So the opposite of Deism is not Theism where God intervenes in everything. Theism can also mean God interacts with humanity through the Holy Spirit. I don’t personally believe god makes anything happen. I think it’s all choices we make.Don't be ridiculous. Are you a pure naturalist?
You don't think God who makes such a decision would not make certain it all happens as He has said? He watches over His word to perform it.
But that still is not an answer to my question. What do you mean by the flood is supernatural? Like where do you think the water came from and how much of it? Was it enough for 1 mile of land? Or did it cover even the tallest mountains which were around 5 miles tall. Was it all in the sky? Was it 50% in the sky? 2.5 miles of water in the forms of clouds or ice like rings? Did 2.5 come from underground? From how far? Was it magically made in a bowl that angels poured out?