A key part of good planning as it relates to flood protection would seem to be the acceptance of an optimal standard—a 500 year level of flood protection—already met by most major river cities in the country including Tacoma, St. Louis, Dallas, and Kansas City, rather than accepting the minimal 200 year level as adequate.
New Orleans had a 250 year level of protection prior to Katrina.
An excellent graph can be seen here http://www.levees.water.ca.gov/history/floodprotect.cfm
Editorial: Flood of progress
FEMA, new laws signal a notable change
Published 12:00 am PDT Friday, October 12, 2007
Common sense would seem to dictate that managers of the National Flood Insurance Program would not allow homes to be built in floodplains that lack a minimum standard of levee protection.
But this is the Central Valley, where common sense has rarely prevailed on flood control. Over the years, government authorities have looked the other way while developers have built tens of thousands of homes in places vulnerable to deep, potentially deadly flooding.
That is starting to change.
Despite lobbying by Sacramento officials, the Federal Emergency Management Agency has informed the city it will not approve a designation allowing unrestricted building in Natomas while its levees are being upgraded.
FEMA's decision could have implications for other Valley communities with suspect levees. It is one of several encouraging signs that California soon will be managing its floodplains in a less reckless fashion.
