Low Spots in Yard

What is a general rule of thumb on when to use sand to level or to bring it more dirt?

Have a few low spots in my yard that consistently hold water and at best they are just muddy slop with weeds. These spots can be driven over with my ZT maybe twice a year during a “drought” period in summer/fall without getting stuck. Im in SE Louisiana.

For additional context, we had bad floods in 2016 and my neighbor said the previous owner thought the flood “reset” the water table and these spots may have been where trees previously were when they cleared the lot 30 years ago. Allegedly these low spots weren’t issues until the flood. Neighbor has a pond near these wet spots but not sure that’s the issue as other areas by the pond are bone dry.

TIA