Drainage away from the foundation is one of the best ways to mitigate floods. Make sure your gutter downspouts go as far away as possible from your house and preferably flow downstream away from the house.

A sump pump is pretty common in most modern homes, but they can be installed in older homes, although it can be a pain to install the drain tile and sump pit.

At a previous home, I installed a water-powered back-up sump pump that uses municipal water pressure to suck out the sump pit. It was great if the main sump pump failed or power went out. Battery back-up sump pumps are an option too, but battery maintenance and limited amount of battery life during loss of power is a concern.

Having two separate electric sump pumps on different circuits is another good idea.

A water alarm to sound off when there is water that floods is good so that you can be notified as soon as flooding starts. There are models that work on WiFi and can provide remote notifications.

For my current situation, I have two electric sump pumps and a Generac natural gas back-up house generator that automatically turns on in case of a power outage.