To: Board of Directors of the Sonoma County Agricultural Preservation and Open Space District
Department or Agency Name(s): Sonoma County Agricultural Preservation and Open Space District
Staff Name and Phone Number: Misti Arias, General Manager, 565-7264; Steph Tavares, Senior Acquisition Specialist, 565-7362
Vote Requirement: Majority
Supervisorial District(s): Second
Title:
Title
Diamond W Ranch Conservation Easement Acquisition (Project No. 0595)
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Recommended Action:
Recommended action
Adopt a Resolution of the Board of Directors of the Sonoma County Agricultural Preservation and Open Space District to:
A) Determine that the acquisition of a conservation easement over the Diamond W Ranch is consistent with the Agricultural Preservation and Open Space District’s Expenditure Plan and the 2020 Sonoma County General Plan;
B) Make certain determinations pursuant to the California Environmental Quality Act and direct the filing of a notice of exemption for the acquisition;
C) Authorize a purchase price of $3,395,000 for the acquisition of the Diamond W Ranch conservation easement;
D) Authorize the President of the Board to execute a conservation easement protecting the property in the form on file with the Clerk, along with the associated certificate of acceptance after all closing conditions are met;
E) Dedicate the conservation easement interests to park and open space purposes pursuant to Public Resources Code section 5540; and
F) Authorize recordation of all instruments necessary to accomplish the transaction, and direct the General Manager, in consultation with County Counsel, to take all other actions necessary or appropriate to establish a permanent conservation easement over the property.
(Second District)
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Executive Summary:
The Diamond W Ranch project is the proposed purchase of a conservation easement over the nearly 850-acre ranch in the Two Rock Valley. This property is a large productive organic dairy and ranch spanning Valley Ford Road with four certificates of compliance and one additional legal lot.
The conservation easement will protect the agricultural, natural resource, and scenic values of the property. Diamond W Ranch is located in the “coastal ag belt” of Sonoma County in an area with more than a dozen other protected agricultural properties. Sonoma County Agricultural Preservation and Open Space District (Ag + Open Space) seeks authorization to pay the appraised value of $3,395,000 for the acquisition of the conservation easement.
Discussion:
Property Characteristics/Project Significance
The Diamond W Ranch project is the proposed acquisition of a conservation easement over an approximately 849.30-acre ranch and dairy near Bloomfield (the Property). Ag + Open Space is proposing to purchase a conservation easement protecting the Property’s agricultural, natural resource, and scenic values. A large area of the Property is visible from Valley Ford Road, a county-designated scenic corridor, with another large area visible from Roblar Road. The Property is directly adjacent to Roblar Ranch and, once protected, the Diamond W Ranch conservation easement will help create a contiguous block of nearly 3,000 acres of Ag + Open Space-protected farms and ranches.
Diamond W Ranch is home to a large dairy farm on one side of Valley Ford Road and a large grazing property on the other, with four certificates of compliance and one additional legal lot. Some of these lots may be subdividable. Prior to and as a condition to closing on the conservation easement purchase, the owners must submit an application to merge the Property into two legal lots, each of which is of sufficient size and agricultural utility to host viable and independent agricultural operations.
Diamond W Ranch has strong agricultural values with rolling to steep terrain; productive agricultural soils, including prime soils and soils of statewide importance; ample water sources; a mild climate and good forage production; and could support a wide variety of agricultural operations. Diamond W Ranch is located along two major thoroughfares with easy access to major markets. The Property has long been used as an organic dairy.
Diamond W Ranch contains several drainages into the Estero/Americano Creek and the Stemple Creek watersheds. Both creeks are considered by the State of California to be impaired waterbodies with water quality impacts related to sediment from development and agriculture. The water from this ranch flows to the Estero de San Antonio and Estero Americano, both providing rare coastal habitat for waterfowl and nursery habitat for several commercial and recreational fisheries species. The Esteros are both included in the Gulf of the Farallones National Marine Sanctuary and are a state Marine Recreational Management Areas. The continued careful stewardship of the drainages on this property is important for the long-term recovery goals of the two watersheds.
The Property also contains a large block of land that is federally designated critical habitat for the endangered California tiger salamander. It also contains a well-vegetated farm pond/reservoir that provides agricultural water as well as habitat for waterfowl and amphibians.
Project Structure
The conservation easement will protect the Property’s agricultural, natural, and scenic resources. Agricultural and scenic values will be protected by merging all legal lots into two lots - one on each side of Valley Ford Road. The conservation easement will also limit most development to building envelopes, which will comprise no more than 50 acres. The building envelope on the northern parcel is approximately 39.55 acres and surrounds the existing residential and dairy buildings. Up to two building envelopes, comprising no more than 10 total acres, are permitted on the southern parcel. These envelopes must be sited to minimize impacts to the natural resource, agricultural, and scenic values of the Property. A primary residence will be permitted on each parcel and will be limited to 3,000 square feet.
All agricultural practices that are legal and consistent with agricultural conservation are permitted by the conservation easement, with some limitations. Agriculture in the designated natural areas surrounding the drainages and creeks on the Property is permitted only in accordance with a management plan designed to protect and enhance the natural resources. Additionally, within federally designated critical habitat, agricultural uses that could harm protected species or impair their habitat are prohibited.
Because of the importance of Estero/Americano and Stemple creeks as habitat and for fisheries health, the conservation easement designates “Natural Areas,” comprising a large riparian setback on a small branch of Estero Creek and a 50-foot buffer around the remaining drainages to protect and enhance the riparian areas’ water quality, natural resources, and ecological functions. The landowner may continue to use the Natural Areas for grazing cattle and other low-impact agricultural uses, subject to a management plan describing how they will manage the Natural Areas for the protection and enhancement of the ecological function, water quality, and wildlife habitat function of those areas.
Conformance with Adopted Plans
Vital Lands Initiative
The Diamond W Ranch project furthers Ag + Open Space’s Vital Lands Initiative by protecting lands that support diverse, sustainable, and productive agriculture; natural lands and aquatic habitats that support sustainable aquatic ecosystems and water resources; and natural lands and terrestrial habitats that support plants, wildlife, and biodiversity.
Sonoma County General Plan 2020
The Project furthers several goals and policies in Sonoma County’s General Plan 2020, specifically in the Land Use, Open Space and resource Conservation, Agriculture, and Water Resources elements, as noted in, but not limited to, the following:
• Preservation of lands currently in agricultural production and lands with soils and other characteristics that make them potentially suitable for agricultural use. Retain large parcel sizes and avoid incompatible non-agricultural uses. (Goal LU-09)
• Preserve roadside landscapes that have high visual quality (OSRC-03)
• Preserve the unique rural and natural character of Sonoma County (OSRC-06)
• Protect and enhance the County’s natural habitats and diverse plant and animal communities (Goal OSRC-07)
• Protect and enhance Riparian Corridors and functions along streams, balancing the need for agricultural production… and other land uses within the preservation of riparian vegetation protection of water resources, flood control, bank stabilization, and other riparian functions and values (OSRC-8)
• Encourage conservation of soil resources to protect their long-term productivity and economic value (OSRC-10)
• Protect, restore, and enhance the quality of surface and groundwater resources (WR-01)
• Protect existing groundwater recharge areas (Objective WR 2.3)
• Reduce economic pressure for conversion of agricultural land to non-agricultural use (Objective AR-2.4)
• Maintain the maximum amount of land in parcel sizes that a farmer would be willing to lease or buy for agricultural purposes (Goal AR-03)
Ag + Open Space’s Expenditure Plan
The Project is consistent with the Ag + Open Space Expenditure Plan because it preserves agricultural land uses, biotic habitat areas, and scenic landscape units.
Appraisal and Fiscal Oversight Commission
An appraisal of the Property by Wayne Harding was completed on April 22, 2026. The appraised value of the conservation easement as of January 30, 2026, was $3,395,000. The Sonoma County Open Space Fiscal Oversight Commission reviewed the appraisal on June 4, 2026, and determined by resolution number 2026-007 that (1) the appraisal meets the District’s Appraisal Guidelines and Standards, and (2) completing the proposed acquisition for a purchase price not-to-exceed the opinion of value set forth in the appraisal does not result in the District paying more than the fair market value for the acquisition of such interests.
Purchase Agreement and Purchase Price
The General Manager proposes to purchase the conservation easement for the appraised value of $3,395,000. The purchase agreement with the landowner also requires the landowner submit all necessary paperwork to accomplish a voluntary merger of the Property down to two legal lots (one on each side of Valley Ford Road) and complete a management plan for agricultural use of the Natural Areas prior to the close of escrow.
Escrow/Closing
Close of escrow for the acquisition of the conservation easement is anticipated to occur on or before September 30, 2026, but in no event will it occur later than January 30, 2027.
CEQA
The acquisition of the subject conservation easement is exempt from the requirements of the California Environmental Quality Act (Public Resources Code Sections 21000 et seq.) pursuant to Public Resources Code Section 21080.28(a)(1)(A) & (C) and Cal. Code of Regs. Tit. 14, § 15325(a) & (b)), which exempts from CEQA the acquisition, sale, or other transfer of interest in land by a public agency for the preservation of the natural condition of the property including plant and animal habitats; restoration of natural conditions including plant and animal habitats; for continuing agricultural use of the land; and preservation of open space. Alternatively, it is exempt pursuant to Section 15317 of Title 14 of the California Code of Regulations, because the purpose of the acquisition is to maintain the open space character of the area.
Dedication
Consistent with Ag + Open Space practice, the Board is asked to dedicate the conservation easement to open space purposes pursuant to Public Resources Code Section 5540. By taking this action, Ag + Open Space is restricting its ability to convey or relinquish the protections embodied in the conservation easement.
Strategic Plan:
n/a
Racial Equity:
n/a
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No.
Prior Board Actions:
n/a
Fiscal Summary
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Expenditures |
FY 26-27 Adopted |
FY 27-28 Projected |
FY 28-29 Projected |
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Budgeted Expenses |
$3,395,000 |
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Additional Appropriation Requested |
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Total Expenditures |
$3,395,000 |
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Funding Sources |
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General Fund/WA GF |
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State/Federal |
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Fees/Other |
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Use of Fund Balance |
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Contingencies |
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APOSD Measure F funds |
$3,395,000 |
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Total Sources |
$3,395,000 |
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Narrative Explanation of Fiscal Impacts:
Ag + Open Space has adequate appropriations in its FY 26-27 budget for the $3,395,000 conservation easement acquisition, which is funded by Sonoma County voter-approved Measure F.
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Staffing Impacts: |
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Position Title (Payroll Classification) |
Monthly Salary Range (A-I Step) |
Additions (Number) |
Deletions (Number) |
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n/a |
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Narrative Explanation of Staffing Impacts (If Required):
n/a
Attachments:
1. Resolution
2. General Plan Map 2020
3. Site Map
4. Notice of Exemption
5. Conservation Easement
6. Certificate of Acceptance
Related Items “On File” with the Clerk of the Board:
n/a