In most of Santa Clara County, home owners do not own the right to drill a well and pump groundwater under their property. That will be clarified in the preliminary title report (similarly, oil and mineral rights are usually not sold with residential neighborhood parcels here). The depth of the water may be of interest, though, as a high water table may have possible risks.
High Water Table Risks
In come cases there could be problems with springs under the home. When that happens, the groundwater may percolate up under the house during times of heavy rains, causing water in the crawl space and possibly creating foundation damage later.
Another risk is underground water moving environmental hazards to your property. A plume of water could potentially move toxins released at a leaking underground storage tank (“LUST” site) to your property’s area, where you may be responsible for the cleanup! (For info on the leaking underground storage tanks, you’d want to read the JCP or similar report for natural and environmental hazards. That will tell you if there are any LUST sites within 1 mile of the property.)
Does your home, or the one you want to buy in the Santa Clara Valley, have a high water table? One way to learn is to check out the interactive map on the Valley Water website. Much or most of Campbell seems to have first groundwater at a depth of 50 to 100 feet. Much of the low-lying areas of San Jose and Santa Clara have water at a mere 0 – 10′!
The interactive map that I saw includes most, but not all, of the valley. Enjoy checking it out!