Which shows (again) that you do not understand science.
The idea is irrelevant. As long as it is testable and falsifiable, it does not matter what the source of an idea is, science can have its say.
And as luck would have it, a global flood is nothing but testable and falsifiable.
Scientists have in fact tested and falsified a global flood. Meterorite Craters Refute Young-earthism.
Many aquatic species are sensitive to specific ecological conditions such as narrow ranges of temperature, salinity, acidity, turbidity. How did they manage to survive a violent global flood?
Where is the evidence of a pan-species population bottleneck?
A turbulent global flood should have sorted sediments generally by size and weight. Larger and heavier sediments should have settled first while smaller and lighter sediments should have been deposited above that. But that isn't what we see.