Westlands is able to improve overall supply reliability while minimizing total water supply costs by integrating local groundwater resources into Westlands’ comprehensive water supply system through the Groundwater Management Program and conjunctive use planning procedures.
Through the Groundwater Management Program, Westlands installs or acquires title to groundwater pumps and integrates them into its comprehensive water supply system. The program provides groundwater pumping from these Westlands-owned facilities by program participants. Participants must agree to transfer groundwater pumping facilities to Westlands and to operate and maintain those facilities. Participants pump groundwater according to Westlands schedules and are charged a cost-based fee for groundwater pumped.

Groundwater pumping facilities are eligible for inclusion in the program if they attain a 60 percent minimum overall plant efficiency and meet applicable safety standards. A participant must provide the result of an overall plant efficiency test that reflects the facility’s current condition. The participant must also ensure that the pumping plant and related facilities meet applicable electrical and safety codes prior to transfer to Westlands. Groundwater pumping facilities must be equipped with a Westlands-approved meter prior to transferring title of the equipment to Westlands.
Generally, Westlands regulations applicable to the ordering, delivery, and payment for water, including the Terms and Conditions of Agricultural Water Service, are applicable to participant’s pumping and use of program groundwater through transferred facilities.
Participants are billed for groundwater pumped under the program on an acre-foot basis pursuant to a water charge established by the Board of Directors. The water charge for program groundwater is based upon the Westlands’ cost of delivery and reflects a transferred facility’s pumping depth and efficiency. Westlands endeavors to structure water charges so that the average cost of energy per kWh is the same for all pumping facilities.
To access more details and enroll in this program, please view the Groundwater Management Program Application.
Temporary Diversions
Not all lands are served by the District’s permanent distribution system. In some areas, growers have installed their own distribution systems to deliver water from the San Luis Canal to their fields. Click through for additional detail regarding Westlands’ temporary diversions system.
Groundwater Management Reports
Westlands maintains a historical record of groundwater management program reports. Please click through to view detailed information covering 1993 – Present.
Aquifer Groundwater Maps
Water Surface Elevation
2015 Unconfined Aquifer (1,378 Kb PDF)
2015 Confined Aquifer (1,756 Kb PDF)
2014 Unconfined Aquifer (1,566 Kb PDF)
2014 Confined Aquifer (1,823 Kb PDF)
2013 Unconfined Aquifer (974 Kb PDF)
2013 Confined Aquifer (1,145 Kb PDF)
2012 Unconfined Aquifer (949 Kb PDF)
2012 Confined Aquifer (949 Kb PDF)
2011 Unconfined Aquifer (789 Kb PDF)
2011 Confined Aquifer (990 Kb PDF)
2010 Unconfined Aquifer (374 Kb PDF)
2010 Confined Aquifer (1,069 Kb PDF)
2009 Unconfined Aquifer (770 Kb PDF)
2009 Confined Aquifer (991 Kb PDF)
2008 Unconfined Aquifer (649 Kb PDF)
2008 Confined Aquifer (975 Kb PDF)
2007 Unconfined Aquifer (679 Kb PDF)
2007 Confined Aquifer (813 Kb PDF)
2006 Unconfined Aquifer (739 Kb PDF)
2006 Confined Aquifer (719 Kb PDF)
2005 Unconfined Aquifer (423 Kb PDF)
2005 Confined Aquifer (700 Kb PDF)
2004 Unconfined Aquifer (504 Kb PDF)
2004 Confined Aquifer (504 Kb PDF)
2003 Unconfined Aquifer (393 Kb PDF)
2003 Confined Aquifer (413 Kb PDF)
2002 Unconfined Aquifer (458 Kb PDF)
2002 Confined Aquifer (796 Kb PDF)
2001 Unconfined Aquifer (372 Kb PDF)
2001 Confined Aquifer (520 Kb PDF)
2000 Unconfined Aquifer (409 Kb PDF)
2000 Confined Aquifer (409 Kb PDF)
1999 Unconfined Aquifer (357 Kb PDF)
1999 Confined Aquifer (357 Kb PDF)
1998 Confined Aquifer (359 Kb PDF)
1997 Unconfined Aquifer (374 Kb PDF)
1997 Confined Aquifer (374 Kb PDF)
1996 Unconfined Aquifer (413 Kb PDF)
1996 Confined Aquifer (354 Kb PDF)
1995 Unconfined Aquifer (347 Kb PDF)
1995 Confined Aquifer (347 Kb PDF)
1994 Unconfined Aquifer (354 Kb PDF)
1994 Confined Aquifer (374 Kb PDF)
1993 Unconfined Aquifer (371 Kb PDF)
1993 Confined Aquifer (371 Kb PDF)
Depth to Water Surface
2015 Unconfined Aquifer (1,402 Kb PDF)
2015 Confined Aquifer (1,770 Kb PDF)
2014 Unconfined Aquifer (1,549 Kb PDF)
2014 Confined Aquifer (1,867 Kb PDF)
2013 Confined Aquifer (1,186 Kb PDF)
2012 Confined Aquifer (1,103 Kb PDF)
2012 Unconfined Aquifer (745 Kb PDF)
2011 Unconfined Aquifer (730 Kb PDF)
2011 Confined Aquifer (1,059 Kb PDF)
2010 Unconfined Aquifer (776 Kb PDF)
2010 Confined Aquifer (1,110 Kb PDF)
2009 Unconfined Aquifer (802 Kb PDF)
2009 Confined Aquifer (649 Kb PDF)
2008 Unconfined Aquifer (692 Kb PDF)
2008 Confined Aquifer (1,017 Kb PDF)
2007 Unconfined Aquifer (952 Kb PDF)
2007 Confined Aquifer (952 Kb PDF)
2006 Unconfined Aquifer (728 Kb PDF)
2006 Confined Aquifer (734 Kb PDF)
2005 Unconfined Aquifer (428 Kb PDF)
2005 Confined Aquifer (483 Kb PDF)
2004 Unconfined Aquifer (450 Kb PDF)
2004 Confined Aquifer (533 Kb PDF)
2003 Unconfined Aquifer (398 Kb PDF)
2003 Confined Aquifer (427 Kb PDF)
2002 Unconfined Aquifer (484 Kb PDF)
2002 Confined Aquifer (877 Kb PDF)
2001 Unconfined Aquifer (425 Kb PDF)
2001 Confined Aquifer (462 Kb PDF)
2000 Unconfined Aquifer (405 Kb PDF)
2000 Confined Aquifer (448 Kb PDF)
1999 Unconfined Aquifer (364 Kb PDF)
1999 Confined Aquifer (361 Kb PDF)
1998 Unconfined Aquifer (349 Kb PDF)
1998 Confined Aquifer (359 Kb PDF)
1997 Unconfined Aquifer (346 Kb PDF)
1997 Confined Aquifer (413 Kb PDF)
1996 Unconfined Aquifer (357 Kb PDF)
1996 Confined Aquifer (360 Kb PDF)
1995 Unconfined Aquifer (354 Kb PDF)
1995 Confined Aquifer (357 Kb PDF)
1994 Unconfined Aquifer (352 Kb PDF)
1994 Confined Aquifer (373 Kb PDF)
1993 Unconfined Aquifer (340 Kb PDF)
1993 Confined Aquifer (360 Kb PDF)
Shallow Groundwater Maps
Water Surface Elevation
April 2016 (2,055 Kb PDF)
October 2015 (1,983 Kb PDF)
April 2015 (1,533 Kb PDF)
October 2014 (1,592 Kb PDF)
April 2013 (837 Kb PDF)
October 2012 (1,007 Kb PDF)
October 2011 (720 Kb PDF)
April 2010 (1,102 Kb PDF)
October 2009 (1,036 Kb PDF)
April 2009 (1,004 Kb PDF)
October 2008 (1066 Kb PDF)
April 2008 (1,050 Kb PDF)
October 2007 (631 Kb PDF)
April 2007 (1,024 Kb PDF)
October 2006 (1,027 Kb PDF)
April 2006 (1,086 Kb PDF)
October 2005 (631 Kb PDF)
April 2005 (644 Kb PDF)
April 2004 (543 Kb PDF)
October 2004 (725 Kb PDF)
April 2003 (483 Kb PDF)
October 2003 (469 Kb PDF)
April 2002 (414 Kb PDF)
October 2002 (400 Kb PDF)
April 20011/2/2014 (395 Kb PDF)
October 20011/2/2014 (468 Kb PDF)
April 2000 (347 Kb PDF)
October 2000 (514 Kb PDF)
April 1999 (607 Kb PDF)
October 1999 (419 Kb PDF)
April 1998 (445 Kb PDF)
October 1998 (257 Kb PDF)
April 1997 (418 Kb PDF)
October 1997 (423 Kb PDF)
April 1996 (378 Kb PDF)
October 1996 (424 Kb PDF)
April 1995 (438 Kb PDF)
October 1995 (427 Kb PDF)
April 1994 (501 Kb PDF)
October 1994 (412 Kb PDF)
April 1993 (462 Kb PDF)
October 1993 (406 Kb PDF)
Depth to Water Surface
April 2017 (1,437 Kb PDF)
October 2016 (1,375 Kb PDF)
April 2016 (1,445 Kb PDF)
October 2015 (1,434 Kb PDF)
April 2015 (1,841 Kb PDF)
October 2014 (2,053 Kb PDF)
April 2014 (893 Kb PDF)
October 2013 (829 Kb PDF)
April 2013 (773 Kb PDF)
October 2012 (870 Kb PDF)
April 2012 (865 Kb PDF)
October 2011 (846 Kb PDF)
April 2011 (908 Kb PDf)
October 2010 (852 Kb PDF)
April 2010 (886 Kb PDF)
October 2009 (853 Kb PDF)
April 2009 (825 Kb PDF)
October 2008 (807 Kb PDF)
April 2008 (865 Kb PDF)
October 2007 (529 Kb PDF)
April 2007 (887 Kb PDF)
October 2006 (769 Kb PDF)
April 2006 (571 Kb PDF)
October 2005 (523 Kb PDF)
April 2005 (630 Kb PDF)
April 2004 (805 Kb PDF)
October 2004 (529 Kb PDF)
April 20031/2/2014 (423 Kb PDF)
October 20031/2/2014 (438 Kb PDF)
April 2002 (413 Kb PDF)
October 2002 (440 Kb PDF)
April 2001 (418 Kb PDF)
October 2001 (440 Kb PDF)
April 2000 (469 Kb PDF)
October 2000 (445 Kb PDF)
April 1999 (440 Kb DWF)
October 1999 (405 Kb PDF)
April 1998 (365 Kb PDF)
October 1998 (512 Kb PDF)
April 1997 (392 Kb PDF)
October 1997 (392 Kb PDF)
April 1996 (406 Kb PDF)
October 1996 (402 Kb PDF)
April 1995 (393 Kb PDF)
October 1995 (406 Kb PDF)
April 1994 (401 Kb PDF)
October 1994 (441 Kb PDF)
April 1993 (415 Kb PDF)
October 1993 (440 Kb PDF)