Photo above: San Ramon City Hall at 7000 Bollinger Canyon Road, where the City Council meets as the Dougherty Valley GHAD board, May 2024. Mx. Granger, CC0, via Wikimedia Commons.
At least one of them, yes. Every home inside the Dougherty Valley Geologic Hazard Abatement District pays a yearly GHAD assessment, proposed at $181.69 per home for 2026/27, and homes in Windemere Ranch also sit in a Mello-Roos district. Whether a specific house adds more special taxes or HOA dues on top shows up on its own Contra Costa County tax bill and HOA papers.
So don’t guess from the neighborhood name. Pull the bill for that parcel. Here’s what each charge is and how to read it.
What is the difference between Mello-Roos, a GHAD and HOA dues?
Three different bills, paid for three different reasons.
- Mello-Roos (a Community Facilities District special tax). A public agency forms a CFD under the state’s Mello-Roos Community Facilities Act of 1982 to pay for infrastructure or services, then levies a special tax on the parcels inside it. The City of San Ramon describes its own CFD this way on its Finance page (checked September 25, 2026).
- GHAD assessment. A Geologic Hazard Abatement District is a public district that watches, prevents and repairs hillside problems like landslides and erosion on the open space it owns. In San Ramon, the City Council sits as the board of the Dougherty Valley GHAD, and City staff run it (City of San Ramon, DV GHAD page, checked September 25, 2026).
- HOA dues. Paid to a homeowners association for the things it owns and maintains. HOA dues are billed by the association, so they don’t show up on the county tax bill.
Mello-Roos and GHAD charges both ride on the county property tax bill, as separate lines under special taxes and assessments.
What does the Dougherty Valley GHAD charge?
The proposed 2026/27 rate is $181.69 per residential unit per year, the same as the year before. The legal limit is $250 per unit a year (Dougherty Valley GHAD, Notice of Public Hearing for FY 2026/27, dated May 11, 2026). The hearing was set for May 26, 2026, with staff recommending the rate stay at $181.69 (May 26, 2026 agenda). The City’s adopted 2026-27 budget lists setting the 2026-27 GHAD assessments among its completed work, but the minutes of that GHAD meeting were not posted as of September 25, 2026, so confirm the amount on the parcel’s 2026/27 tax bill.
A few facts from that notice and the City’s GHAD page, both read September 25, 2026:
- Where it applies. The district covers the West Branch area at Crow Canyon Road and Dougherty Road, Old Ranch Summit, and Dougherty Valley, about 2,767 acres of open space in total. The City formed it in July 1990 and annexed Dougherty Valley in fiscal year 1997/98.
- What it pays for. Monitoring, yearly inspections by a geologist or geotechnical engineer, weed abatement, cleaning drainage ditches, erosion control and slope repair. Much of the open space is leased for cattle grazing to keep fire fuel down.
- How the money stacks up. The proposed 2026/27 budget in the hearing notice projects $2,218,011 in assessments and a reserve fund balance of $20,238,058 at year end. The reserve is there for large repairs such as landslides.
San Ramon has a second one, the Northwest San Ramon GHAD, formed in 2017 for The Preserve (Faria) project outside Dougherty Valley (City of San Ramon, adopted budget, fiscal year 2026-27). If a home sits in its area, the rate will be on that parcel’s bill.
The GHAD’s District Engineer, Shane Hsieh, takes assessment questions at (925) 973-2681.
Which Dougherty Valley homes have Mello-Roos?
Windemere Ranch does, and that’s the one we could confirm from an official source. The special tax district there is called ABAG Finance Authority for Nonprofit Corporations Community Facilities District No. 2004-2 (Windemere Ranch). Windemere parcels also pay a separate reassessment in the Association of Bay Area Governments Windemere Ranch Reassessment District. Both pay off bonds that built backbone infrastructure, first issued starting in 1999 and later refinanced (Advancing California Finance Authority, Governing Board item 6.a, July 17, 2025).
That same board item describes Windemere Ranch as 2,320 acres, 5,170 homes and fully built out. On July 17, 2025 the board unanimously adopted Resolution No. 2025-006, which directs surplus bond money toward paying down part of the bonds, with the stated purpose of reducing the special taxes and reassessments owners pay (ACFA Governing Board minutes, July 17, 2025). How much any one bill drops, if at all, will show on that parcel’s tax bill.
Gale Ranch, the other half of Dougherty Valley, is a different story on paper. We didn’t find an official document naming a Gale Ranch CFD or its rate, so we won’t name one. If a Gale Ranch parcel carries a special tax, it will be printed on the tax bill with the agency’s phone number next to it.
Are there special taxes outside Dougherty Valley too?
Yes. The City of San Ramon formed Community Facilities District No. 2014-1 in 2014 under the Mello-Roos Act. It started with the Acre subdivision and has grown to include The Preserve (formerly Faria Preserve), Promenade, 500 Deerwood, Aspenwood and 2481 Deerwood, split across three tax zones (City of San Ramon, Finance page on GANN Limits, checked September 25, 2026). None of those are in Dougherty Valley, but they show that some newer San Ramon subdivisions carry a CFD line too.
What else is on every San Ramon tax bill?
The school district parcel tax. San Ramon Valley Unified’s Measure Q charges $144 per parcel a year, starting July 1, 2025 and ending June 30, 2034. Owners 65 and older who live in the home, and owners receiving SSI or SSDI disability benefits who live in the home and fall under the district’s income limit, can apply for an exemption; forms are due May 31 for the next tax year (SRVUSD, Parcel Tax Information page, checked September 25, 2026).
So a Dougherty Valley bill usually shows at least two extra lines, the GHAD and the SRVUSD parcel tax, plus whatever CFD or reassessment the parcel carries.
How do I check one Dougherty Valley address?
Five steps. Do them before your contingencies run out.
- Pull the tax bill. Search the address or parcel number in the Contra Costa County Tax Portal at taxcolp.cccttc.us/lookup, or call the Treasurer-Tax Collector at (925) 608-9500 (Contra Costa County, Secured Property Taxes page, checked September 25, 2026).
- Read the left-hand box. The county’s own guide to its bill says special taxes and assessments are listed separately, are not based on the Assessor’s value, and should be questioned by calling the agency at the phone number printed next to each charge (Contra Costa County, How to Read the Annual Secured Property Tax Bill).
- Call the agency on each line. Ask what the charge pays for, whether it can rise, and when it ends.
- Ask for the seller’s Mello-Roos notice. Under Civil Code 1102.6b, a seller whose parcel carries a Mello-Roos special tax lien must make a good faith effort to get a disclosure notice from each agency that levies it and give it to the buyer.
- Get the HOA package if there’s an association. Civil Code 4525 lists what the seller must provide, including the governing documents and a written statement of current regular and special assessments and anything unpaid (California Legislative Information, checked September 25, 2026). Read the budget and reserve study too.
One catch. Your base property tax resets to your purchase price, so the seller’s total won’t be your total. The special tax and assessment lines stay with the parcel, so they carry over. Confirm each one anyway.
Should these charges change which San Ramon home I buy?
Only if they change what you can comfortably pay each month. Add the GHAD, any CFD or reassessment, the parcel tax and HOA dues to your mortgage, insurance and base tax, then compare homes on that full number. A Windemere house and an older home west of I-680 at a similar price can have very different yearly bills.
We explain what’s on the bill. We don’t give tax advice. Ask a tax professional how any of these charges affects your own taxes, ask your lender how they count in your loan approval, and ask the agency named on the bill for the current amount.
Questions people also ask
What is the GHAD fee in Dougherty Valley?
The Dougherty Valley Geologic Hazard Abatement District proposed $181.69 per residential unit for fiscal year 2026/27, unchanged from the prior year, with a legal cap of $250 per unit, per the district’s hearing notice dated May 11, 2026. The hearing was set for May 26, 2026; its minutes were not yet posted as of September 25, 2026. It pays for landslide and erosion work, inspections and fire fuel control on about 2,767 acres of open space. Check the parcel’s tax bill for the amount charged.
Does Windemere in San Ramon have Mello-Roos?
Yes. Windemere Ranch parcels are in ABAG Finance Authority for Nonprofit Corporations Community Facilities District No. 2004-2 (Windemere Ranch) and also pay a reassessment in the ABAG Windemere Ranch Reassessment District, per a July 17, 2025 Advancing California Finance Authority board item. The amount for one home is on its Contra Costa County tax bill.
How do I look up a San Ramon property tax bill?
Use the Contra Costa County Tax Portal at taxcolp.cccttc.us/lookup and search by address or parcel number, or call the Treasurer-Tax Collector at (925) 608-9500. Each special tax and assessment appears on its own line with the agency’s phone number, per the county’s guide to reading the bill. Call that number with questions about a charge.
Is Mello-Roos tax deductible?
That’s a question for a tax professional, not a real estate agent. How a special tax or assessment is treated depends on what it pays for and on current tax rules. Take the parcel’s Contra Costa County tax bill to your tax professional and go through it line by line. The agency named on each line can explain what that charge funds.
Your next step
Found a Dougherty Valley home you like? Send us the address. We’ll pull the county tax bill, list every special tax and assessment line with its agency, and request the HOA package, so you see the real yearly cost before you write an offer. Ask a San Ramon agent on our team or call (510) 949-5525.
More on San Ramon: Is San Ramon a good place to live? · How much does a house cost in San Ramon? · Search San Ramon homes · What’s my home worth?
By Bill Davis, DRE #01880656, The Davis Team at eXp Realty, San Ramon, CA. Updated September 25, 2026.
Sources
- City of San Ramon, Dougherty Valley Geologic Hazard Abatement District page: sanramon.ca.gov/DVGHAD (checked September 25, 2026)
- City of San Ramon, Geologic Hazard Abatement Districts page (lists the Dougherty Valley and Northwest San Ramon GHADs): sanramon.ca.gov (checked September 25, 2026)
- Dougherty Valley GHAD, Notice of Public Hearing to Adopt Annual Assessment for FY 2026/27, with Exhibit A budget, dated May 11, 2026: sanramon.ca.gov City Clerk public hearing notices (read September 25, 2026)
- Advancing California Finance Authority, Governing Board, July 17, 2025, Agenda Item 6.a, Windemere Ranch Infrastructure Financing Program, and meeting minutes (final): abag.ca.gov (read September 25, 2026)
- Dougherty Valley GHAD, May 26, 2026 meeting agenda and agenda packet (staff report and FY 2026/27 Engineer’s Report): sanramonca.portal.civicclerk.com (read September 25, 2026)
- City of San Ramon, Adopted Budget, Fiscal Year 2026-27 (GHAD section and Resolution No. 2026-066, adopted May 26, 2026): sanramon.ca.gov (read September 25, 2026)
- City of San Ramon, Finance, GANN Limits page (Community Facilities District No. 2014-1): sanramon.ca.gov (checked September 25, 2026)
- San Ramon Valley Unified School District, Parcel Tax Information (Measure Q): srvusd.net (checked September 25, 2026)
- Contra Costa County Treasurer-Tax Collector, Secured Property Taxes page and How to Read the Annual Secured Property Tax Bill: contracosta.ca.gov, and Tax Portal at taxcolp.cccttc.us/lookup (checked September 25, 2026)
- California Civil Code 1102.6b and 4525: leginfo.legislature.ca.gov (checked September 25, 2026)