Held in the cracks and crevices of soil and rock underground, groundwater can be found between 200 and 2000 feet beneath our valley and is accessed through wells. Groundwater makes up about 38 percent of the total water supply in California and, in the Santa Clarita Valley, it is half of our water supply during an average year.

Our local groundwater comes from two sources:

  • The Alluvium Aquifer - which generally underlies the Santa Clara River and its tributaries to maximum depths of about 200 feet.
  • The Saugus Formation - which underlies practically the entire Upper Santa Clara River Sub-basin area to depths of at least 2,000 feet.

 A number of wells were shut off beginning in 2019 due to the detection of certain chemicals (see PFAS for details). However ongoing investment into treatment facilities is restoring this local and affordable water source.

Aquifers and Accessing Groundwater

Geology plays an important role in the availability of groundwater. Did you know that an aquifer is not a big underground lake? Instead, permeable and porous materials such as sand, gravel and some sedimentary rocks can hold and transmit water underground, kind of like a gravelly sponge. The water can even move between voids and fractures in rocks. 

Our local groundwater is accessed through a series of wells located across SCV. You might not even realize it, but you are probably driving past them as you run errands around town.

Local Groundwater Management

Santa Clarita depends on groundwater for a portion of its annual water supply, and sustainable groundwater management is essential to a reliable and resilient water system. Good groundwater management can provide a buffer against drought and climate change and contribute to reliable water supplies regardless of weather patterns.

Click here to learn about our Groundwater Sustainability Plan