Countywide FEMA Floodplain Maps Effective June 2, 1999
Upper Willamette River and some tributaries part of a Physical Map Revision, preliminary maps projected possibly 2017. Coastal portion of Risk MAP preliminary FIRMs projected spring 2017.
***Interactive Map Tool at bottom of page***
Principal Flood Problems
Major flooding usually occurs in Lane County during December and January as a result of heavy rains combining with increased snowmelt. Normal spring snowmelt usually causes only minor flooding.
Along the coast, high spring tides combine with surges produced by strong winds from winter storms, causing coastal flooding. Storms that produce coastal flooding often bring heavy rain, producing high river flows. These flows are held back at the mouth of the stream by high ocean levels, thus increasing flood hazards.
During periods of heavy flooding, vegetation in the floodplains may be uprooted, often blocking culverts and bridge openings. The logging industry compounds this problem by storing logs in the rivers. Logs have been known to breech private levees and cause extensive damage.
Several major floods have occurred in Lane County. The largest of these was the December 1964 flood. Other major floods occurred in 1861, 1890, 1945, and 1956. All of these floods occurred during winter, lasting several days, and were caused by the combination of snowmelt, heavy rainfall, and saturated soils. Flooding has been altered significantly since the construction by the USACE of several reservoirs. default Read more...
Changes since last mapping
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 (updated Nov. 2016) -Lane Co SFHA (3.6 MB)
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:
Partial county mapping includes redelineation of approx. and detailed SFHAs to new county-provided topo for Amazon R., Mohawk R., Middle Fork Willamette R., Coast Fork, Row R., and Mckenzie R.; Non-levee area preliminary maps possible release summer 2015; New Lane coastal mapping beginning; preliminary maps expected 2015.
Snapshots around the County
NFIP Policies in Florence area -
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)