NorCal Civil Engineering Inc

08/27/2026

California’s New Zone 0 Rule: What Property Owners Need to Know

California is taking another step toward reducing wildfire risk around homes and other structures with new Zone 0 defensible-space regulations.

Zone 0 refers to the first five feet immediately surrounding a structure. The goal is to reduce materials that could allow wind-blown embers to ignite a fire next to a building.

The California Board of Forestry and Fire Protection approved the statewide Zone 0 regulations on August 19, 2026. The regulations still must complete the final state administrative process before becoming effective statewide.

What Does Zone 0 Mean?

Zone 0 focuses on creating an ember-resistant area immediately around a structure.

Depending on the property and location, requirements address:
• Combustible vegetation and mulch
• Leaves, pine needles, and other debris
• Firewood and combustible storage
• Vegetation under decks and stairs
• Fences and gates near structures
• Tree branches and other potential fuel
• Materials stored against or underneath buildings

Zone 0 does not necessarily mean removing every plant within five feet of your home. The regulations allow certain maintained vegetation while establishing restrictions on combustible materials and vegetation in specific areas.

How Do I Know If Zone 0 Applies to My Property?

This is one of the most important questions for property owners.

The statewide defensible-space requirements apply to properties within California's State Responsibility Area (SRA) and occupied structures within Very High Fire Hazard Severity Zones (VHFHSZ) in Local Responsibility Areas (LRA).

Check Your Property on California's Official Fire Hazard Map

The California Office of the State Fire Marshal provides an online Fire Hazard Severity Zone map where property owners can enter their address and view the fire hazard designation for their property.

Check the California Fire Hazard Severity Zone Map
https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/fire-hazard-severity-zones

The state map can help you determine whether your property is located within a designated fire hazard area. The current SRA Fire Hazard Severity Zone viewer is based on maps effective April 1, 2024.

A Simple Three-Step Check

1. Look up your address.
Use the California Office of the State Fire Marshal's Fire Hazard Severity Zone map.

2. Determine whether your property is in the SRA or an applicable VHFHSZ.
Properties in the SRA are subject to the statewide defensible-space requirements. For properties in an LRA, the relevant designation is generally a Very High Fire Hazard Severity Zone.

3. Check with your local jurisdiction or fire district.

Local requirements may apply in addition to the state regulations.
Important: A Fire Hazard Severity Zone map is a tool for identifying areas of increased wildfire hazard. It does not necessarily tell you the complete set of requirements that apply to your individual property.

Why It Matters for Rural Properties

Zone 0 is particularly important for rural properties where homes may include:

• Wood fencing and decks
• Detached garages, barns, and agricultural buildings
• Sloped terrain
• Mature trees and native vegetation
• Long driveways
• Septic and water systems
• Retaining walls and drainage improvements

Wildfire preparation should be considered as part of the overall site design, not simply as landscaping.

For example, removing vegetation and replacing it with gravel or other hardscape can change how stormwater flows across a property. On a sloped site, that could create erosion or drainage problems if it isn't properly planned.

Planning for Zone 0

If you live in a wildfire-prone area, now is a good time to evaluate the first five feet around your structures.

Look for:
• Accumulated leaves and debris
• Combustible materials stored near buildings
• Firewood near structures
• Vegetation contacting buildings or decks
• Combustible mulch
• Fences connecting to structures
• Vegetation or debris underneath decks and stairs

If you are planning a new home, ADU, w**ery, agricultural building, remodel, or other rural development, Zone 0 should be considered during the site-planning process.

Coordinating wildfire protection with grading, drainage, septic, access, landscaping, and building design can help avoid costly changes later.

What Should Sonoma and Napa Property Owners Do?

First, determine whether your property is subject to the statewide Zone 0 requirements or additional local regulations.

Then look at the entire property—not just the area immediately around the house.

For rural properties, wildfire mitigation can affect other aspects of site development, including drainage, erosion, access, septic systems, landscaping, and future construction.

Planning ahead can make your property safer and your future project easier to permit and build.

NorCal Civil Engineering works with Northern California property owners, architects, contractors, and other consultants on rural site development, including grading and drainage, septic and wastewater systems, water systems, site planning, surveying, and permitting.

Zone 0 is about more than clearing five feet around a building. It's about creating a safer, more resilient property—and planning the entire site to work together.

Zone 0 regulations are subject to final state administrative approval and implementation. Requirements may vary by location. Always verify current requirements with the California Office of the State Fire Marshal and your local fire protection agency or jurisdiction before beginning work.

08/12/2026

Napa County Groundwater Sustainability Fees Update

Sharing this update from the county. The Napa County Board of Supervisors on August 11 approved first-year groundwater sustainability fees for Fiscal Year 2026–27 that are approximately 55% lower than the maximum rates adopted last year for agricultural users, domestic well owners and public water systems. The fees fund groundwater monitoring, planning, and other activities required under California's Sustainable Groundwater Management Act (SGMA) and will appear on property tax bills mailed later this fall.

“Protecting our groundwater is essential to Napa County’s future,” said Amber Manfree, Chair of the Napa County Board of Supervisors. “These reduced first-year fees allow us to continue implementing the Groundwater Sustainability Plan while recognizing the economic challenges facing many groundwater users.”

The reduced fees reflect updated information provided by groundwater users, including corrections to property information and irrigation practices, as well as the Board's decision in June to use $750,000 from the Groundwater Sustainability Agency's fund balance to offset first-year costs.

Agricultural users pay a base fee for planted acreage, with an additional fee only for acreage irrigated with groundwater. Fees also apply to self-supplied users (including domestic well owners), and public water systems. The fee breakdown is as follows:

Agricultural userbase rate: $17.53 per planted acre
Agricultural user irrigating additional rate: $26.91 per groundwater-irrigated acre
Agricultural user combined rate: $44.44 per planted acre
Self-supplied user (i.e. domestic well owner) rate: $28.17 per parcel
Public water system user rate: $58.47 per acre-foot

The Groundwater Sustainability Fee applies only to groundwater users within the Napa Valley Subbasin. Properties served by municipal water systems in the Cities of Napa, St. Helena and Calistoga and the Town of Yountville are not subject to the fee.

Following public outreach and additional review of property information provided by groundwater users, the Board of Supervisors approved contributing $750,000 from the Groundwater Sustainability Agency's fund balance to reduce first-year fees while maintaining full funding for implementation of the Groundwater Sustainability Plan.

“By significantly reducing the groundwater fees, we’ve struck a responsible balance of protecting the Subbasin’s groundwater, while minimizing the financial impact on our local groundwater users,” said Manfree.

https://www.napacounty.gov/3983/Groundwater-Sustainability-Fee

07/22/2026

Sonoma County OWTS Manual Update

https://permitsonoma.org/owtsmanual #

There are identified significant revisions the county proposed which the North Coast Regional Board approved on June 5, 2026. You can go directly to county website. Below is a long list as well.

Reserve replacement areas. Language has been proposed clarifying the use of a vetted reserve replacement area does not require another replacement area. (Section 4.3)

Easements. Clarifying language regarding abutting lots and easements. The intent is to allow easements on abutting lots and not allow easements to a parcel that is one or more parcels removed from the subject parcel. (Section 4.5)

OWTS replacement under a repair permit. OWTS Manual v7.0 authorizes an OWTS repair permit to include up to 50% of a replacement system. The RWB denied the prior LAMP due to this provision. Staff have revised this provision to allow an OWTS repair permit to include up to 25% of a replacement system. (Section 4.10)

Many variances are “tried and true” and were standardized in the current OWTS Manual Section 17 Table 1. These are proposed to be moved to the relative sections as exceptions. Others are presented in Section 4.16. This approach allows the “variance” to be accepted as part of the OWTS design versus requiring a separate “variance” application. (Section 4.16; Section 17)

Percent Encumbrance and Reserve Areas. Proposed development can affect reserve replacement areas by building over the top of them. The proposal is to require a reserve replacement area(s) when the proposed development creates more than 50% land encumbrance. This can be satisfied by documenting an existing reserve area(s) or creating one. If the proposed development creates 50% or less percent encumbrance, the reserve replacement area(s) is/are required to be shown only if they exist. Development within an encumbered area (stream or well setback for example) does not add to the percent encumbrance. (Section 6.6)

Shifting site evaluation work to designers. Site evaluations take three forms: The concept is to shift this work to solely design professionals, freeing up staff to focus on plan reviews. Revisions were needed to eliminate applications for site evaluations, to require the site evaluation information be submitted in the OWTS Design Report when the OWTS application is submitted, and clarification on how to document the site evaluation information.
(Section 7)
Soil depth and type
Percolation rate
Groundwater elevations

Site Evaluation Area and Site Evaluation Radius. Each site evaluation location has an effective radius. Combining these areas creates a Site Evaluation Area where the OWTS can be located. The effective radii for each type of site evaluation are proposed to be (Section 7-13):
Soil evaluations: 50 feet
Groundwater elevations: 50 feet
Percolation tests: 25 feet

Separation distances for Mound and At-Grade OWTS. OWTS need to be separated to ensure proper functionality and to protect the downslope soil for future use. The separation distances are frequently debated on a project-by-project basis due to not being in the standards. The concept is to create minimum setbacks that ensure proper functionality and reduces delays in the plan review process.
These systems have internal distances from the point of dispersal to edge of the sand toe (Mounds) and to the edge of fill (At-Grades) that allows for abutting of the external edges.

For Mound OWTS the proposed setback allows abutting the toe of primary OWTS sand layer to the toe of the second or reserve OWTS sand layer. (Section 13.3)

For At-Grade OWTS the proposed setback allows the abutting the toe of the primary OWTS fill layer to toe of the second or reserve OWTS fill layer. (Section 13.4)

Drip Systems. The current OWTS Manual provides for sub-surface drip OWTS. The revised manual proposes an “at-grade” drip system provide there is a minimum of 24 inches of good soil below and a minimum of six inches of cover soil. (Section 13.5)

Operational Monitoring Program. The current OWTS Manual requires non-standard OWTS to be in the Operational Monitoring (OPR) Program. In 2023, the County revised this program to only require OWTS with a supplement treatment unit be placed in the OPR program. The proposed OWTS Manual catches up to this change. (Section 14)

State OWTS Policy Tier 3. Section 19 has been added to address impaired water bodies, TMDLs and Advanced Protection Management Plans. (Section 19)

State OWTS Policy Tier 4. Section 20 has been added to address OWTS that need corrective action. (Section 20)

Cesspool Conversion. A subsection of Section 20 allows for the conversion of cesspools. Cesspools are prohibited by the RWB’s and the State OWTS Policy. The County provides for a cesspool conversion that waives the typical site evaluation requirements to encourage removing cesspools from the landscape. As part of Section 20, a cesspool conversion does not authorize new or additional development or re-construction of existing structures. (Section 20).

Waterless Toilets. In 2023, the County revised section Sonoma County Code section 26 to allow for non-flush toilets (waterless toilets). The proposed OWTS Manual catches up to this change. (Section 21)

OWTS not authorized by the State’s OWTS Policy. The proposed OWTS adds a section to provide direction if a OWTS does not meet the minimum standards of the OWTS Policy. (Section 22)

06/11/2026

Napa County Shares Information on Groundwater Sustainability Fee, Upcoming Community Meetings

Sharing this update and information for those who are interested. If you got a postcard, you should have these details for the upcoming meeting options. It will be interesting to see what the fee structure ends up being.

Napa County is encouraging property owners and groundwater users within the Napa Valley Subbasin to review information regarding the Groundwater Sustainability Fee, which will first be assessed in Fiscal Year 2026–27 and supports implementation of the Napa Valley Subbasin Groundwater Sustainability Plan.

The fee was adopted by the Napa County Groundwater Sustainability Agency in December 2025 and is authorized under California's Sustainable Groundwater Management Act (SGMA), a state law that requires local agencies to sustainably manage groundwater resources. The fee funds groundwater monitoring, reporting, planning, administration, and compliance activities required under the law. It is not a charge for water use or a fee that provides access to groundwater. It is a fee for the benefit conferred upon users of the groundwater resources within the Napa Valley Subbasin.

Since 2019, groundwater sustainability efforts in Napa County have been funded through a combination of County General Fund contributions and state grants. While the County will continue contributing $500,000 annually from the General Fund and pursuing grant opportunities, the Groundwater Sustainability Agency has established a local funding source to support the ongoing work required to implement the Groundwater Sustainability Plan.

To help affected property owners understand the fee and determine whether it applies to their property, Napa County mailed informational postcards this week to groundwater users within the Napa Valley Subbasin. Three versions of the postcard were developed for agricultural users, self-supplied users (including most domestic well owners), and public water systems. Each postcard includes information specific to that user group and directs recipients to online Frequently Asked Questions.

"We want to ensure that property owners have clear information about the fee, understand whether it applies to them, and know where to go with questions," said Jamison Crosby, Napa County Natural Resources Conservation Manager. "We encourage anyone who receives a postcard to review the FAQs and attend one of the upcoming community meetings."

The Groundwater Sustainability Fee applies only to properties located within the Napa Valley Subbasin and generally does not apply to properties served by municipal water systems in the Cities of Napa, St. Helena, and Calistoga or the Town of Yountville.

Property owners who believe their well is located outside the Napa Valley Subbasin, or who identify inaccuracies in the information associated with their property, should contact Napa County by July 10, 2026, so records can be reviewed and updated if necessary.

Napa County will host two virtual community meetings to provide additional information and answer questions:

Wednesday, June 17, 2026
3:00 p.m. to 4:30 p.m.
https://countyofnapa.zoom.us/webinar/register/WN_KmnmOjWnQtOfT9CzMUaR_Q #/registration

Wednesday, July 1, 2026
5:30 p.m. to 7:00 p.m.
https://countyofnapa.zoom.us/webinar/register/WN_88XieSrKReG-uPO6E1NQUw #/registration

Visit the Napa County website for Frequently Asked Questions, fee information, and additional groundwater sustainability resources.
https://www.napacounty.gov/3983/Groundwater-Sustainability-Fee

Questions may also be sent via email or 707-253-4471. [email protected]

About the Napa County Groundwater Sustainability Agency
The Napa County Groundwater Sustainability Agency is responsible for implementing the Napa Valley Subbasin Groundwater Sustainability Plan, which was developed in response to California's Sustainable Groundwater Management Act. The plan is intended to protect local groundwater resources and maintain local control of groundwater management for future generations.

06/04/2026

California Water Boards has launched their new dashboard tool.
With this tool, you can easily access detailed information about individual water suppliers across the state, including their progress towards meeting annual objectives for efficient water use.

State of California

05/11/2026

Napa County Affordable Accessory Dwelling Unit program to host information sessions

Homeowners in Napa County, including American Canyon, Calistoga, Napa, St. Helena, Yountville, and the unincorporated Homeowners in Napa County, may be eligible for a forgivable loan of up to $105,000 to build an Affordable Accessory Dwelling unit (AADU).

The Napa County Affordable ADU (AADU) Program is designed to expand affordable housing and increase flexible housing options for homeowners and the local workforce. Homeowners interested in building an affordable ADU and renting it to an income-qualified tenant are invited to attend upcoming information sessions on Wednesday, May 13, 2026 in American Canyon or on Thursday, June 11, 2026 in Calistoga.

The informational sessions will cover:

* Loan Amounts: Forgivable loans ranging from $60,000 to $105,000, depending on unit size and project-specific conditions
* Loan Forgiveness: Loans are fully forgiven over a five-year period when program requirements are met
* Tenant Eligibility: Requirements for income-qualified tenants and how the County supports tenant certification
* Building an ADU: Overview of the development process, including information from the Napa Sonoma ADU Center and County planning and building staff

Whether homeowners are in the early planning stages or ready to build, these sessions provides a clear roadmap to help homeowners benefit from the Napa County Affordable ADU program.

American Canyon Event Details: Learn About Napa County's Affordable ADU Forgivable Loan Program
Date: Wednesday, May 13, 2026
Time: 6:00-7:30 p.m.
Location: American Canyon City Hall, 4381 Broadway Napa
Live Spanish translation provided.
RSVP: Learn about Napa County's Affordable ADU Forgivable Loan Program Tickets, Wednesday, May 13 • 6 PM - 7:30 PM | Eventbrite

Calistoga Event Details: Learn About Napa County's Affordable ADU Forgivable Loan Program
Date: Thursday, June 11, 2026Time: 6:00-7:30 p.m.
Location: Calistoga Community Center, 1307 Washington Street, Calistoga
RSVP: Learn about Napa County's Affordable ADU Forgivable Loan Program Tickets, Thursday, June 11 • 6 PM - 7:30 PM | Eventbrite

04/02/2026

Napa River Flood Protection Project

https://www.napacounty.gov/1083/Napa-RiverCreek-Flood-Protection-Project

This is an interesting project that has moved into a new phase as shown by the map. Have you checked out the new features yet?

03/17/2026

Napa County Groundwater Sustainability

The NCGSA adopted Resolution 2025-05 on December 9, 2025, to implement Groundwater Sustainability fees in the Napa Valley Subbasin, as authorized by Water Code § 10730 to support implementation of the Groundwater Sustainability Plan. The Groundwater Sustainability fees were established based on the Rate and Fee Study (December 2025).

Properties in the Napa Valley Subbasin, excluding those in the City of Calistoga, City of St. Helena, City of Napa, and the Town of Yountville municipal service districts, are subject to the ground water fees.

Find out if your property is subject to this fee .https://www.napacounty.gov/3983/Groundwater-Sustainability-Fee

02/12/2026

Wet Weather Septic System Evaluations in Sonoma and Napa Counties

What Property Owners and Buyers Need to Know
In Sonoma and Napa Counties, wet weather groundwater testing is a critical part of septic system evaluation and permitting. Because both counties have areas with high seasonal groundwater, clay soils, vineyards, and sensitive watersheds, local environmental health departments require careful review of septic system performance during the rainy season.
If you are building, replacing a system, or buying property with septic, understanding wet weather requirements can save time, money, and major headaches.
________________________________________
Why Wet Weather Testing Matters in W**e Country

Septic drainfields rely on unsaturated soil to treat wastewater. During Northern California’s rainy season (typically November–April):
• Groundwater levels rise
• Clay soils become saturated
• Drainfields may lose vertical separation
• Effluent treatment effectiveness can decrease
• Systems may back up or surface
Both counties require confirmation that adequate separation exists between the bottom of the drainfield and the seasonal high groundwater table.
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Sonoma County Septic Requirements

Sonoma County Permit Sonoma Environmental Health Division oversees onsite wastewater treatment systems (OWTS).
Wet Weather Groundwater Determination
Sonoma County:
• Establishes an official “wet weather testing period”
• Opens testing only after sufficient cumulative rainfall
• Requires groundwater observations during this period for many
new or replacement systems
Testing may involve:
• Excavated test pits
• Observation holes
• Temporary monitoring wells
• Soil profile evaluation for redoximorphic features (indicators of
seasonal saturation)
Vertical Separation
Typical minimum vertical separation:
• 2–4 feet between trench bottom and seasonal high groundwater
(Exact requirement depends on system type and soil conditions.)
If insufficient separation exists, alternatives may include:
• Raised mound systems
• Engineered systems
• Pressure distribution
• Sand filtration components
________________________________________
Napa County Septic Requirements

Napa County Environmental Health also requires wet season groundwater evaluation for many new and replacement systems.
Key elements include:
1. Soil Profile Evaluation
• Identification of seasonal high groundwater indicators
• Soil texture and structure analysis
• Depth to limiting layers
2. Wet Season Testing Window
• Evaluations must occur during the rainy season
• Rainfall thresholds must be met
• Field observations are documented by a Qualified Professional
3. Replacement Area Requirement
Napa County requires a designated replacement drainfield area that must also meet groundwater separation standards.
________________________________________
When Wet Weather Testing Is Required

You may need wet weather testing if you are:
• Building a new home
• Replacing a failed septic system
• Expanding a home (bedroom additions increase septic design
flow)
• Subdividing property
• Developing vineyard housing or rural structures

For real estate transactions, wet weather testing is not always automatically required, but it is strongly recommended if:
• The system is older
• The property is near a creek or floodplain
• The area is known for high groundwater
• There are signs of seasonal saturation
________________________________________
What the Evaluation Process Looks Like

1. Hire a Qualified Professional (QP)
Typically a civil engineer, registered environmental health
specialist, or licensed septic designer.
2. Soil and Site Evaluation
o Test pits dug to 7–10 feet (or refusal)
o Soil logged and described
o Groundwater indicators documented
3. Wet Weather Observation
o Groundwater measured during rainy season
o Rainfall totals verified
4. Percolation Testing (if required)
5. Report Submission to County
6. County Review and Approval
________________________________________
Common Challenges in Sonoma & Napa

High Clay Content Soils
Slow percolation and drainage limitations.
Shallow Bedrock
Limits trench depth and vertical separation.
Seasonal Perched Water Tables
Common in valley areas.
Creek and Watershed Protection
Additional setbacks may apply near water bodies.
________________________________________
Costs to Expect

Wet weather testing and site evaluation typically cost:
• $2,500–$6,000+ for evaluation and reporting
• More if monitoring wells are required
• Engineered systems can range $20,000–$50,000+ if site
constraints exist
Costs vary widely based on terrain, soil, and complexity.
________________________________________
Tips for Property Buyers

If purchasing in Sonoma or Napa:
• Request septic records from the county
• Confirm permit history
• Ask when the system was last pumped
• Consider a wet weather evaluation if buying in winter
• Verify there is a code-compliant replacement area
A failing septic system in these counties can significantly impact property value and escrow negotiations.
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Bottom Line

If you’re planning development or purchasing rural property, consult a local Qualified Professional early in the process. Wet weather testing windows are seasonal — missing the rainy period can delay your project until the following winter.

12/18/2025

As reported in the Press Democrat, the Napa County Board of Supervisors on Tuesday approved the county’s first effort to define how a new state law that opens up tasting experiences directly in vineyards will work in the Napa Valley.

The pilot program implementing that law, Assembly Bill 720, is set to run from Jan. 1, 2026, to July 1, 2027, while county staff work to figure out permanent rules. The new law allows w**eries to host small “estate tasting events” at vineyard sites with only a permit from the state Department of Alcoholic Beverage Control when it becomes effective.

California Assembly Bill 720 (AB 720) for the 2025-2026 session significantly impacts w**eries by creating a new permit for off-site vineyard tastings, offering them more flexibility, and delaying
California Redemption Value (CRV) labeling deadlines for w**e containers, allowing more QR code use. It allows for "pop-up" tastings at controlled vineyard sites, pushes the main CRV label date to 2026, and offers regulatory relief for existing bottled w**e.

Key Provisions of AB 720 (2025-2026 Session)
• Estate Tasting Event Permit: Allows w**eries to host tastings at non-adjacent vineyards they control, offering new consumer experiences.
• CRV Labeling Relief: Extends the deadline for new w**e containers to have CRV indicia from July 1, 2025, to July 1, 2026.
• Exemptions: Delays the permanent exemption for already-bottled w**e from CRV labeling to July 1, 2025.
• QR Code Flexibility: Permits the use of smaller, half-inch QR codes for compliance.
• Fees & Limits: Imposes a $200 annual fee for the new permit and limits it to 36 events per licensee yearly, with transferability.

Why It Matters
• For W**eries: Provides greater freedom to host unique tasting experiences and more time to comply with complex recycling regulations.
• For Consumers: More opportunities for authentic w**e experiences at vineyard sites.
• Economic Impact: Supports California's w**e industry by easing regulatory burdens and fostering tourism.

Bill Status
• Introduced in February 2025 and passed, becoming Chapter 562, Statutes of 2025, in October 2025, making it law.