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The TSUNAMI_INUNDATION dataset represents coastal areas that might be inundated by tsunami waves during a tsunami event. During a tsunami, usually a series of ocean waves rushes towards land and inundates or floods otherwise dry land.

This TSUNAMI_INUNDATION_LINES dataset represents the maximum expected run-up line of inundation during a tsunami event. During a tsunami, usually a series of ocean waves rushes towards land and inundates or floods otherwise dry land. The tsunami inundation lines coincide with the landward side of the tsunami inundation polygons.


Tsunami modelers, geologic hazard mapping specialists, and emergency planners produced a series of tsunami inundation maps for the State of California, spanning mainly the populated areas of the coastline. The initial tsunami modeling was performed by the University of Southern California Tsunami Research Center and funded by the California Governor’s Office of Emergency Services. The inundation line represents the expected maximum inland penetration of inundation. According to the Method of Preparation notes on the maps:

The accuracy of the inundation line shown on these maps is subject to limitations in the accuracy and completeness of available terrain and tsunami source information, and the current understanding of tsunami generation and propogation phenomena as expressed in the models. Thus, although an attempt has been made to identify a credible upper bound to inundation at any location along the coastline, it remains possible that actualy inundation could be greater in a major tsunami event.

According to the Purpose of This Map notes on the maps:

This tsunami inundation map was prepared to assist cities and counties in identifying their tsunami hazard. It is intended for local jurisdictional, coastal evacuation planning uses only. This map, and the information presented herein, is not a legal document and does not meet disclosure requirements for real estate transactions nor for any other regulatory purpose.

The inundation map has been compiled with best currently available scientific information. The inundation line represents the maximum considered tsunami runup from a number of extreme, yet realistic, tsunami sources. Tsunamis are rare events; due to a lack of known occurrences in the historical record, this map includes no information about the probability of any tsunami affecting any area within a specific period of time.

For more information, visit the California Department of Conservation website:


The California Governor’s Office of Emergency Services (Cal OES), the University of Southern California (USC), and the California Geological Survey (CGS) make no representation or warranties regarding the accuracy of this inundation map, nor the data from which the map was derived. Neither the State of California nor USC shall be liable under any circumstances for any direct, indirect, special, incidental or consequential damages with respect to any claim by any user or any third party on account of or arising from the use of this map.

Because of this dataset’s reliance on information or materials from outside sources, the County makes no warranty, representation, or guarantee as to the content, sequence, accuracy, reliability, timeliness, or completeness of this dataset.

This dataset is for reference purposes only and any reliance upon it will be strictly at your own risk. This dataset is presented on an “as-is” and “as-available” basis WITHOUT ANY REPRESENTATIONS OR WARRANTIES OF ANY KIND, EITHER EXPRESSED OR IMPLIED, including, but not limited to, implied warranties of merchantability or fitness for a particular purpose. Do not make any business or other decisions based on the dataset before making an independent determination based upon whatever information, in your discretion, you deem to be reliable, reasonable and appropriate, including, but not limited to, validating your decision with the appropriate department, agency, or organization, as warranted.

The County is not responsible for any damages of any kind, including, but not limited to, special, indirect, incidental, punitive, or consequential damages, that may arise from the use of, or the inability to use, the dataset, or that result from mistakes, errors, or defects, whether the dataset is provided by the County or an outside source.

Data History:

Data for the Los Angeles County mainland was initially provided in 2008 by the California Governor’s Office of Emergency Services (CalOES)/Earthquake and Tsunami Program. In December 2011, data was provided by CalOES that included not only the mainland, but also Santa Catalina Island.

The original datasets were modified (“cleaned up”), as follows: 1) Some of the inundation lines were not coincident with the inundation area polygons when zoomed in close. Those lines were slightly adjusted to make them coincident. 2) The inundation lines for Santa Catalina Island had unresolved problems, and were recreated. 3) In some places, the side of the tsunami inundation polygon toward the ocean overlapped the land, based on the County boundary that was utilized by the data creators. Those areas were adjusted to match the DPW_COUNTY_BOUNDARY dataset. Now the side of the polygon toward the ocean originates approximately 100 feet from the County boundary (shore). The landward sides of the tsunami inundation polygons were not adjusted. 4) The tsunami inundation polygons for the mainland were originally created as a series of connected polygons. For display purposes, those boundary lines between polygons were not meaningful. Those polygons were merged to create a seamless inundation zone.

Click here to download Tsunami Inundation data.

Click here to download Tsunami Inundation Line data.

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Data Field Descriptions


No attribute fields, other than those maintained by ArcGIS.


No attribute fields, other than those maintained by ArcGIS.

GIS Source Information
Database Name: eGIS_Hazards
Feature Dataset Name (if applicable):
Reference Date: 2011
Accuracy: Other
Update Frequency: Unknown
Access Constraints:None

Contact Information
Margaret Carlin
GIS Project Supervisor
Los Angeles County
Chief Executive Office
500 W. Temple St.
Room 781
Los Angeles, CA 90012
(323) 980-2295

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