water seeps in through the floor during floods

[bella123]

We live in a flood plane. We have a sump system which has never quit working. After 4 days of heavy rains, in spite of our sump pump, water starts to seep in from the floor. Our basement is poured concrete. The walls do not leak. Each instance of flooding was deemed a "hundred year flood," and our county was declared a disaster area. Is there anything that can be done to mitigate these extreme circumstances since "hundred year floods" are occurring every 18 months? All suggestions will be appreciated!

[TJ1962]

Maybe sump is only picking up exterior water. A interior drain tile may be installed to pick up water under the slab, and another sump installed due to volume of water.