Buying Land in California: State Rules on Top of County Zoning

If the parcel is in the coastal zone, county zoning is not the whole story

The California Coastal Act of 1976 (Public Resources Code Division 20) created the California Coastal Commission and a statutorily defined coastal zone that runs the length of the state, from the Oregon border to the Mexican border. Under Public Resources Code Section 30103, the coastal zone generally extends inland about 1,000 yards from the mean high tide line in developed areas, but can extend up to five miles inland -- or to the first major ridgeline -- in significant habitat, estuarine, and recreational areas. A rural parcel well outside a town can still fall inside the coastal zone.

Most development inside the coastal zone requires a Coastal Development Permit (CDP), issued by the county itself if it has a Local Coastal Program (LCP) certified by the Coastal Commission, or by the Commission directly where no LCP is certified. A CDP review is discretionary and can include public hearings -- it is a separate approval layered on top of, not a replacement for, the county's ordinary zoning and building permit process.

• Confirm with the county planning department whether the parcel is inside the mapped coastal zone before assuming standard zoning review is all that applies.
• A single-family home is not automatically CDP-exempt in the coastal zone -- exemptions generally cover minor improvements to an existing residence, and narrow sharply near a beach, wetland, or coastal bluff.
• Whether the county or the Coastal Commission is the permitting body depends on LCP certification for that stretch of coast -- ask directly, since it changes how appeals work.

CEQA: environmental review comes with most discretionary permits

The California Environmental Quality Act (CEQA) is separate from the Coastal Act and applies statewide, not just at the coast. Whenever a project needs a discretionary approval from a public agency -- a rezone, a conditional use permit, a subdivision map, or a CDP -- CEQA generally requires that agency (usually the county, acting as 'lead agency' for a private land project) to evaluate the project's environmental effects before approving it. Depending on what that review turns up, the result can be a categorical exemption, a Negative Declaration, a Mitigated Negative Declaration, or a full Environmental Impact Report (EIR).

A single new single-family home is often eligible for a CEQA categorical exemption (commonly the Class 3 'new construction of small structures' exemption), which is why most ordinary rural home-building doesn't turn into a multi-year environmental review. But that exemption can be lost if the site sits in a particularly sensitive environment -- steep slopes, mapped fault or landslide zones, sensitive habitat -- and a project needing anything beyond the routine is far more likely to trigger a fuller review. Whether a specific parcel qualifies is a county-level, project-specific determination, not something to assume from the zoning designation alone.

Groundwater: SGMA changed the rules in 2014, and it is still rolling out

For most of California's history, groundwater pumping was governed by court-made doctrine with no statewide permitting system. That changed with the Sustainable Groundwater Management Act (SGMA), signed in 2014, which required the Department of Water Resources to prioritize every groundwater basin as high, medium, low, or very low, and required local Groundwater Sustainability Agencies (GSAs) to form and adopt Groundwater Sustainability Plans (GSPs) for every basin prioritized high or medium. DWR's prioritization identified 94 basins and sub-basins as high- or medium-priority -- together the large majority of the state's groundwater pumping, population, and irrigated acreage -- and those GSAs are working through 20-year timelines toward sustainability.

For a land buyer, this is a genuinely recent shift, especially in the Central Valley and other heavily pumped agricultural basins: a parcel's well may sit inside a GSA territory with its own pumping allocations, metering requirements, or (in critically overdrafted basins) restrictions on new pumping while a GSP is implemented -- on top of, not instead of, whatever well-permitting the county already requires. Which GSA covers a specific parcel, and what its plan currently requires, has to be checked directly -- it varies basin by basin and is still actively evolving.

Septic systems: a 2013 statewide policy, implemented by county health departments

California regulates septic systems (technically "onsite wastewater treatment systems," OWTS) under the statewide Water Quality Control Policy for Siting, Design, Operation, and Maintenance of Onsite Wastewater Treatment Systems, adopted by the State Water Resources Control Board in 2012 and effective in 2013. The OWTS Policy applies to the roughly 1.2 million septic systems statewide and uses a risk-based, tiered approach to siting and design standards.

The policy keeps county (or, in some jurisdictions, city or special-district) environmental health departments as the local permitting authority, since the State Water Board found local agencies already have the most direct expertise -- while giving the nine Regional Water Quality Control Boards principal responsibility for overseeing implementation. In practice, a county's own Local Agency Management Program, where approved, still handles day-to-day site evaluations and permits, but within tiered standards set at the state level. See our national guides to perc tests and septic systems for the general process; ask the county environmental health department what tier applies to the target site.

What's still decided at the county level

The Coastal Act, CEQA, and SGMA are all real statewide layers, but the actual outcome for a specific parcel is still assembled locally: the underlying zoning designation and allowed uses, whether the county holds a certified Local Coastal Program and issues CDPs itself, which CEQA exemption (if any) applies to a specific project, which GSA and GSP terms cover a specific well, and which tier of the OWTS Policy a specific septic site falls into all come from county records and county staff, not from this page.

That means the state-level picture here tells you what kind of review layers exist and what to ask about -- it does not tell you whether a specific California parcel is buildable, has a viable well, or can perc. That still comes from the county planning department, county environmental health department, and (near the coast) the Coastal Commission or the county's certified LCP, every time.