The swollen Saco River swirls against exterior walls Monday at The Mill at Saco Falls, a 66-unit apartment complex in Biddeford that opened in November. City officials say the river breached a wall that keeps it away from the complex, but water had not entered any of the apartments as of Monday afternoon.

Concerns about the rising water and strong currents prompted one of the building’s owners, Nathan Szanton of Portland, to temporarily relocate residents of seven apartments to a local hotel Saturday. Szanton said a construction company may be brought in this week to shore up the protective wall with sandbags weighing 1,000 to 2,000 pounds.

If the water gets into the building, power would have to be shut off, said Roby Fecteau, Biddeford’s director of code enforcement and emergency management. Engineers have been evaluating the building to make sure it remains structurally sound, he said.