The recent Napa earthquake surprised only a few people in California wine country, but there may have been some nervousness about the same time in Kansas. On August 25 a little 3.0 temblor shook the ground near the southern Kansas town of Harper. No damage.
But it got the attention of some people to the north in Manhattan, Kansas. That is the home of Kansas State University and is not far from Fort Riley. The 52,000 residents of the “Little Apple” live with the Humboldt Fault, which is the most active of many fault lines that run through the state. In 1867 there was a 5.5 Richter Scale quake along the Humboldt, which is 12 miles away from Manhattan.
“There is a building standard for the kind of earthquake area we are in,” Riley County Emergency Management Director Pat Collins told a TV reporter recently. Earthquakes are included in their all-hazards mitigation planning, and the U.S. Army Corps of Engineers also pays serious attention to earthquake possibilities. In July 2010 the Corps completed a $90 million project to add 351 underground concrete stabilization walls and a series of seismic sensors to Tuttle Creek Dam. This High-Hazard Potential dam puts thousands of people at risk.
“We did come up with some evacuation plans for a catastrophic event like that,” Collins said.
But it could take anywhere from 10-24 hours to evacuate people to safety.
Tuttle Creek is a reminder that lots of states not normally associated with earthquakes need Emergency Action Plans for High-Hazard Potential dams because seismic activity can damage them and could cause failure.