[jyl]

I read that, for those without flood insurance, the best they can get is a low interest federal loan. For those with flood insurance, I read typical limits are 25% of house replacement cost. I have not found data on average homeowner's equity in Houston.

You see where this is going. What % of those homeowners who were flooded will ultimately abandon their homes and default on the mortgages? Some won't be able to make them habitable again, others will lose them when they can't service the increased debt.

And of those who manage to hang on, what % will be at substantial probability of defaulting after the next flood - remember that Houston has been having major floods (though nothing like Harvey) every few years now.

I'm thinking a whole bunch of Houston-originated mortgages are now worth much less than a few weeks ago. Four days ago the early estimate was 400,000 homes with agency backed mortgages were likely damaged, but no-one really knew the full scope. And there will be some non-agency backed mortgages too.