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FEMA Flood Zone Change Maps, Coos County, Oregon, by Mathew A. Tilman.

FEMA (the Federal Emergency Management Agency) produces maps that show areas that have a 1 in 100
chance of being flooded in any year (the 100-year flood). These maps are made by using the historical record of
flood height and frequency, a hydrologic computer model, and the best available topographic data. The resulting
maps, called DFIRMs (Digital Flood Insurance Rate Maps), are used to determine which properties need flood
insurance.

In Coos County, the Oregon Department of Geology and Mineral Industries has updated the DFIRMs by using
new, extremely accurate topographic data collected with a laser scanning system called lidar. The new DFIRMs
much more accurately show flood zone boundaries and also allow us to measure flood depth at any point. At the
same time, the lidar data allow us to locate every building in a community and make a GIS (geographic
information systems) map that shows the exact location, elevation, zoning class, and assessed value of each
building collected from tax assessor records. Together, these new types of information can provide a very
detailed map that shows the general level of flood risk exposure for each building in a community.

This information can be used by city officials, emergency managers, property owners, lenders, and insurers to
better understand flood risk and reduce the risk from future floods.

UNDERSTANDING THE MAPS

The maps show areas expected to be flooded during a 100-year flood and highlight the differences between the
new, more accurate DFIRMs and the older DFIRMs. The expected extent of flooding is shown by one of three
colors.

diagram showing colors that indicate extent of 100-year flooding

Publication Title Scale Price Order CD-ROM
Open-File Report O-10-12 FEMA Flood Zone Change Map, City of Bandon, Coos County, Oregon 1:6,000 CD-ROM, $15. Color plot, $25.
order
Open-File Report O-10-13 FEMA Flood Zone Change Map, City of Coos Bay, Coos County, Oregon 1:12,000 CD-ROM, $15. Color plot, $25.
order
Open-File Report O-10-14 FEMA Flood Zone Change Map, City of Coquille, Coos County, Oregon 1:6,000 CD-ROM, $15. Color plot, $25.
order
Open-File Report O-10-15 FEMA Flood Zone Change Map, City of Lakeside, Coos County, Oregon 1:6,000 CD-ROM, $15. Color plot, $25.
order
Open-File Report O-10-16 FEMA Flood Zone Change Map, City of Myrtle Point, Coos County, Oregon 1:6,000 CD-ROM, $15. Color plot, $25.
order
Open-File Report O-10-17 FEMA Flood Zone Change Map, City of North Bend, Coos County, Oregon 1:6,000 CD-ROM, $15. Color plot, $25.
order
Open-File Report O-10-18 FEMA Flood Zone Change Map, City of Powers, Coos County, Oregon 1:6,000 CD-ROM, $15. Color plot, $25.
order

Each publication CD-ROM includes:

Also see companion publications One-Percent Annual Flood Hazard and Exposure Risk Maps, Coos County, Oregon and the Coos County Flood and Natural Hazards Web Tool.

 

O-10-12, Bandon, actual size 36 x 52 inches:

preview image: O-10-12, FEMA Flood Zone Change Map, City of Bandon, Coos County, Oregon

 

O-10-13, Coos Bay, actual size 48 x 36 inches:

preview image: O-10-13, FEMA Flood Zone Change Map, City of Coos Bay, Coos County, Oregon

 

O-10-14, Coquille, actual size 36 x 41 inches:

preview image: O-10-14, FEMA Flood Zone Change Map, City of Coquille, Coos County, Oregon

 

O-10-15, Lakeside, actual size 36 x 40 inches:

preview image: O-10-15, FEMA Flood Zone Change Map, City of Lakeside, Coos County, Oregon

 

O-10-16, Myrtle Point, actual size 36 x 39 inches:

preview image: O-10-16, FEMA Flood Zone Change Map, City of Myrtle Point, Coos County, Oregon

 

O-10-17, North Bend, actual size 36 x 43 inches:

preview image: O-10-17, FEMA Flood Zone Change Map, City of North Bend, Coos County, Oregon

 

O-10-18, Powers, actual size 27 x 33 inches:

preview image: O-10-18, FEMA Flood Zone Change Map, City of Powers, Coos County, Oregon