Friday, March 28, 2014

How to know if your home is in a known hazard area

La Plata County has numerous hazards that have been mapped or identified. The most commonly known is Flooding. The FEMA DFIRM maps are used to identify homes that may be inundated in a 100 Year flood event. If your home is a a flood zone and you have a mortgage than you probably know because you likely pay for flood insurance. Did you know there are maps for wildfire, geologic hazards and snow load as well?

Here is how you find your home and the known hazards

To find your property in relation to the Flood Plain:

  1. Open the County Public GIS Portal
    1. Direct right here: http://lpcgis.laplata.co.us/LaPlataSL/ 
    2. Or navigate the County web site:
      1. http://co.laplata.co.us
      2. then click on EServices 
      3. and look for New ArcGIS Server Map Service - 
      4. Click the link to get to the GIS portal
  2. Near the top, type your address into the "Search Here" box. When you start typing the numbers it should open a box with lots of addresses. Click yours and then the magnifying glass to zoom to your parcel. 
  3. Look for a window just below the search box and click on the "Maps" button
  4. Click on the "Custom Map Theme" and a dropdown opens with some options
    1. FEMA Floodplain is your best option here
      1. Red is floodway meaning highest velocities in the floodplain
      2. Blue is 100 Year floodplain 
      3. Yellow is 500 Year floodplain 
      4. Green lines are the Base Flood Elevation or BFE. These are what FEMA calculated to be the top of water during a flood

To find your property in relation to Wildfire Hazard:

  1. Go to the Colorado Wildfire Risk Assessment Portal
    1.  http://www.coloradowildfirerisk.com/
  2. Click on the Disclaimer and then the Public Viewer
  3. On the left, use the "Getting Started" box to learn the interface and what it can do
  4. Use the search function or zoom into your neighborhood
  5. Play with the "Explore Map Themes" on the left to see different topics
  6. At the bottom of the map themes is a brown box "Active Layer Description" and below that is a button for "Full Description" that details the different layers available. 
  7. Hint: Your Insurance company likely uses a map like this to determine your home's wildfire risk!

To find your property in relation to other hazards:

  1. If you already have the GIS open, skip to #4
  2. Open the County Public GIS Portal
    1. Direct right here: http://lpcgis.laplata.co.us/LaPlataSL/ 
    2. Or navigate the County web site:
      1. http://co.laplata.co.us/ 
      2. then click on EServices 
      3. and look for New ArcGIS Server Map Service - 
      4. Click the link to get to the GIS portal
  3. Near the top, type your address into the "Search Here" box. When you start typing the numbers it should open a box with lots of addresses. Click yours and then the magnifying glass to zoom to your parcel. 
  4. Look for a window just below the search box and click on the "Layers" button. When you click the button a new window opens to the left.
    1. there are lots of check boxes with little triangles next to them. 
    2. Click the triangle next to "Environment" and you will see:
      1. Geo Hazards (rock fall, debris flow, unstable slopes, etc.)
      2. K3-K4 (boundary between low and high snowfall areas)
      3. Roof Snowload/Live Load (weight your roof is to be engineered for)
      4. Soil Type (shows expansive soil among others)
      5. Geologic Type (the underlying layer or region)
  5. Click through one at a time (click the box next to the name to turn on and off) and see where your property lies. 
Be aware that some layers turn on and off depending on how far in or out you are zoomed. 

Try wikipedia for more info on geology and geo hazard types 
The USGS has a glossary as well
http://landslides.usgs.gov/learn/glossary.php

Happy Hunting!

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