California county profile

Santa Clara County

Santa Clara County has one of the most expansive habitat conservation programs in the Bay Area, covering a large fraction of the county's unincorporated land, while nearly half of all county land area is simultaneously under Williamson Act agricultural contracts that restrict what rural parcels can do.

1.9M residents
9 local environmental rules on the books
1.7K projects filed for environmental review 67% routine · 14% mitigated · 7% full review

What catches people off guard in Santa Clara County

Habitat plan countywide fees

The Santa Clara Valley Habitat Plan applies to a large portion of unincorporated county land, covering a broad list of sensitive species — and mitigation fees are assessed per project without requiring a separate project-level biological study for each development.

Williamson Act: large land area

Nearly half of the county's total land area is under Williamson Act agricultural contracts, making rural parcel owners in the foothills and south county subject to land use restrictions that run with the land for long contract terms — a frequent surprise in agricultural escrow transactions.

Hillside slope density rules

The county's hillside combining district reduces allowable density as slope increases, and development on steep terrain must demonstrate it can't be placed on a less steep portion of the lot — a requirement that catches hillside projects early in entitlement.

Serpentine soil sensitivity

The east foothills contain significant areas of serpentine soils that support rare plant communities not found in typical valley terrain — projects in those areas may encounter botanical survey requirements that are rarely triggered elsewhere in the county.

Coyote Valley wildlife corridor

The undeveloped Coyote Valley between San Jose and Morgan Hill is a recognized wildlife movement corridor — projects in that zone face biological review focused on preserving connectivity between the foothills, not just protecting on-site resources.

Cities in Santa Clara County

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Source: Headlands Environmental — environmental site screening for California. Rules summarized from publicly available county codes and planning documents; project review counts indexed from the State Clearinghouse. For authoritative requirements, consult Santa Clara County directly.