How Deep Are Wells in California?
Most California domestic wells run roughly 100 to 600 feet deep, but there is no single standard — the depth depends entirely on where a reliable water-bearing zone sits under your parcel, which varies from under 100 feet in some valleys to 800+ feet in foothill and drought-stressed areas. If you're buying rural California land, the well (or the ability to drill one) is as important as the septic perc test.
Look up a California parcel's well
California drillers must file a Well Completion Report (WCR) with the Department of Water Resources for every well — recording depth, construction, and yield. DWR publishes them in a searchable public database, so before you buy you can often find the depth and water level of the existing well (or nearby wells) rather than guessing.
California-specific: who regulates wells
Wells are permitted by your county (usually environmental health), which enforces the state's well-construction standards (DWR Bulletin 74). Only a C-57 licensed water-well contractor may drill, and the driller files the Well Completion Report with the state. Since 2014, the Sustainable Groundwater Management Act (SGMA) also governs pumping in over-drafted basins — which can affect new wells in some areas.
Frequently Asked Questions
How deep is a typical well in California?
It varies enormously by region and groundwater depth, but most California domestic (household) wells fall roughly between 100 and 600 feet. Shallow alluvial valleys can produce water at under 100 feet; foothill, mountain, and drought-stressed groundwater-basin areas often require 400–800+ feet. There is no single 'standard' California depth — the driller sets it by where a reliable water-bearing zone is found for your specific parcel.
How can I find out how deep a well is on a California property?
California drillers must file a Well Completion Report (WCR) with the Department of Water Resources for every well, recording its depth, construction, and yield. DWR publishes these in a public online database you can search by location. For a specific parcel, ask the seller for the WCR, check the county well-permit file, or search the DWR Well Completion Report map.
How much does it cost to drill a well in California?
Drilling a domestic well in California commonly costs $15,000 to $50,000+, driven mostly by depth — drilling is often priced per foot — plus casing, the pump and pressure tank, electrical, and the county permit. A deep foothill or hard-rock well runs to the high end. Budget for water testing and, on many parcels, a holding tank as well.
How far does a well have to be from a septic system in California?
California setbacks are set locally, but a domestic well must generally be at least 100 feet from a septic leach field/dispersal area (more from certain components or on some soils), plus setbacks from property lines, surface water, and other contamination sources. On a small parcel these distances can conflict — check both the well and septic setbacks with your county environmental health department before assuming a parcel can have both.
Do I need a permit to drill a well in California?
Yes. A well permit is required and is issued by your county (usually the environmental health department), which enforces state well-construction standards (DWR Bulletin 74). Only a C-57 licensed water-well contractor may drill it, and the driller files the Well Completion Report with the state afterward.
Is groundwater getting deeper in California?
In many areas, yes. Drought and long-term overdraft have lowered water tables in several California groundwater basins, and some shallow wells have gone dry, requiring deeper replacements. The Sustainable Groundwater Management Act (SGMA) is now bringing over-pumped basins toward balance, but on rural land it's wise to confirm recent well depths and water levels for the area, not just older reports.
Learn More
California-specific educational overview, not engineering advice. Well depths, costs, and setbacks vary by parcel and county. Well data and standards come from the California DWR Well Completion Report database and Department of Water Resources; permits and setbacks are set by your county. Confirm specifics locally before buying or drilling.