Indicators of a drought ending in northern California

sacramento-weir-flowing-january-2017

Sacramento Weir flowing into Yolo Bypass, January 2017, for first time since December 2005, photo: Jay Lund

Jay Lund

Droughts are common in California, a large, generally dry, and hydrologically complex place.  So it is hard to rely on a single index of the end or beginning of a drought.  A single storm is rarely enough to end a drought in California, especially a long drought like the one that seems to be mostly ending now.  Regular hydrologic statistics can be used as indicators of drought, but these do not do justice to how droughts actually end (or begin).

Here are some less formal indicators that the current drought is ending, although in some ways this drought and its impacts will endure for decades to come.

  • Guerneville on the Russian River has flooded. This is usually about the first town to flood in California. Guerneville floods so often that I wonder how it is still there or has not become just a summer camp!
  • Van Sickle Island in the Delta floods. Usually this is the first Delta island to flood.  It has some of the Delta’s lowest and weakest levees, but has mostly ducks for residents.
  • Most reservoirs are full, or at least filled to levels where they are kept partially empty for possible floods.
  • Weirs and bypasses are actively draining the Sacramento Valley. The mighty Fremont Weir has taken control of the Sacramento River, flowing at almost 200,000 cfs.  The Sacramento Weir, completed in 1916, is open for the first time since December 2005.  Awesome!
  • Skiing exists, and seems relatively good. Count the skis racks on cars heading East on Friday afternoons, or heading West at the end of the weekend.  Count the conversations about ski lift lines and ticket price strategies at work on weekdays.
  • My roof leaks and the kids scoff at raking wet leaves. We all have our own personal drought indicators.
  • I feel a need to remind people how dangerous flowing water and floods are.  Don’t wade or drive into moving water, even if it is shallow.  Be careful.

California must now deal with the aftermath of the drought and preparing for the next one, even as some parts of California still suffer from the drought and some areas worry about flooding.  Hopefully southern California, especially poor Lake Cachuma, benefits from storms in the weeks to come.  We live in a complex place.  But it works better if we work at it.

So, back to my roof and putting my kids to work.  Another storm is coming later this week.

Fremont Weir, several feet under water, taking water from Feather and Sacramento Rivers into Yolo Bypass, January 2017. Flow about 180,000 cfs over 2 miles of weir.  Don’t enter if you value your life – very dangerous.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis.  He came to California just after the 1986 flood and in time for the 1988-92 drought.

Further reading

Sacramento River Flood Control Project Weirs and Flood Relief Structures, by California Department of Water Resources, 2010.

Lund, J.R., “Flood Management in California,” Water, Vol. 4, pp. 157-169; doi:10.3390/w4010157, 2012.

Suddeth, R. and J. Lund “Multi-Purpose Optimization of Reconciliation Ecology for an Engineered Floodplain – Yolo Bypass, California,” San Francisco Estuary and Watershed Science, Volume 14, Issue 1, 2016.