Geologic Hazard Assessment (GHA)

Geologic Hazards Assessments are site specific evaluations of potential geologic hazards. These assessments are typically completed by the County Geologist, but may also be completed by a private Professional Geologist and submitted for review. Geologic Hazard Assessments are typically required for development or development activities in areas of potential geologic hazards. However, this requirement may be waived by the County Geologist if adequate information is available through technical or field review to determine geologic requirements, including if a full geologic report is required.

A geologic hazard assessment is a summary of the potential geologic hazards present at a site that may affect your project. GHA’s are generally conducted by the County geologic staff; however GHA’s can be done by an outside consulting geologist and submitted for review.

A Geologic Hazard Assessment may be required for development or development activities in areas including, but not necessarily limited to: County and State Fault Zones, sites with suspected slope instability concerns, FEMA designated floodplains and floodways, coastal hazard areas, and other areas of potential geologic hazards as determined by the County Geologist.

A geologic hazard is defined as a threat to life, property, or public safety caused by geologic or hydrologic processes. Santa Cruz County is subject to significant geologic hazards including, but not necessarily limited to, the following:

  • Surface Fault Rupture
  • Ground Cracking
  • Liquefaction and Lateral Spreading
  • Tsunami
  • Severe Ground Shaking
  • Shallow and Deep-Seated Landsliding
  • Coastal Bluffs and Beaches
  • Landslide-Initiated or Post-Wildfire Debris Flows

  1. Contact County geologic staff to discuss the proposed scope of work first: geologichazards@santacruzcountyca.gov.
  2. Applications for GHA’s are prepared online and the following are minimum submittal requirements:
    • a site/topographic plan indicating the proposed development including septic locations and all access ways to buildings
    • building plans and pertinent geologic/geotechnical reports (if developed)
    • payment of the application fee
  3. Please stake the corners of the building site and septic location in the field.

County geologic staff will conduct a site visit, consult hazards maps, and write an evaluation of the site conditions and permit requirements. Possible requirements from the evaluation include:

  • Preparation of an engineering geologic report prepared by a State registered geologist
  • A soils report prepared by a geotechnical engineer or a registered civil engineer who specializes in geotechnical engineering

Any required geologic, soil, or other technical report shall be completed, reviewed and accepted pursuant to the provisions of this section before any public hearing is scheduled and before any discretionary or development application is approved or issued. The County Geologist may agree to defer the date for completion, review, or acceptance of any technical report where the technical information is 1) unlikely to significantly affect the size or location of the project, and 2) the project is not in the area of the Coastal Zone where decisions are appealable to the Coastal Commission. In no event shall such be deferred until after the approval or issuance of a building permit

When the geologic hazards assessment and any additional reports have been completed, the County Geologic staff will state what conditions of approval will be placed on the building or development permit, such as:

  • Project modification or relocation
  • Grading and drainage requirements
  • Meeting all report recommendations
  • Elevation of the structure
  • Using a specified envelope for the septic system leach field
  • Filing a Notice of Geologic Hazards with the County Recorder

Decisions which enforce provisions of the Geologic Hazards Ordinance may be appealed to the Director. See the Appeals webpage.

If you have any questions regarding the Geologic Hazards Assessment process or whether a GHA might be required for your project, please contact County Geologic staff geologichazards@santacruzcountyca.gov