Ever hear of the Tuscan Aquifer? That’s the underground reservoir that supplies much of the water for Butte, Glenn, and Tehama counties. The massive “lower” level of this aquifer remains largely untapped because of its depth. A local blogger has a beginner’s course here and here:
“The saturated area of underground substrate (a substrate can be rock, gravel, sand, silt, clay etc.) from which water can be extracted is called an aquifer. The aquifer beneath Chico (and beyond) is called the Tuscan Aquifer. It is named for the ‘Tuscan Formation,’ which are layers of deposits (rock, soil, sand) from ancient streams and volcanic mudflows. (I don’t know who named it the ‘Tuscan,’ though perhaps there is a similar geological formation in the Tuscany area of Italy).
The Tuscan Aquifer is big, though it is hard to be precise regarding its size and shape. Imagine a massive blob of saturated substrate beneath Butte, Tehama, and Glenn Counties, extending to depths of over 1000 feet, containing an estimated 10 times the amount of water as the capacity of Lake Oroville …People move to Chico to go to college, escape the Bay Area, or perhaps to take a job. Other folks might make a list of all the things they are looking for in a town, such as bikeability, sunny weather, a vibrant downtown, attractive city parks, and easy access to mountains and wild areas, and realize that Chico might be the place they want to be. But there are a few folks that move here because of the Tuscan Aquifer …”