I'm not at all surprised. Last winter the Central Sierra was fairly dry. Last summer though there were some minor periods of thunderstorm activity, it was generally lower than normal. Then late September and early October had a few small fronts come through that for the most part just moistened landscapes with very little runoff. Then the past several weeks have been bone dry. I've been telling people this November was the driest I've ever experienced here in Central California. So yes most granite geology Sierra rivers are likely now near historic lows. Some high country creeks that always have flows likely just have occasional stale pools now. A large number of trout in streams have likely died back to just a few deeper such pools. Those rivers like the San Joaquin, Kings, and Kern that have significant higher areas with permanent snowfields always have somewhat greater flows at this time of year. Those larger rivers to the north where the drought has been less severe and more fall storms have visited this year are likely not close to historic lows. With their considerable slower to drain off volcanic geologies, minimal flows tend to remain higher in the fall. One can find historic monthly seasonal flow records for all our streams and rivers on the CDEC website under "unimpared river flows". ...David
http://www.davidsenesac.com