Introduction

To manage groundwater, it is important to know its depth below the surface. This information can be used to determine the amount of groundwater that can safely be withdrawn for use. From the data provided by monitoring, local water managers can prevent wells from going dry and prevent the movement of poor quality groundwater into an aquifer.

Data Collection & Management

DWR's Northern District and its cooperators monitor groundwater levels in over 1,000 wells in Northern California. These measurements are made twice a year: once in spring, when levels are highest, and once in fall, when levels are lowest. In some areas, groundwater levels are measured quarterly. The Northern District maintains an electronic database of groundwater level measurements for Northern California. The database contains over 100,000 individual groundwater level measurements, some dating back to the early 1920's. These data are available in printed reports or in electronic form, by groundwater basin or through a map interface.

Groundwater Level Monitoring Reports

2009

Groundwater Change Report Spring 2006 to Spring 2009-Sacramento Valley and Redding Basins

Plate 1 - Spring 2006 to Spring 2009 GWE Change in Wells Up to 200 ft in depth.pdf

Plate 2 - Spring 2006 to Spring 2009 GWE Change in Wells From 200 to 600 ft in depth.pdf

Plate 3 - Spring 2006 to Spring 2009 GWE Change in Wells Over 600 ft in depth.pdf

Plate 4 - Spring 2006 to Spring 2009 GWE Change in Observation Wells.pdf

Groundwater Change Report Spring 2008 to Spring 2009 Sacramento Valley and Redding Basins.pdf

Plate 1 - Spring 2008 to Spring 2009 - GWE Change in Wells Up to 200 ft in Depth.pdf

Plate 2 - Spring 2008 to Spring 2009 - GWE Change in Wells from 200 to 600 ft in Depth.pdf

Plate 3 - Spring 2008 to Spring 2009 - GWE Change in Wells Over 600 ft in Depth.pdf

Plate 4 - Spring 2008 to Spring 2009 - GWE Change in Dedicated Observation Wells.pdf

2008

Groundwater Change Report Summer 2007 to Summer 2008 Sacramento Valley and Redding Basins.pdf

Plate 1 - Summer 2007 to Summer 2008 GWE Change in Wells Up to 200 ft. in Depth.pdf

Plate 2 - Summer 2007 to Summer 2008 - GWE Change in Wells from 200 to 600 ft. in Depth.pdf

Plate 3 - Summer 2007 to Summer 2008 - GWE Change in Wells Over 600 ft.in Depth.pdf

Plate 4 - Summer 2007 to Summer 2008 - GWE Change Map in Observation Wells.pdf

Groundwater Change Report Fall 2007 to Fall 2008 - Sacramento Valley and Redding Basins.pdf

Plate 1 - Fall 2007 to Fall 2008 - GWE Change in Wells Up to 200 ft. in Depth.pdf

Plate 2 - Fall 2007 to Fall 2008 - GWE Change in Wells from 200 to 600 ft. in Depth.pdf

Plate 3 - Fall 2007 to Fall 2008 - GWE Change in Wells Over 600 ft in Depth.pdf

Plate 4 - Fall 2007 to Fall 2008 - GWE Change Map in Observation Wells.pdf

Sacramento Valley Contour Maps

2008

Spring 2008 Contours

Spring 2008 Contours with Water Districts

Spring 2007 to Spring 2008 Change Contours

Spring 2007 to Spring 2008 Change Contours with Water Districts

Spring 2008 to Summer 2008 Change Contours

Spring 2008 to Summer 2008 Change Contours with Water Districts

Summer 2008 Contours

Summer 2008 Contours with Water Districts

Fall 2008 Contours

Fall 2008 Contours with Water Districts

2007

Spring 2007 Contours

Spring 2007 Contours with Water Districts

Spring 2007 to Summer 2007 Change Contours

Spring 2007 to Summer 2007 Change Contours with Water Districts

Summer 2007 Contours

Summer 2007 Contours with Water Districts

Fall 2007 Contours

Fall 2007 Contours with Water Districts

2006

Spring 2006 Contours

Spring 2006 Contours with Water Districts

Spring 2006 to Summer 2006 Change Contours

Spring 2006 to Summer 2006 Change Contours with Water Districts

Summer 2006 Contours

Summer 2006 Contours with Water Districts

Sacramento Valley Well Depth Summary Maps

Well depth summary maps have been created that show the approximate depth to water using groundwater contour lines. These maps also show Well Completion Report data that show the minimum, maximum, and average well depths per section for Butte, Colusa, Glenn, and Tehama counties. Additional maps that show the number of wells and well type per section can be accessed by clicking on the Well Completion Report link.

Butte County

Plate 1 - Butte County Domestic Well Depth Summary with Depth to Groundwater Contours for Wells Screened Less Than 150 feet in Depth.

Plate 2 - Butte County Large Production Well Depth Summary with Depth to Groundwater Contours for Wells Screened Greater Than 150 feet in Depth.

Colusa County

Plate 1 - Colusa County Domestic Well Depth Summary with Depth to Groundwater Contours for Wells Screened Less Than 150 feet in Depth.

Plate 2 - Colusa County Large Production Well Depth Summary with Depth to Groundwater Contours for Wells Screened Greater Than 150 feet in Depth.

Glenn County

Plate 1 - Glenn County Domestic Well Depth Summary with Depth to Groundwater Contours for Wells Screened Less Than 150 feet in Depth.

Plate 2 - Glenn County Large Production Well Depth Summary with Depth to Groundwater Contours for Wells Screened Greater Than 150 feet in Depth.

Tehama County

Plate 1 - Tehama County Domestic Well Depth Summary with Depth to Groundwater Contours for Wells Screened Less Than 150 feet in Depth.

Plate 2-TEHIRRWellCnt_MinMaxAve_12_31_08_DeepDTW3.pdfPlate 2 - Tehama County Large Production Well Depth Summary with Depth to Groundwater Contours for Wells Screened Greater Than 150 feet in Depth.