There are lots of reasons this wouldn’t work, but yours isn’t one of them. Plenty of coastal cities have already done this on a small scale, whole neighborhoods are built on fill- back bay in Boston, marina district in San Francisco just to name a couple. And as a bonus, a good strong earthquake turns it to soup, so every so often you can wipe the slate clean and start over.
There are lots of reasons this wouldn’t work, but yours isn’t one of them. Plenty of coastal cities have already done this on a small scale, whole neighborhoods are built on fill- back bay in Boston, marina district in San Francisco just to name a couple. And as a bonus, a good strong earthquake turns it to soup, so every so often you can wipe the slate clean and start over.