Countywide FEMA Floodplain Maps Effective February 17, 2010
Note: New Coastal Douglas County Preliminary Maps projected spring 2017
***Interactive Map Tool at bottom of page***
Principal Flood Problems
The highest stream flows in the Umpqua River basin usually occur during November through March as a result of heavy winter rains augmented by snowmelt. Most of the flooding occurs in the valley areas of the South Umpqua and Umpqua Rivers, although the tributary streams of Cow Creek, Calapooya Creek, and Elk Creek also have extensive flood plains. Most of the land subject to flooding along the South Umpqua River is below Days Creek. Because these valleys are the most densely populated and intensively developed in Douglas County, the principal flood problems occur along this stream. A flood potential also exists along the Umpqua River between Elkton and the confluence of the North and South Umpqua Rivers. In the Glendale-Azalea valley of Cow Creek, much bank erosion and channel shifting occurs during floods. default Read more...
Changes since last mapping
The detailed study area floodplain boundaries for Newton Creek, 4.2 miles of Deer Creek, 8.4 miles of the South Umpqua River, and 3.1 miles of the North Umpqua River were revised with new topographic mapping with a contour interval of 2 feet. Newton Creek floodplain boundaries were revised within the corporate limit of Roseburg. The floodplain boundaries of Deer Creek were revised from the confluence with the South Umpqua River to 4.2 miles upstream to the southeast corporate limit of Roseburg. The South Umpqua River floodplain boundaries were revised from approximately three miles downstream of the western corporate limit of Roseburg to 3,500 feet upstream of the southern corporate limit of Roseburg. The North Umpqua River floodplain boundaries were revised from approximately River Mile 6.5 upstream to River Mile 9.6.
The effective detailed study area (pre-reservoir) of Cow Creek inundated by the pool of Galesville Reservoir was replaced with an approximate "A" zone designation. The USACE provided an elevation-outflow curve for Galesville reservoir which was used to approximate the reservoir elevation for the base-flood. The A zone was delineated using 1:24,000 USGS topographic map with a contour interval of 40 feet.
The remaining floodplain boundaries were digitized from the effective FIRM and Floodway panels. Aerial photography and USGS topographic maps were used to adjust floodplain and floodway boundaries where appropriate.
A "KML" is a file that can be downloaded and opened directly in Google Earth, ArcGIS Explorer and other viewing software available on the Internet. The KML below is for the Special Flood Hazard Area (SFHA), also known as the "100-year" flood.
-Download KML -
A Flood Insurance Study (FIS) is the publication developed in conjunction with the Flood Insurance Rate Map (FIRM) and discusses the engineering methods used to develop the FIRMs. The study also contains flood profiles for studied flooding sources and can be used to determine Base Flood Elevations for some areas.
-Download County Flood Insurance Study :
Coastal area FIRMs are being updated; preliminary expected spring 2017
Snapshots around the County
Umpqua River, Special Flood Hazard Area (SFHA), looking northwest:
Note - For general information only - DO NOT use for regulatory purposes, especially for non-modernized areas: see "description" for source information and disclaimer
(hint: once in Viewer select "Basemap" in upper left corner for imagery background)