Maps have NOT been modernized, still in paper format
All FEMA Floodplain Maps Effective December 22, 1998*
New county-wide digital Preliminary maps projected March 2017
Principal Flood Problems
Floods on the Silvies River may generally be classified as:(1) spring floods resulting primarily from rapid snowmelt, occasionally augmented by rainfall; (2) winter floods; and (3) thunderstorm floods. Spring floods generate both widespread and prolonged flooding of the Silvies River, accounting for most of the annual flood damage.
Flooding occurs on the Silvies River because of an inadequate natural channel capacity to contain spring flood flows. Historical and eyewitness accounts indicate that flooding from the Silvies River spreading out like a fan as it flows southerly and westerly into Malheur Lake. The flooding ranges upward from 20 to 30 miles through the swampy valley floor. During high-water periods, the area appears as a large lake.
Floods of significant size have occurred in 1897, 1904, 1921,1943, 1952, 1957 and 1964. ·The flood of 1897 is the largest known flood on the Silvies River. It occurred before any stream gages were installed. Although little historical data are available, the flood is estimated to have had a flow of approximately 9,000 cubic feet per second (cfs) and an occurrence probability of approximately once in 300 years.
There are eight distinct drainages in the foothills west of Burns and Hines; all have the potential of flooding a common floodplain between the base of the hills and the Silvies River. In addition, the gradients of its meandering ditches are very flat, thereby causing overflow along their routes.
None at this time
- 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.
- 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 KML - not available at this time
- Download County Flood Insurance Studies:
- default Harney Co FIS (2.81 MB)
- default Burns FIS (2.5 MB)
- default Hines FIS (2.12 MB)
Harney County, including the Silvies Watershed extending into Grant County, is currently being remapped as part of a FEMA Risk MAP project. Project re-scoped and new Preliminary Maps projected March 2017.
Snapshots around the County
Note - For general information only - DO NOT use for regulatory purposes, especially for non-modernized areas: see "description" for source information
(hint: once in Viewer select "Basemap" in upper left corner for imagery background)