Officials in B.C. say a mudslide that destroyed about a half-dozen homes was caused by heavy rains and the failure of an embankment holding back a man-made irrigation lake.

A wall of mud, water and debris tore down a mountainside at about 2:20 p.m. PT on Sunday near Testalinden Creek, just south of Oliver, B.C., destroying as many as seven homes in the South Okanagan community.

Fortunately, everyone managed to make it out safely, but the debris wiped out several orchards and vineyards along with homes and other buildings.

Some of the residents have said the bills for the damage will run into the millions of dollars, but now that the slide has been blamed on human causes, it will be much easier for them to recover their losses through insurance claims.

Officials say they are trying to determine who owns the water licence for the lake where the slide is believed to have originated and who is responsible for the embankment's maintenance.

Evacuation expanded

RCMP Corp. Dan Moskaluk also confirmed the evacuation area has grown from 26 houses to 30, affecting more than 50 people, as officials remain uncertain how stable — or unstable — the slide area remains.

About two-thirds of the water has been drained from the lake on the mountain above the homes, but authorities said they don't know how settled the soil is or if another landslide could come down.

Staff from the ministries of transportation and environment and the Provincial Emergency Program are busy trying to figure out how to clean up the damage.

Meanwhile, Highway 97 remains closed in both directions, with short detours around the slide, as officials prepare to clean the debris off the road.