Well, I am stuck in the 1924 drought era. The drought placed a severe strain on Great Western Power’s hydro-electric operations, though company officials assured its customers there would be no power outages. To maximize the water flow out of Lake Almanor, it was necessary to dredge channels in the lake to its outtake.
In December 1924 Great Western Power announced its intentions to raise the dam at Lake Almanor by forty-five feet. This would double the size of the lake, wherein once completed would be one of the largest reservoirs in North America at that time. The enlargement was necessary not only to protect it from future droughts, but to facilitate additional powerhouses.
Lake Almanor was raised again in the 70’s, I believe.