Updating FEMA’s Flood Insurance Rate Maps
Levees reduce the risk of flooding, but no levee system can eliminate all flood risk. A levee is generally designed to control a certain amount of floodwater. If a larger flood occurs, floodwaters will flow over the levee. Flooding also can damage levees, allowing floodwaters to flow through an opening, or breach.
Levees in fair or poor condition are more susceptible to breaching. Knowing this, FEMA has mandated that properties behind levees that have not been evaluated (or levees that do not meet a 1 percent annual chance flood protection levels) are automatically included in special flood hazard zones on the FEMA maps. Owners of properties located within the FEMA-designated 100-year floodplain maps are required to carry flood insurance.
Provisional information obtained from initial levee evaluations was included in FEMA’s revised Flood Insurance Rate Maps (FIRMs) that became effective in August 2009. The District completed remedial levee repairs along portions of Alameda Creek in 2012 (see Evaluating and Improving Levees) and Sulphur Creek in 2013, so FEMA reevaluated maps and published final FIRMs in 2012. Levee certification data were submitted by the District through a Letter of Map Revision to FEMA. Once FEMA processed the letter, FIRMs were changed to show that levees are fully accredited to meet protection levels required for a 1 percent annual chance flood. Owners of property near the levees will then be eligible for low-cost flood insurance.
What’s Your Flood Risk?
FloodSmart.gov is a great resource for lots of information about flood risk and insurance.