The Truckee River flows are up again through Reno, right?  So that water is going to Pryamid Lake, you’re thinking?  Of course, those giant cutthroat trout that folks try to catch at Pyramid Lake are getting the benefit of the water finally flowing in the river?

In reality, as the river comes up, the Truckee River is tapped by the Newlands Project.  The water diversion 15 miles east of Sparks at Derby Dam sends the Truckee’s increased flows of water through a canal to fill the reservoir on the Carson River.  Lahontan Reservoir stores water to be used by farmers in the Fallon area.  Lahontan sits outside of the Truckee River watershed and Truckee River water only reaches it through the man-made canal built 110 years ago.

The graphic which follows shows what happened between November 1st and today, December 11, 2014.  As the river flows increased starting around November 28, more and more water was taken out of the Truckee River and sent through the canal to Lahontan Reservoir.  So instead of 350 CFS flowing into Pyramid Lake today, the majority of the water is diverted to Lahontan.  Pyramid Lake receives just about 110 CFS while about 240 CFS heads to the reservoir (December 11, 2014).  [Click on the graph to see a larger version.]  No wonder that Pyramid Lake has fallen more than 25 feet during the past 14 year drought.  [See post “Just 14 years ago”]

Graphic of Truckee River flows: Pyramid Lake doesn’t benefit from increasing flows in River

The blue symbols represent Truckee River flows just below Reno at Vista, the yellow symbols flows near Pyramid Lake, and the red symbols flows in the diversion canal.  (Diversions from the Truckee River have taken the lion’s share of water during the 3 year drought.)

So rivers do flow on – except when they aren’t allowed to.