Modernizing Oregon’s Dam Safety Statutes By Racquel Rancier
Astoria’s Bear Creek Dam is drilled through as part of a seismic analysis. The analysis showed that the dam is unlikely to fail in a Cascadia Subduction Zone earthquake.
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focus on improving the safety of dams under its jurisdiction, recognizing that actions must be taken to address dam safety deficiencies in order to prevent the loss of life and damage to property from a dam failure and to preserve the many benefits that dams provide for our communities and economy. The Oregon Water Resources Department (WRD) is the state agency charged with overseeing the safety of approximately 950 dams in Oregon that store water for agriculture, cities, industry, recreation, fisheries, and other purposes. Of these dams, 76 are rated as high hazard, meaning that the loss of human life would be expected should the dam fail, while another 151 are rated significant hazard, meaning failure is likely to result in damage to property or infrastructure, but not the loss of life. The hazard rating reflects the expected results of failure, not the condition of the dam.
PHOTOS COURTESY OF THE OREGON WATER RESOURCES DEPARTMENT.
n 1928, the St. Francis Dam in California failed, resulting in the loss of hundreds of lives and the passage of dam safety laws in several states, including Oregon. Over the years, however, the resources dedicated to dam safety have been limited, and challenges in ensuring their safety remain. Engineering standards have evolved over time, as has our understanding of seismic and flood risks, demanding new actions and programs. These challenges are compounded by the fact that dams are aging, with some showing signs of degradation or requiring urgent repairs. These challenges are not unique to Oregon, and in the past 5 years, the failure of over 100 dams in North and South Carolina during extreme flooding and the safety incident at California’s Oroville Dam have demonstrated their urgency. Recently, the State of Oregon has increased its
