Every home in Clayton's Oakhurst neighborhood carries two separate charges that have nothing to do with each other. One is an HOA due, paid to whichever sub-community a lot sits in, covering landscaping, pool access, or exterior maintenance. The other is a countywide special assessment for slope stability, and it shows up on the property tax bill itself rather than in any homeowner association statement. Most buyers never see the two pulled apart until they're deep in escrow reading a preliminary title report.

In June 2025, that second charge changed for the first time in twenty five years. It also stopped being a flat number and became one that depends on how close a specific parcel sits to the hillside behind it.

Two Bills, Same Neighborhood

Oakhurst is not one HOA. It's a collection of them, built out starting in 1990 around the golf course at Oakhurst Country Club, with condo and duet complexes like Chaparral Springs and Black Diamond layered in around it. Dues vary by complex. Black Diamond's duets have run around $340 a month. Some condo complexes in the area run closer to $450 a month once clubhouse, pool, water, and garbage are bundled in. None of those numbers include the item that actually funds hillside stability.

That item is the Oakhurst Geologic Hazard Abatement District, or GHAD, a public agency created under a Plan of Control adopted in 1990. The Clayton City Council sits as its board. Its job isn't landscaping or a clubhouse roof. It's monitoring the ground itself, through V-ditches that route runoff away from slopes, inclinometers bored deep into hillsides to track earth movement, and piezometers that measure water pressure underground. An engineering firm, BSK Associates, inspects the district annually and reports back to the council on what's holding and what isn't.

A District That Went Twenty-Five Years Without a Raise

The GHAD's rate structure hadn't been raised since 2000, an assessment level set before California's Proposition 218 made increases subject to voter approval. A council review in 2023 found the district collecting about $47,000 a year, an amount that had crept up slightly through cost-of-living adjustments but had never been reset. That same review turned up a harder problem than an outdated number. Several of the inclinometers used to detect ground movement had been damaged or gone inoperable, meaning the district had no current data on whether parts of Oakhurst were shifting at all. By the time the district put a rate increase to a vote in 2025, annual revenue had drifted up to roughly $51,000, still far short of what the engineers said the job required.

City estimates put the actual funding need at roughly $360,000 a year on top of the existing $51,000, covering deferred maintenance, working monitoring equipment, and a reserve large enough to respond if a slope actually failed. That gap sat unaddressed for years before it reached a ballot.

How the Vote Actually Worked

Because a GHAD assessment increase falls under Proposition 218, it required a mailed ballot to every affected owner rather than a simple council vote. The district sent ballots to 1,484 Oakhurst property owners in the spring of 2025 and received 565 back, a 38.1 percent return. Votes were weighted, meaning parcels facing higher geologic risk or carrying higher assessed value counted for more than a flat one-owner-one-vote count would suggest.

The weighted tally came out to 51.1 percent in favor against 48.9 percent opposed. Converted to the dollar terms the weighting actually runs on, it passed $66,161.99 to $63,391.24. It's the first assessment increase the district has passed since it was established.

Not everyone in Oakhurst agreed it should have. Some owners questioned whether the city might redirect the funds elsewhere, a claim longtime councilmember and six-time mayor Julie Pierce disputed directly, saying the money collected cannot be used for anything else in the city. Pierce, who was on the council when the GHAD was formed, argued the increase was overdue. "If a natural disaster like a landslide were to happen in Oakhurst, there would not be enough money in the fund to repair it," she said.

There was also disagreement over whether Proposition 218's usual two-thirds threshold for special taxes should have applied at all, since GHAD assessments are legally treated as benefit assessments rather than taxes. Under the simple-majority standard the district used, the increase passed. Under a two-thirds standard, it would not have.

Why Two Houses on the Same Street Can Pay Different Amounts

The new fee structure runs from $84.39 to $280.41 a year, and where a given parcel lands on that range depends on its risk tier, which is the same logic that determined how much weight its owner's ballot carried in the vote. A house set back from the open space areas pays toward the low end. A house whose yard backs directly onto the slopes bordering Windmill Canyon Drive, where BSK's engineers have documented surface creep and shallow slope sloughing above the V-ditches, pays more.

That means two homes on the same court, same square footage, same HOA, can carry different annual GHAD costs simply based on lot position relative to the hillside. It's not a distinction that shows up in a listing photo or a Redfin filter. It shows up on the assessor's parcel roll and in the district's engineering maps.

What This Means If You're Underwriting a Purchase Here

If you're evaluating a specific address in Oakhurst, the GHAD line item is worth pulling separately rather than assuming it's folded into the HOA quote you already have. It appears on the county tax bill and on the preliminary title report as a special assessment, and the exact dollar amount depends on which risk tier that parcel was assigned during the 2025 process. Because the assessment carries a Consumer Price Index adjustment, the number can also creep upward year over year without another ballot. The city held a public hearing on the annual levy of assessments again in July 2026, confirming this isn't a one-time fee tied to the 2025 vote but a recurring charge the council revisits annually.

Against a citywide Clayton median sale price of $1.08 million as of September 2026, the difference between the low and high end of the GHAD range, under $200 a year, is small relative to the purchase itself. What it buys you is a clearer picture of how a specific lot has actually been underwritten by the engineers who monitor it, which is a different question than whether the HOA pool is heated.

For a buyer weighing two comparable Oakhurst listings, that distinction is the kind of detail worth raising with your agent before you're three weeks into escrow reading a title report for the first time.

If you're comparing homes in Clayton's Oakhurst neighborhood and want someone to walk through what a specific parcel's assessment history and risk tier actually mean for your offer, reach out to Chatterton Homes Group. Ask Cameron for a straight answer before you write the number into your budget.