Manhattan ? The Army Corps of Engineers is spending $200 million to inject cement into the sand beneath Tuttle Creek Dam to make it able to withstand a high-magnitude earthquake.

Crews are expected to begin work in November on the Manhattan-area dam, which is just 12 miles from the Humboldt fault. The corps has become concerned that a quake with a magnitude of 5.7 or higher on the Richter scale could destroy the dam and flood much of Manhattan, endangering about 13,000 people.

Officials also worry that if the dam fails, levees downstream in Topeka and Kansas City could also break.

To date, the strongest earthquake ever recorded in Kansas occurred in 1867 in nearby Wamego. With a magnitude of 5.5 on the Richter scale, the quake caused minor damage as far as Kansas City.

The corps began studying Tuttle Creek and other dams built on sand foundations after the San Fernando Valley dam in California nearly collapsed during a quake in the 1970s. The corps later learned the dam’s sand foundation had liquefied.