City and state officials are determining if crews can safely begin repairing damage to the riverbank after a two-acre landslide collapsed into the Presumpscot River on Wednesday, prompting the City of Westbrook to go into a state of emergency.

The landslide blocked off a section of the Presumpscot River downstream from the Sappi Mill for several hours and forced the water level behind the blockage to rise up to 13 feet.

Damage assessment began Thursday and is expected to continue through Friday, the Portland Press Herald reported.

There was a large landslide along the Presumpscot River in Westbrook Wednesday, where the mayor has declared a state of emergency. Credit: CBS13

Risk of flooding subsided as the water levels started to decline throughout the afternoon after Sappi North America restricted river flow at its five dams upstream.

The water level was unusually low before the slide occurred, which helped prevent flooding on the riverbank or upstream. Immediate risk of flash flooding had passed by Thursday afternoon.

The area has a long history of landslides because of the river’s large marine or quick clay deposits — soft soil that is often found in coastal areas and can behave as a liquid if disturbed, causing landslides.

Senior Geologist with the Maine Geological Survey Lindsay Spigel referred to this as what caused the landslide but couldn’t specify exactly what triggered it, according to the Press Herald.

The state of emergency remained in effect as of Thursday. The city council is expected to hold a special meeting Monday, Sept. 21 to address the incident.