HomeMy WebLinkAboutAGENDA REPORT 2012 0418 CC REG ITEM 10N ITEM 10.N.
Ity Council Meeting
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TO: Honorable City Council
FROM: Dave Klotzle, City Engineer/Public Works Director
DATE: April 6, 2012 (CC Meeting of 04/18/12)
SUBJECT: Consider Results of Flood Mapping Analyses for the
Walnut Canyon Drain
BACKGROUND
In 2005, the Federal Emergency Management Agency (FEMA) updated the Digital Flood
Insurance Rate Maps (DFIRM) covering the City of Moorpark. The updated maps
showed approximately 1,600 properties newly added into the revised 100-year flood zone
requiring flood insurance for most of these property owners. The City appealed the
proposed changes and revised the maps which became effective on January 20, 2010
and included approximately 1,300 properties in the flood zone. In March 2010, FEMA
approved a Letter of Map Revision (LOMR) which removed all 240 residential structures
from the 100-year flood zone within the Villa Del Arroyo Mobile Home Park.
In February 2010, the City hired MR Consulting (MRC) to analyze the January 20, 2010
DFIRMs to determine if the maps should be revised to more accurately depict the Special
Flood Hazard Areas (SFHA) within the City. SFHAs are developed by the Federal
Emergency Management Agency's (FEMA) flood mapping procedures and indicate areas
that may experience one foot or more of flooding due to a 100-year storm event. Flood
insurance is mandatory for properties with a mortgage and with a structure located within
an SFHA.
The initial phase of analysis performed by MRC was focused on the Arroyo Simi and its
lack of capacity to contain the 100-year storm flow resulting in areas of flooding within
the City. MRC corrected the hydraulic model used to create the January 20, 2010
DFIRM flood zones attributed to the Arroyo Simi and on behalf of the City, submitted a
request for a Letter of Map Revision (LOMR) to FEMA in June 2010. On January 28,
2011, FEMA issued the approved LOMR and revised DFIRMs with an effective date of
June 13, 2011. Approximately 861 properties within the City were removed from SFHAs
with approximately 241 remaining in a flood zone. All affected property owners were
notified of the LOMR and invited to a public workshop which was held on March 24,
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2011 where the results of the LOMR and related flood insurance issues were
discussed.
Additional measures have been taken to determine if more of the properties remaining
in the 100-year flood zone may qualify to be removed from SFHAs or be eligible for
lower flood insurance premiums. These measures included 1) a LOMR for the Walnut
Canyon Drain related to the area of Walnut Canyon Road, Charles Street and Walnut
Street (discussed further below); and 2) ground elevation surveys on individual lots on
Harvester Street, Elderberry Avenue, Justin Court, Villa Campesina Avenue and
Fremont Avenue. The elevation survey also included the Woodcreek and Moorpark
Pines Apartment buildings as well as the Park Springs Condominium complex.
The surveyed ground elevations of four properties on Elderberry Avenue enabled them
to be removed from the SFHA and four other properties on Elderberry Avenue may
qualify for lower flood insurance premiums due to the elevation of the properties
compared to the calculated 100-year flooding elevation. Additionally, the surveyed
ground elevations of twenty Park Springs condominiums and four of the Woodcreek
Apartment buildings enabled them to be removed from the SFHA. Approximately 113
of the remaining properties that were surveyed will remain in the SFHA based on their
surveyed ground elevations. The owners of all the surveyed properties were notified in
writing of the resulting effects of the survey on their property.
DISCUSSION
The additional LOMR effort to determine if the Walnut Canyon Road, Charles Street
and Walnut Street area can be removed from the 100-year flood zone has been
completed. This effort included the analysis of the Walnut Canyon Drain starting at the
detention basin north of Meridian Hills Drive, proceeding south past City Hall to the
point where it turns west along the railroad tracks.
On March 1, 2012, FEMA issued the approved LOMR and revised flood zone map for
this portion of the Walnut Canyon Drain with an effective date of July 18, 2012. Sixty-
nine properties were removed from SFHAs as a result of this most recent LOMR.
Letters have been sent to all affected property owners notifying them of the revisions to
the flood zone map along with information they can use to process the cancellation of
flood insurance policies and possibly obtain refunds of premiums after the effective
date of July 18, 2012.
On May 18, 2011, City Council approved the additional analysis of the lower reach of
the Walnut Canyon Drain heading west of Gabbert Road, then south between the SCE
substation and the proposed Moorpark West Studios site, and then west along the
north side of Los Angeles Avenue until it joins the Gabbert Canyon Drain which turns
south and empties into the Arroyo Simi. The results of this analysis have verified that
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no further LOMRs or changes to the mapping of SFHAs in this area are warranted at
this time.
Since FEMA's update of the DFIRMs in 2005 which included over 1,600 properties in
the 100-year flood zone, the City's efforts to accurately map the flood prone areas have
successfully removed approximately 1,456 properties from the 100-year flood zone.
These properties are no longer required to carry Federally mandated flood insurance,
however, FEMA encourages property owners near a flood prone area to carry flood
insurance and lenders can impose their own requirements for flood insurance.
No efforts to further revise the DFIRMs are planned at this time, however, the City will
continue to coordinate with FEMA and the Ventura County Watershed Protection
District to evaluate and pursue opportunities to improve the level of protection against
flooding within the City. The City will continue to provide flood zone mapping and
insurance information to affected property owners as necessary.
FISCAL IMPACT
On November 18, 2009, the City Council appropriated $100,000.00 from the General
Fund Reserve to fund efforts to revise the DFIRMS and remove as many residences from
the 100-year flood zone as possible. On May 18, 2011, the City Council appropriated an
additional $50,000.00 from the General Fund Reserve to complete the flood zone
analyses and DFIRM revisions. Of the $150,000.00 appropriated, an estimated
$135,000.00 will be spent on these efforts.
STAFF RECOMMENDATION
Receive and file.
SAPublic Works\Everyone\Reports\Staff Reports\2012\April\04-18-2012 Walnut Canyon Flood Mapping Results.doc 283