Local Flood Hazard
- Updated on Tuesday, October 02, 2012 October 02, 2012
Preparing for the Next Flood
Albany was settled near the confluence of the Calapooia and Willamette rivers. Upstream, the Willamette River watershed drains approximately 4,840 square miles of mostly mountainous timberland. Development in the watershed can increase the magnitude and frequency of flooding. As fields and forests are replaced by "impervious surfaces" (such as pavement and buildings), the development changes the way the water is stored and how it moves through the watershed.
Causes of Flooding in Albany
Albany is subject to two types of flooding:
- Riverine flooding is the overbank flooding of rivers and streams. In Albany, these include the Willamette and Calapooia rivers; Oak, Periwinkle, Cox, Burkhart, and Truax creeks, and the Santiam-Albany Canal.
- Urban flooding results from an unusual and rapid accumulation of storm water that temporarily exceeds the capacity of the local storm water drainage system.
Flooding of streams and rivers in Albany generally results from large winter storms from the Pacific Ocean. When heavy rainfall comes at the same time as snow-melt runoff, winter storms can result in simultaneous flooding on all rivers and streams in an affected area. Historically, most major floods in Albany have occurred December, January and February, although flooding in other months is possible.
Flood records for the City of Albany indicate no regular pattern in which floods occur. Heavy rains that saturate the ground and fill rivers and creeks coupled with warming weather that melts heavy mountain snow created the major flooding that Albany has seen over the last 150 years.
The last major floods since the dams were built on rivers upstream took place in 1964 and 1996. The February 1996 flood was the highest in recent memory but was considered significantly less than a "100-year flood," which is a flood that has a 1 in 100 (1%) chance of happening in any given year. The Christmas Flood of 1964 caused $157 million in damage, and 20 Oregonians lost their lives.
County records dating back to the mid-1800s indicate that the Willamette River has caused significant flooding to the County at least seven times. The record flood of 1861 had almost three times the volume of water in the Willamette River as measured at the Albany gauge. The 1964 flood would have rivaled the 1861 flood without the flood controlled dams.
If you are in the floodplain, odds are that someday your property will be damaged. Even if you don't live in a floodplain, knowing what to do (and not to do) in a flood can be life-saving.