(Click on the above image for a video)
Otter Lake in Tulameen rose another 12 inches (30 centimetres) overnight, and may continue to rise unless colder weather moves in.
The lake has risen more than three feet in two days because of melting snow pack and heavy rain.
The forecast for this weekend is sunny with a high of 17 C.
"The homes are on a flood plain and have been prone [to flooding] before, but this came on very rapidly and totally unexpected," said Dan Ashton, Regional District Okanagan-Similkameen spokesman.
"The greatest concern right now is possible contamination between wells and septic tanks,"
Tulameen residents shouldn't drink the water, and should boil it before use. Bottled water is available for drinking.
Another seven houses have been affected, bringing the total to 81 out of 272 houses that have been flooded are nearly flooded.
An evacuation alert was issued Tuesday.
Some residents are staying in Princeton with friends or at a hotel. A registration centre is still open in Princeton. Residents are asked to check in with the fire hall prior to leaving the area.
Photos show houses flooded after Otter Lake rose three feet overnight Wednesday.