Think about your property and the position of your coop. Is your coop likely to flood? How is your coop anchored? Could it blow away? Is there an overhanging tree that might fall on it or have branches fall on it? If you feel the coop is in relative safety, I'd lock the birds in it with food and water and ride it out. If you do not think they would be safe I'd get two larger plastic totes (or a large plastic dog kennel, but this is much more expensive), put straw or towels in the bottom and bring the ducks inside. If you have two totes you can put the ducks in one with a towel and food and water, and when it gets gross (which won't take long) switch them to the other tote, throw the towel in the wash and clean out the one they were in and then when the other tote gets gross switch them back. It may be very little space, but it's safer and better than the alternative, and you will worry less about them by having them close, and it's only temporary. Good luck. Hopefully the flooding and damage in your area isn't too bad. Maybe stock up on extra bottled water for the ducks in case your electricity and/or water supply is compromised.