If you’ve seen the lake in the last few weeks you would have noticed that the water level is dramatically lowered from it’s normal depth. This is done every three years to allow home owners along the lake to repair sea walls and boat houses. It also allows the many members of lake easements to do the same types of repairs on the easement property.
Dropping the water level was done by allowing water out on November 11th via the spill way at the East end of the lake. On January 2nd the lake will be allowed to naturally refill with rain and the water that feeds the lake at the Tualatin River. It will take about two months to refill to its normal level. So it will be back to normal in plenty of time for warm weather recreation.
I’ve seen this done many, many times over the years. The explanation is always that it allows repair of sea walls, etc. I also am of the opinion that it improves the water quality.
In any case, it is a bit of an unusual sight with a reasonable explanation.