Flood Frequently Asked Questions

A levee is a man-made structure (usually an earthen embankment) designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from flooding for flows up to a certain amount.

A levee system is a flood protection system that consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are designed to work together to provide some degree of protection for an identified geographic area and are constructed, operated, and maintained in accordance with sound engineering practices.

A project or State-Federal levee is a levee that is part of the facilities of the State Plan of Flood Control (SPFC). Facilities of the SPFC include levees, weirs, channels, and other features of the federal and state authorized flood control facilities located in the Sacramento River and San Joaquin River drainage basins for which the Central Valley Flood Protection Board (CVFPB) or the Department of Water Resources (DWR) has given the assurances of nonfederal cooperation to the United States required for the project, and those facilities identified in Section 8361 of the Water Code. Also, levees that protect lands lying within the Tulare Lake Basin, including the Kings River, and the Kern River Basin are not State-Federal levees, even though geographically, these lands are considered part of the Central Valley. The facilities of the State Plan of Flood Control are listed and described in the State Plan of Flood Control Descriptive Document.

Local, State and federal agencies are continuing to improve the flood management system; but, no matter how much protection is provided, areas within the natural floodplains of rivers and streams will always face some flood risk. Levee systems are designed to provide a specific level of protection. So “residual risk” refers to the risk of flooding that exists in an area from potential floods that exceed the design of current protection systems and due to the chance that the existing system could experience an unexpected failure. Several factors can cause levees to fail such as erosion from wave action, rodent burrowing, and unauthorized encroachments. Furthermore, levee improvement projects that increase the level of flood protection can actually increase flood risk if additional development occurs in the protected flood-prone areas.

Under Water Code Section 9121, DWR must provide an annual notice of flood risk to each property owner whose property is located in a LFPZ.

Levee Flood Protection Zones do not affect whether flood insurance is required for specific properties. Flood insurance is required for any building with a federally backed loan located in a Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Zone (called a Special Flood Hazard Area [SFHA]) beginning with the letter “A” or “V”, regardless of whether the property is also located in a Levee Flood Protection Zone. You can visit FEMA’s Map Service Center at http://www.msc.fema.gov/ to view Flood Insurance Rate Maps for your area. DWR recommends that flood insurance be purchased for properties located within LFPZ’s even if it is not required by FEMA.

Most standard homeowner, renter and business owner policies do not cover losses resulting from flooding. To be sure what your existing policies cover, check with your insurance agent.

The Community Rating System (CRS) is a voluntary incentive program offered to local communities participating in the National Flood Insurance Program (NFIP) that results in policyholder premium discounts based on activities that communities undertake above the minimum required for NFIP participation.

To find out if you would be eligible for a National Flood Insurance Program premium discount through the Community Rating System, contact your local insurance agent.

Any trained and licensed property and casualty insurance agent in good standing with the Department of Insurance is eligible to write a policy for flood insurance through the NFIP. To find a trained flood insurance agent, you may call 1-888-435-6637 or visit http://www.floodsmart.gov.

To find out how much it would cost to purchase flood insurance for your building and/or contents through FEMA’s NFIP, contact your local insurance agent. While there are numerous underwriting factors that go into the determination of flood insurance premiums, flood insurance rates are set by the FEMA and should not vary from one insurance agent or company to another.

There are a limited number of private insurers who offer flood insurance not backed by FEMA. You can check with your local insurance agent to see what might be available to you.

A Preferred Risk Policy offers low-cost coverage to owners and tenants of eligible buildings located in the FEMA’s flood insurance rate map zones B, C, and X for communities that fully participate in the NFIP. Ask your local insurance agent if you qualify for a Preferred Risk Policy.

Most of the State-Federal levees are maintained by Local Maintaining Agencies (LMAs), which are funded through the assessment of landowners within their boundaries. However, DWR maintains levees and associated roads in the Sacramento River portion of the system for approximately 300 miles (levee miles). If an LMA cannot operate or maintain a State-Federal levee according to acceptable standards, DWR or CVFPB is authorized to create a maintenance area and take responsibility for that levee.

No single entity is solely responsible for levee system design, construction, and operation and maintenance. Some levee systems were originally built by citizens to protect their properties from flooding. Others were subsequently built by various Federal, State or local entities. The US Army Corps of Engineers has designed and built many of the nation’s levee systems, and is responsible for the maintenance of federally owned levees that are in the US Army Corps of Engineers program. However, not all of the levee systems built by the US Army Corps of Engineers are federally-owned. In most instances, levee system ownership has been transferred to the State or to another local or regional authority, which then becomes responsible for operating, maintaining, and documenting the levee system.

Each year, DWR prepares a Local Agency Annual Reports document, based on information submitted to it by LMAs. This provides, for each entity, information relevant to the condition or performance of the levee or levees under its jurisdiction, a description of levee maintenance activities and costs, and contact information. These annual reports can be accessed by visiting http://cdec.water.ca.gov/lma.html. Hard copies can be obtained by mailing a request to DWR/DFM, 3310 El Camino Avenue, Sacramento, CA 95821 or by e-mailing a request to  Flood@water.ca.gov.

Each year DWR inspects and reports on the levee maintenance performed by the LMAs. To view or download the Annual Inspection Report, visit http://cdec.water.ca.gov/fsir.html. The webpage also provides a number of summary reports, including Levee Inspection Results Summary by LMA, and detail reports, including Detail Levee Inspection Reports.

The California Department of Water Resources (DWR) has prepared and the Central Valley Flood Protection Board (CVFPB) has adopted a Flood Control System Status Report (FCSSR) for the State Plan of Flood Control. This report is to be updated periodically, as determined by the CVFPB. The FCSSR includes an identification and description of each facility, an estimate of risk of levee failure, a discussion of the inspection and review to discover any deficiencies, and appropriate recommendations regarding the levees and future work activities.

LFPZ maps are to be used for informational purposes only; they have no regulatory authority. Water Code Section 9130 requires DWR to prepare and maintain LFPZ maps, using best available information. Property owners can visit http://gis.lfpz.water.ca.gov/lfpz/ to view their property location on a LFPZ map by typing in the address of the property. Additional information for the property will include nearby flooding sources, and whether their property could be flooded to a depth of 3 feet or greater if a State-Federal levee fails.

The levee flood protection zone maps were created based on the best available topographical data, provided by the United States Geological Survey. Due to data limitation, flood depths could not be determined for some areas. These areas are designated as "depth unknown."

DWR, under the Central Valley Floodplain Evaluation and Delineation (CVFED) Program, is in the process of developing maps with more accurate flood depths. It is planned that LFPZ maps will be updated once the new CVFED data is available.

BAM are not the same as LFPZ maps. BAM maps have been prepared by DWR to delineate the floodplains for both the 1 percent annual chance flood and the 0.5 percent annual chance flood using the best information currently available. LFPZ maps do not delineate flood frequency. LFPZ and BAM maps differ in the floodplains they cover.

FEMA maps, including Flood Insurance Rate Maps (FIRMs) and the newer Digital Flood Insurance Rate Maps (DFIRMs) are developed specifically to support the National Flood Insurance Program (NFIP). Unlike LFPZ maps, FIRMs and DFIRMs delineate the boundary of the 1 percent annual chance floodplain (FEMA defines as Special Flood Hazard Area) and include flood insurance risk zones; DFIRMs and the newer FIRMs also include regulatory floodways.

DWR has updated BAMs to display the latest 100-, 200-, and 500-year floodplains in a web viewer located at http://gis.bam.water.ca.gov. For questions regarding FIRMs, you can contact a FEMA Map Specialist at the FEMA Map Information eXchange (FMIX): https://www.floodmaps.fema.gov/fhm/fmx_main.html.