut it up in pieces. This is going to be a mess, and the bridge is not built for that kind of impact. This is a mess, ouch. Speaking as a Naval Architect."
So you mean the rig is (or is almost) "grounded" or "beached?"