Love this movie. I must have it.
That said ...
Spoiler alert.
Why didn't they just put a porch on Carol's house, if it wasn't going to be flooded? She said that her grandmother could watch the river from there.
I think it is because she resented Carol for marrying Monty. She brushed her aside. And she didn't want to owe anything to anyone.
shareI believe Carol suggested that option initially but her grandma probably felt she had been abandoned by everyone around her including Carol. As Carol told Glover, if grandma had to move she'd probably die. Grandma, no doubt, felt the same way. It was her only chance to be buried on her land with her late husband. It's the only piece of the island that would not flood. In the end, that's what happened.
Woman, man! That's the way it should be Tarzan. [Tarzan and his mate]