InTeGrate Modules and Courses >Water Science and Society > Student Materials > 6.1 Aquifers and Properties > Regional Aquifer Systems: Examples > Central Valley/San Joaquin Valley Aquifer System
InTeGrate's Earth-focused Modules and Courses for the Undergraduate Classroom
showLearn More
These materials are part of a collection of classroom-tested modules and courses developed by InTeGrate. The materials engage students in understanding the earth system as it intertwines with key societal issues. The collection is freely available and ready to be adapted by undergraduate educators across a range of courses including: general education or majors courses in Earth-focused disciplines such as geoscience or environmental science, social science, engineering, and other sciences, as well as courses for interdisciplinary programs.
Explore the Collection »
show Download
The student materials are available for offline viewing below. Downloadable versions of the instructor materials are available from this location on the instructor materials pages. Learn more about using the different versions of InTeGrate materials »

Download a PDF of all web pages for the student materials

Download a zip file that includes all the web pages and downloadable files from the student materials

For the Instructor

These student materials complement the Water Science and Society Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.

Central Valley/San Joaquin Valley Aquifer System

The Central Valley Aquifer system of Central CA lies in a large structural basin running approximately North-South, between the Coast Ranges to the West and the Sierra Nevada mountains to the East (Figure 22). The deep elongate basin is infilled with marine and continental sediments, primarily composed of interlayered sands and clays. The basin itself is formed by tectonic processes caused by East-West extension (these are the same forces that are causing continued uplift of the major mountain chains throughout the Basin and Range province of the Southwestern US, and which are one major control on orographic precipitation patterns in that region).

The continental deposits (Figure 22, orange) comprise the main aquifer units, and range from one-half to over two miles in thickness. As is the case in the Valley and Ridge, recharge is primarily focused around the valley perimeter as runoff over the flanks of surrounding high topography infiltrates and enters the groundwater system. Groundwater flow is primarily inward, toward valley center, with a component of flow down-valley to the North, parallel to surface water flow in the San Joaquin River.

The thick sedimentary sequence has formed a vast expanse of flat topography on the natural floodplain of the San Joaquin River. This, in combination with a mild climate that allows a year-round growing season, has made the Central Valley one of the most productive and largest agricultural centers in the world. The Central Valley aquifer system is highly utilized, primarily to augment limited allocations of surface water for irrigation. Since the mid-1920's, groundwater withdrawals have generally outpaced natural recharge to the aquifer, leading to dropping water levels, irreversible aquifer compaction, and land subsidence (as will be discussed in more detail next week, in Module 6.2). Until recently, groundwater withdrawals were neither heavily monitored nor regulated. However, in the face of an ongoing multi-year drought, a new bill was signed into law in mid-September, 2014 that restricts pumping (See What to Know about California's New Groundwater Law; see also New California Groundwater Pumping Rules Signed Into Law). Shallow aquifer units in the valley are also plagued by a wide range of water quality concerns associated with irrigation and return flow of irrigation water to the aquifer via infiltration; these include leaching of selenium, boron, and other constituents from soils; salinization; and high concentrations of pesticides and fertilizers. We'll discuss all of these issues in more detail in upcoming modules about water quality and the effects of climate change.


These materials are part of a collection of classroom-tested modules and courses developed by InTeGrate. The materials engage students in understanding the earth system as it intertwines with key societal issues. The collection is freely available and ready to be adapted by undergraduate educators across a range of courses including: general education or majors courses in Earth-focused disciplines such as geoscience or environmental science, social science, engineering, and other sciences, as well as courses for interdisciplinary programs.
Explore the Collection »