There needs to be a set of lines that matches the best information that we have. In areas where flood insurance is optional, such as behind levees designed for 100-year flood protection, FEMA can only urge homeowners to buy the coverage at discounted rates. To keep new development high and dry, some states require that properties be elevated at least one foot above the water level expected in a 100-year flood. That's one foot above what FEMA recommends. But California leaves it up to individual communities and is unlikely to impose a statewide standard.
Some communities resist such industry pressures.
For its trouble, the city's flood insurance rates have dropped. Roseville engineer Garth Gaylord said FEMA's incentives don't drive the city's decision to be prudent, but they help. Likewise, the federal government is promoting regional cooperation on flood control and disaster prevention. If FEMA approves a concrete-lined channel to protect one area, for example, the agency wants to be sure it won't increase the amount and the pace of the flows downstream. Murray said he is encouraged that some jurisdictions, such as Placer and Sacramento counties, are working to alleviate flooding problems that don't respect political boundaries.