After Hurricane Ida slammed into the Louisiana coast in August 2021, it took more than 100 lives and cost billions of dollars in damage. To some here, the storm’s coming was just one more justification for a desperate measure to preserve the state’s coast by intentionally flooding parts of the state. Experts say they do not want to sound alarmist, but they believe they cannot be successful in restoring the coast without using the resources of the Mississippi River. That plan has far-reaching implications for the environment and the residents along the project’s path.