A damaged earthen dam holding back a lake swollen by runoff from the remnants of a tropical storm was still at risk of failing Thursday and inundating a small Native American village near the U.S.-Mexico border, officials said.
The dam suffered “some erosional damage” when it was overtopped by water as the lake behind it grew in size because of heavy rains that started Tuesday, the National Weather Service said in a statement that extended a flash flood warning until Thursday afternoon for the village of Ali Chuk on the Tohono O’odham Indian Nation reservation.
Tribal officials said in a statement late Wednesday that water levels behind the dam were receding but that its structural integrity was still “a major concern” and that the tribe was working to put together an engineering team to inspect the dam.
Most of Ali Chuk’s residents have been evacuated or left on their own but tribal officials said Wednesday that a few refused to leave.
Elsewhere, part of a northern Arizona highway was closed Thursday because of storm damage after the remnants of Tropical Storm Rosa dumped rain throughout the state.
The northbound lanes of U.S. 89 were closed in the small community of Cameron and southbound lanes were closed at a highway junction north of Cameron, the Arizona Department of Transportation said in a statement.
Repairs will probably require an extended closure, meaning drivers will have to take alternative routes with much longer travel time, the department said.