The City of Simi Valley has initiated a citywide project to update the National Flood Insurance Program (NFIP) floodplain mapping. The current mapping relies on rainfall data and mapping technologies that are over 30 years old.

 Phase One - Tapo Canyon Creek Letter of Map Amendment

On behalf of the City of Simi Valley, Q₃ Consulting has applied for a Letter of Map Revision (LOMR) from the Federal Emergency Management Agency (FEMA) to revise the floodplain mapping as shown in the figure below.  The City anticipates that FEMA will publish the draft LOMR by May 2024.  Once the LOMR is published, a four (4) month appeal period will begin. If no appeals are filed within that timeframe, the LOMR will immediately take effect.

This area includes portions of the Arroyo Simi and tributaries as follows:

Arroyo Simi – Beginning at First Street to a point downstream of Royal Avenue

• Dry Canyon Channel – From the Arroyo Simi to a point downstream of Cochran Street
• Erringer Drain Channel – From the Arroyo Simi to a point downstream of Kearney Avenue
• Runkle Canyon Channel – From the Arroyo Simi to a point downstream of Arcane Street
• Tapo Canyon Creek – From the Arroyo Simi to Walnut Avenue.

The above map reflects the area affected by the Tapo Canyon Creek Letter of Map Revision 

The Flood Insurance Rate Map (FIRM) for a community depicts the floodplain, the area that has been determined to be subject to a 1-percent or greater chance of flooding in any given year.  The FIRM is used to determine flood insurance rates and to help the community with floodplain management.

 As a result of this LOMR application, the limits of the floodplain will be significantly reduced, and contained within the bed of the Arroyo Simi. This will result in the following:

• 1,903 properties will be removed from the SFHA
• 223 properties will see the mapped flood depth decrease
• 53 properties may possibly be mapped into the SFHA
  • These properties were overlooked in the original mapping effort
  • Separate notices will be mailed to these property owners at a later date.
• Anticipated effective date: On or before September 2024

Maps and a detailed analysis of the flood hazard revision can be reviewed at the City of Simi Valley at 2929 Tapo Canyon Road, Simi Valley, CA 93063.  If you have any questions or concerns about the proposed project or its effect on your property, you may contact you may contact Brent Siemer, Floodplain Manager for the City of Simi Valley, at bsiemer@simivalley.org, or by phone at (805) 583-6805.

 Phase Two – Citywide Physical Map Revision

 The last phase will require much greater time and effort to accomplish. This will involve the City hiring a firm to develop the floodplain modeling and submission of a Physical Map Revision (PMR) application for FEMA review. On FEMA’s part, their consultants will review the application and ultimately prepare all new maps and revise the Flood Insurance Study that documents the changes.

 The anticipated time line for completion of this work is 2-3 years. Updates to the status of this phase of work will be made periodically.