Kim, the term "Cajun Navy" actually was spawned during Katrina. That's when these guys first popped up during a disaster in modern times. When the city was closed and civilians weren't allowed into New Orleans, these guys in fishing boats found back ways in with their boats to pull people off roof tops. Many, many people are alive because of them. They're the same guys who saved thousands of lives during the massive floods of South Louisiana last year. You may not have heard of them before Houston, but they're part of the fabric of Louisiana -- they're "regular guys" who just show up when needed, organizing using social media. They've inspired a lot of others -- there are hundreds of people from other states who are on the way, posting on pages like "Louisiana Cajun Navy" asking for the staging area and Zello channel in order to stay in communication -- they've got a surprisingly sophisticated Internet comm systems in place, with a huge number of volunteers working from home. They even have a dispatch channel on Zello.
As for using the full military in domestic operations (other than the Coast Guard and National Guard), it's worth reading some of the history of the the Posse Comitatus Act (a post-Civil War statute), which was passed to limit the powers of the President to use the military domestically against our own citizens -- though there are some exceptions (including disasters) now:
That's wonderful! I wish there was something more that I could do, other than pray and donate money. If I tried to go down there and help, somebody would probably just end up having to rescue me..Individuals and groups from my state are sending boats,supplies,and personal to help.Also several animal rescue groups have pooled their resources and are driving down to bring back displaced pets until they can be reunited with their owners.