The Sierra snowpack is melting quickly, sending water flowing into nearby rivers and reservoirs. This is the normal cycle for snowmelt but research by the California Department of Water Resources found now it’s happening sooner in the season. This means there’s a larger gap between peak runoff and peak demand.
Snow in the Sierra is a great resource for water during the dry late spring and summer months. With a nice, steady snowmelt reservoirs get replenished as water is released to ease the dry conditions. Problems arise though when the peak runoff is well ahead of peak demand. This is the case again this year. A couple of warm weather stretches in March and April started the snowmelt earlier than normal. This led to earlier runoff into area reservoirs and forced DWR to release some of the water due to flood control regulations.
There’s still snow to melt, but the statewide average snowpack is only 51 percent of normal for this time of year. Looking at inflow charts of Folsom and Shasta, it appears the peak has or is currently occurring. For Folsom this is ahead of schedule, but for Shasta the inflow is close to normal.
DWR regulators now have to look at a steady distribution of this water for the next several months until the 2016-17 rainy season begins in November. This is an increasingly difficult task as the time span between peak runoff and peak demand widens.
Warmer temperatures also mean nearby rivers will be filling with fresh snowmelt. The water will be swift and cold. The American River is about 60° and the Sacramento River is about 67 degrees.