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Interactive map to view risk of flooding from dam failure in Los Gatos

Interactive map to view risk of flooding from dam failure in Los Gatos

The risk of flooding from dam failure in Los Gatos appears to be mainly from four reservoirs, all tying into the Los Gatos Creek at some point or another. Recently Clair found a great resource for better understanding this risk, and we wanted to share it with our readers.

  • There’s an interactive map (link below) that shows most, maybe all, of our Santa Clara County dams and where flooding could happen should the dam fail
  • Additionally, Valley Water has in depth info on a downloadable PDF that actually shows how deep the flooding could be (link below)
    • Some areas of Los Gatos could experience 20′ of flooding or more in case of a breach at Lexington
    • This level of information is not part of the disclosures we get when buying and selling homes. Instead it is listed as “in” or “not in” an inundation from dam failure zone

The usual home seller disclosures include a natural and environmental hazard report, but the info does not go into deep detail. For instance, it may state that a location is in a zone of potential flooding from dam failure, but it does not tell the reader which dam it is. At times I’ve sold homes that were in that designated area but wondered whether the dam was a smaller or larger one (my concern being how much water could come through).

Now, more of those questions can be answered by visiting the state of California’s Dam Breach Inundation Map Web Publisher.

Dam failure flood zones in Santa Clara County


This site is very easy to use and to understand. The dams are marked with colors to indicate the downstream risk. Larger dams that spill into more populated areas appear to be those at higher risk, but perhaps they have a different formula for that designation.

Once you zoom in to your desired area (most counties appear to be participating, and MOST dams appear to be included in this publication), just click on the colored box and wait for the information to populate. It is sometimes a little slow, but after a few seconds it will appear.


Where are the Natural Hazards in Los Gatos?

Where are the Natural Hazards in Los Gatos?

Where are the natural hazards in Los Gatos?

People relocating here often ask about the natural hazard zones in our area, such as:

  • earthquake fault zones
  • 100 year flood plains
  • liquefaction areas
  • landslide zones
  • radon
  • high fire hazard severity zones
  • and they wonder if they’ve missed anything else?

Quick resources to get you started

There are two quick and high level resources to help with a basic understanding of where these zones are.
First, the Los Gatos General Plan 2040 has a lot of good info online. It’s a PDF, so not interactive, but it is a great starting point in getting to know the natural hazards in Los Gatos.

Second, the Cal OES My Hazards Awareness site, which I discuss below, is an interactive website with clear imagery that provides a high level sense of where the various hazard zones may be.

Resources to learn about the Natural Hazards in Los Gatos

There are many good and interactive websites with detailed information and after getting a broad feeling from the general plan, this is my preferred next step.

A great interactive resource for seeing several of the zones at once is the California Office of Emergency Management My Hazards Awareness website. The visuals are pretty good overall, but if you click on what appears to be the San Andreas Earthquake Fault, the map doesn’t provide additional information, unfortunately. As a starting point in a consumer’s research, though, it’s extremely useful.


Natural hazard zones for Los Gatos as shown in the Cal My Hazards website


The CAL OES My Hazards Awareness website, screenshot pictured above, covers the state mapped natural hazard zones, but not the local (county or city or town areas). Also it does not cover flooding from dam failure or levee breaches,  as dams and levees bursting is considered a man made hazard, not a natural one. The CAL My Hazards site does include earthquake faults, liquefaction zone, the high fire risks in the state responsibility areas (not the local responsibility areas),  100 year flood plains, landslide areas, etc.

Important: The fire zone does not appear to be updated on the CAL My Hazards site. The best map for understand the high fire hazard severity zones and similar areas is using the CAL Fire site, FHSZ Viewer (Fire Hazard Severity Zone Viewer).

Local hazard zones