FAQs: Clustering and Density Bonus Programs in South Livermore Valley

On May 8, 2025, the Board of Supervisors adopted resolution R2025-237 approving and adopting general plan amendments to the East County Area Plan to promote development of visitor-serving uses supporting the South Livermore Valley Area , conducted the First Reading of an ordinance amending Section 17.30.170 of the Alameda County General Ordinance Code - Zoning, pertaining to the development of visitor-serving commercial uses in the CA (Cultivated Agriculture) Combining District, and adopted an Addendum to the 1993 Environmental Impact Report for the South Livermore Area Specific Plan as the appropriate CEQA document to address the proposed amendments. The Board conducted a second reading and adopted the Zoning Ordinance amendments on June 12, 2025.

The primary impact of the approved amendments is to allow for the clustering of buildings on parcels in the A-CA zoning district of South Livermore Valley to facilitate the development of visitor-serving commercial facilities to encourage tourism in the area to support a thriving wine industry and encourage the expansion of vineyards and other cultivated agriculture.

The following guidance is intended to assist applicants who are considering pursuing a clustering plan under the new rules:

Where can I find the regulations associated with clustering plans and the density bonus program in the South Livermore Valley "Cultivated Agriculture" (CA) combining district?

East County Area Plan Program 34 and Program 141
Alameda County Code of Ordinances - Zoning section 17.30.170, as amended by Ordinance No. 2025-33

What is the new clustering plan program?

East County Area Plan Program 34 and Program 141
In brief, the new clustering program allows development in the CA Combining District of the South Livermore Valley to be grouped into flexible, combined building envelopes that occupy up to 10% of the clustered land. The clustering plan program creates regulatory conditions that were intended to promote visitor-serving commercial uses and support the agricultural economy in the South Livermore Valley.

What Planning approvals are required for a clustering plan?

A clustering plan requires a Site Development Review (SDR), subject to approval by the Planning Director
Visitor-serving commercial uses on parcel(s) require a Conditional Use Permit (CUP), subject to approval by the Board of Zoning Adjustments
Where both an SDR and a CUP are required, no separate SDR application is required. Disapproval of either constitutes disapproval of the application. (17.54.160 - Conditional uses-Combined applications.)

How do I initiate a Site Development Review or Conditional Use Permit process for a clustering plan?

Create an account in Alameda County's Permit Portal and log in
Click Planning Permits and Apply Now
Select Type > Planning Case
Select Sub-Type > Site Development Review OR Conditional Use Permit, as applicable to your project
Follow prompts to complete application, provide supplemental materials, and submit payment
For more details about the SDR and CUP approval process, reference the Supplemental Guides provided in the Permit Portal

Does a clustering plan require subdivision?

No. An applicant is not required to subdivide any parcel in order for the County to approve a clustering plan (Alameda County Code of Ordinances section 17.30.170(H)). A density bonus without clustering requires subdivision.

What is the smallest parcel size that could be allowed in the CA Combining District, either under a density bonus or a clustering plan?

20 acres is the smallest parcel size that could be allowed under the density bonus program or a clustering plan.

Would the County consider granting a variance to change the maximum dwelling unit density or minimum building site area?

No. The new clustering plan provisions specifically prohibit approval of a variance of the provisions of Section 17.30.170 that set the maximum dwelling unit density; the minimum building site area, and the maximum amount of land that may consist of environmentally sensitive areas (17.30.170(H)).

What are the requirements for conservation easements under a clustering plan vs a traditional density bonus?

Clustering plan: The entirety of all parcels within a clustering plan must be placed under a permanent agricultural conservation easement.
Density bonus without a clustering plan: The applicant must demonstrate and guarantee that a minimum of ninety (90) percent of the area of the parcel being subdivided will be permanently set aside for viticulture or other cultivated agriculture. This is typically done via a conservation easement.

How do planting requirements differ between a density bonus with clustering and a traditional density bonus (without clustering)?

Without clustering: Where a density bonus is applied without a clustering plan, a minimum of ninety (90) percent of the area of the parcel being subdivided must be permanently set aside for viticulture or other cultivated agriculture, planted, and maintained for a minimum of eight years in wine grapes or other cultivated agriculture.
With clustering: Where a clustering plan is applied, no less than 90% of the acreage of the parcel or parcels on which any visitor-serving commercial uses are located shall be planted and maintained in cultivated agriculture for as long as those visitor-serving commercial uses are in operation; however, parcels within a clustering plan that do not contain a visitor-serving commercial use in operation are not required to be planted and maintained in cultivated agriculture(ECAP Program 141). In both cases (visitor-serving commercial uses or residential only uses), a permanent agricultural conservation easement is required (see question 8, above).

Does a clustering plan need to include commercial uses?

No, a clustering plan is not required to include commercial uses. However, the intent of the clustering plan provisions approved by the Board of Supervisors in Ordinance No. 2025-33 was to promote development of visitor-serving uses and economically sustainable agricultural operations in the South Livermore Valley.

If I apply for a clustering plan for residential development only (i.e. no commercial use) on the clustered parcels, is there a planting requirement?

No. Parcels within a clustering plan that do not contain a visitor-serving commercial use in operation are not required to be planted and maintained in cultivated agriculture. However, the entirety of all parcels within a clustering plan must be placed under a permanent agricultural conservation easement. (ECAP Program 141)

If I apply for a density bonus to subdivide to 20 acres but am not part of a clustering plan, is there a planting requirement?

Yes. 17.30.170.5 requires that a minimum of ninety (90) percent of the area of the parcel being subdivided be permanently set aside for viticulture or other cultivated agriculture, planted, and maintained for a minimum of eight years in wine grapes or other cultivated agriculture, except for minor portions needed to preserve environmentally sensitive areas or undeveloped parcels in the subdivision that are subject to a clustering plan. In both cases (visitor-serving commercial uses or residential only uses), a permanent agricultural conservation easement is required (see question 8, above).

How does a Williamson Act contract impact a clustering plan application?

Where clustering plans are applied to parcels under Williamson Act Contract, proposed development must also comply with the Alameda County's Uniform Rules and Procedures Governing Agricultural Preserves and Williamson Act Contracts ("Uniform Rules") and the existing Williamson Act Contract. For example:
The County will not approve applications for non-agricultural uses on contracted land, including use permits, development permits, Site Development Review, or subdivisions, unless there is an existing agricultural use that meets one of the commercial agricultural thresholds established in Rule 1 of the County's Uniform rules.
Owners of existing contracts seeking permits for a new use allowed under the contract are subject to the Compatible Use Determination process described under Section III of County's Uniform rules. However, unless there is an existing agricultural use that meets one of the commercial agricultural thresholds established in Rule 1 of this document, the County will not approve applications for non-agricultural uses on the contracted land.
Any proposed new use must be in an appropriate scale with the primary agricultural use so as to be considered incidental to the primary agricultural use.
For a landowner to qualify as devoted to the commercial production of agriculture and maintain eligibility under the contract, the contracted land must meet minimum annual revenue requirements and land coverage requirements outlined in Uniform Rule 1.
The residential uses permitted on contracted land are more restrictive than those authorized by the underlying zoning districts. For example:

Residential dwelling units are considered an allowable compatible use only when occupied by the owner, the owner's immediate family, agricultural employee(s), seasonal farm laborers, or caretakers.
Residential dwelling units may be rented only to those involved in the primary agricultural use on the property. Vacation rentals are not permitted, excepting limited Bed and Breakfast (B&B) operations in the South Livermore Valley Plan Area
One single-family dwelling unit (as defined in Section 17.06.030 A. of the Zoning Ordinance), with residential accessory uses, is allowed on the whole of the contracted land. At least one occupant of the dwelling unit must be the owner, the owner's immediate family, agricultural employee(s), or caretaker(s).

How do I cancel or non-renew a Williamson Act contract?

The process for cancelling or non-renewing a Williamson Act contract is outlined in the County's Uniform Rules, Rule 5.