Real & Present Threats

Sitting squarely along the Cascadia Subduction Zone, the City of Newport has always faced the risk of an earthquake. But recently, a team of international researchers, including some from Oregon State University, has determined that "the odds of a big Cascadia earthquake happening in the next fifty years are roughly one in three. The odds of the very big one are roughly one in ten."*

*The New Yorker, July 20, 2015

A) Cascadia Subduction Zone ? The CSZ "megathrust" fault is a 620-mile-long dipping fault that stretches from Northern Vancouver Island to Cape Mendicino, California. It separates the Juan de Fuca and North America plates.


B) Crustal Faults - According to the Pacific Northwest Seismic Network, "Crustal faults are shallow earthquakes in Cascadia, with depths no greater than about 35km, caused by the rupture of faults within the North American Plate."

USGS 2014 National Seismic Hazard Mapping Parameters for Faults within 62 miles (100 km) of the Big Creek Dams

Fault Name Maximum Magnitude Distance (miles)
Yaquina Faults 6.1 1.9
Waldport Fault 6.4 13.0
Stonewall Anticline 6.8 21.7
Daisy Bank Fault 7.3 28.0
Alvin Canyon Fault 7.2 32.3
Wecoma Fault 7.3 32.3
Turner and Mill Creek Faults 6.6 48.5
Happy Camp Fault 6.6 51.6

Click for larger map

Central Coast Seismic Risk Potential

A Disastrous Shake-Out

Dam failure has both immediate and long-term impacts on everyone in Newport, as well as surrounding communities. Losing the public water supply for a year is devastating for residents and visitors. But it also means that jobs would be impacted or lost; health care facilities and businesses may be unable to operate; lives could be lost. Crucial infrastructure, property and land would be at risk of being heavily disturbed or destroyed.

The economic impact of a water supply loss will only continue to grow over time.

Loss of GDP Loss of Municipal Water Revenue