The situation remained critical at the lake and in other areas of the canton such as Lake Thun and the Aare River, as well as Lake Neuchâtel, where water levels are also dangerously high, the ATS news agency reported.
The canton of Bern’s water management office raised the flooding alert level from three to four (on a scale with five as a maximum) on Tuesday.
At 8am the same day cantonal authorities banned boating on the lake because of the high water levels of the lake.
Meantime, Yverdon-les-Bains and Grandson in the canton of Vaud faced a threat from the rising level of Lake Neuchâtel.
Weather forecasters predicted relief from the steady rain that has fallen on Western Switzerland since Friday, triggering landslides and flooding in the cantons of Vaud and Valais and swamping areas of Geneva, where the Arve River rose to its highest level in at least 80 years.
Bridges across the Arve reopened to traffic on Tuesday after being briefly closed because of flooding concerns.
Rail traffic returned to normal late Tuesday on the line between Lausanne and Vevey following a landslide that disrupted train schedules.
Water levels also dropped in rivers flowing through the Valais communities of Monthey and Saint Gingolph, where surging water earlier left rocks and debris in the streets, damaging buildings.
In Monthey, where residents in part of the town were forced to evacuate over the weekend, the Vièze River has dropped by a metre from its highest levels, broadcaster RTS reported.
However, access to Les Crosets, a ski resort village in the Portes du Soleil area, remained cut on Wednesday because of the closure of a road threatened by landslides, the broadcaster said.
Sunny and dry periods were forecast for the region later Wednesday and Thursday, although rain is expected to return on Friday.