Category Archives: Reports

Fall 2018 Groundwater Levels in the YCFCWCD Service area

fall 2018 gw level hydrograph

Groundwater levels are measured in the YCFCWCD 150 well network each spring and fall.  The graph above show the average groundwater level of all the wells. This fall’s 2018 levels dropped, as expected each fall. In the spring, they will recover again.  Hence the saw-tooth pattern seen in the hydrograph. In the short term, the amount of drop or recovery depends on the winter rains. If there is more rain, there is less drop and more recovery. If it is dry, groundwater levels drop more and recover less. In the long term, increased pumping from wells can overcome recharge rates and levels could fall year after year, a situation called overdraft. The activities of the YSGA hope to avoid overdraft.

To Consolidate or Coordinate? Status of the Formation of Groundwater Sustainability Agencies in California

This Report was a joint effort of the Water in the West  Program at Stanford University, the Martin Daniel Gould Center for Conflict Resolution at Stanford Law School, and the Center for Collaborative Policy at California State University Sacramento.  It discusses patterns emerging in GSA formation across the state, and identifies factors affecting decisions about whether to pursue consolidated or coordinated approaches to basin governance.  It also highlights strategies that local agencies and stakeholders may find helpful as they grapple with decisions over GSA formation.  The Yolo Subbasin is one of the eight case studies discussed in the Report.

Land Subsidence from Groundwater Use in California

Land Subsidence from Groundwater Use in California by Ludhorff and Scalmanini (April 2014).  This report confirms that land subsidence in California is not just a historical occurrence, but is an ongoing problem in many regions.  The report presents key examples of significant historical subsidence and current active occurrences of subsidence, including the impacts and costs.  The Yolo County GPS and Extensometer Subsidence Network efforts are briefly discussed in the report.

Groundwater Levels – Historical Context – data sources

DWR’s Groundwater Information Center – A good example of an anaylsis tools, where you can zoom in and see the effect at Hungry Hollow, Zamora, and Conaway, etc.

https://gis.water.ca.gov/app/gicima/  (But unfortunately, the Cities’ well data was prohibited to be included until recently, so the results need to consider
that.)

 

http://wrid.facilitiesmap.com/ has raw groundwater data for Yolo County. Good for engineers, probably not what most people want.

 

A great regional analysis of long term trends in groundwater use and status is here:
http://www.norcalwater.org/groundwater-assessment/