The utilities that feed our home include gas for heating, cooking and hot water; electric for everything else; and water. Our septic is an aerator system, they would not allow us to put a septic tank/leach bed on the property due to the proximity to the river. The breaker box is in the garage, elevated on the wall. The garage floor is much lower than the rest of the house.
I think looking into "hardening" the utilities might be good idea---maybe talk to the companies that supply the gas & electricity. I am not at all familiar with the type of septic system you have. As to the others:
Electric: Probably a good idea to cut the main switch at the box if the water starts getting in. However, the mains coming into the box would still be live, so if the box goes under water, who know what might happen. Something to look into with the power company or a good electrician.
Gas: Normally, there is a main gas valve. Make sure you know where it is and cut it off also. Main concern would be stresses on the house causing a gas leak. You don't want that. Again, it might be worth a call to the gas company or certified tech for specific recommendations, if any.