|
WHAT IS A LEVEE?
A levee is a manmade structure, usually earthen embankment, designed and
constructed in accordance with sound engineering practices to contain or
control the flow of water so as to provide protection from flooding during
high water events.
WHY IS LEVEE SAFETY BEING ADDRESSED AS PART OF THE FEDERAL EMERGENCY
MANAGEMENT AGENCY’S (FEMA’S) FLOOD MAP MODERNIZATION PROGRAM?
Levees present an unusual and
extreme hazard. While they modify flood risk, levee systems do not provide
protection from the largest floods and tend to lull people into a false
sense of security. Levees do have limitations and they are susceptible to
sudden and catastrophic overtopping and failure. In addition, information
on levee location, structural integrity, and certification often is outdated
or missing altogether. This information is important for preparing reliable
flood hazard maps.
HOW DOES FEMA EVALUATE LEVEES THAT SHOW AS PROVIDING 100-YEAR PROTECTION ON
THEIR DIGITAL FLOOD INSURANCE RATE MAPS (“DFIRMs”)
FEMA evaluates levees based on
documentation submitted by the levee owner or operator (a reclamation
district or other flood control agency). The documentation must demonstrate
the levee is in compliance with the criteria in Title 44 of the Code of
Federal Regulations Section 65.10, which includes criteria for levee design,
operations plans, maintenance plans, and certification by a registered civil
engineer.
WHAT IS A
PROVISIONALLY ACCREDITED LEVEE (“PAL”)?
A provisionally accredited levee
is a levee for which all the documentation necessary to gain full
accreditation is not readily available. The community and maintaining
agency submit a signed letter to FEMA stating that the documentation will be
provided by a specific date. Provisionally accredited levees are shown as
providing 1% annual chance (100-year) flood protection on the Digital Flood
Insurance Rate Maps (“DFIRMs”), with notes indicating that the levee is only
provisionally accredited.
WHY DOES FEMA USE PROVISIONALLY ACCREDITED LEVEE STATUS AS PART OF THE MAP
MODERNIZATION PROGRAM?
FEMA uses provisionally
accredited levee status as part of the Map Modernization program in order to
issue DFIRMs which provide the community with current flood risk information
while the documentation necessary for the levees to gain full accreditation
is being gathered.
WHAT MUST BE DONE TO GAIN FULL ACCREDITATION FOR PROVISIONALLY ACCREDITED
LEVEES?
In order for a provisionally
accredited levee to gain full accreditation, documentation must be submitted
to FEMA demonstrating that the levee is in compliance with Title 44 of the
Code of Federal Regulations Section 65.10 (44 CFR 65.10), which include
criteria for levee design, operations plans, maintenance plans, and
certification by a registered civil engineer.
WHICH AREAS WOULD BE AFFECTED IF THESE PROVISIONALLY ACCREDITED LEVEES ARE
DECERTIFIED?
The areas affected by the
decertification of a provisionally accredited levee can be viewed on the
DFIRMs and on the “Proposed Flood Zone Changes Map”, both located at
www.sjgov.org/pubworks/flood_info.htm. These areas include Lathrop,
Weston Ranch, Twin Creeks, Boggs Tract, Brookside, Quail Lakes, Lincoln
Village West, Country Club, Rough & Ready Island, and a portion of western
Manteca.
WHEN IS THE DEADLINE FOR THE COMMUNITY TO PROVE THE PROVISIONALLY ACCREDITED
LEVEES ARE IN COMPLIANCE WITH THE CERTIFICATION REQUIREMENTS?
The deadline for the community to
prove the levees are in compliance with the certification requirements (the
PAL expiration date) varies between levee systems depending on when the PAL
letter was submitted by the community and accepted by FEMA. In San Joaquin
County, PALs will be expiring in August 2009, March 2010, and August 2010.
For the expiration date of a particular area, see the “Notes to User” on the
DFIRM, located at
www.sjgov.org/pubworks/flood_info.htm.
WHAT HAPPENS IF THE PAL EXPIRES BEFORE THE COMMUNITY CAN PROVE THE LEVEES
ARE IN COMPLIANCE WITH CERTIFICATION REQUIREMENTS?
If the PAL expires before the
community can demonstrate the levees are compliant with 44 CFR 65.10, FEMA
will decertify the levee and begin the map revision process to show the area
behind the levees in a Special Flood Hazard Area (SFHA) where flood
insurance is mandatory for any property with a federally-insured mortgage.
The map revision process will take a minimum of 9 months to complete, and
may take longer.
DO I NEED FLOOD INSURANCE IF I LIVE IN AN AREA PROTECTED BY A PROVISIONALLY
ACCREDITED LEVEE?
While mandatory flood insurance
requirements do not apply in areas protected by provisionally accredited
levees, there is a residual risk of flooding. Levees and other flood
control structures can only be designed and constructed to provide a degree
of protection from flooding; should they overtop or fail the results would
be disastrous. All property owners in areas protected by levees are
strongly encouraged to purchase flood insurance.
HOW CAN I FIND OUT IF MY PROPERTY IS WITHIN AN AREA PROTECTED BY A
PROVISIONALLY ACCREDITED LEVEE?
The new Digital Flood Insurance
Rate Maps that show PAL-protected areas go into effect on October 16, 2009.
You can find out if your property will be located in an area protected by a
provisionally accredited levee by viewing the DFIRMs dated October 16, 2009,
available at
www.sjgov.org/pubworks. Also on this website, there is a “Flood Viewer”
application that can help you find your specific parcel. If you have any
questions or need any clarification regarding the flood zone changes that
will occur in October, please contact your community floodplain
administrator.
|
