The state is in the midst of another attempt to control the population of invasive New Zealand mud snails in Capitol Lake.
But, lowering the lake to try to freeze out the snails likely isn’t going to do the trick. Doug Myers, Director of Science for People For Puget Sound, explains why:
The very nature of Olympia, one of the springs capitals of the world, prevents lake drawdowns from being a very effective treatment for New Zealand Mud Snails. During the last freeze attempt, I walked around the lake. It was very cold, there was snow on the ground and parts of the exposed mudflats had a crust of ice on them. However, the thousands of tiny springs and seeps that continue to flow into the lake, even during drawdown provide a thermal refuge for the snails. In the end, this once a year shock may reduce the snails populations a little, but will not eliminate them or maintain them at low population levels. Daily inundation with saltwater would be a much more effective treatment, at least for the central and north basins greatly reducing the distribution of the snails to the freshest south basin. Reducing the aerial extent of the infestation would also greatly reduce the likelihood of birds spreading the snails to adjacent freshwater systems like Black Lake.