Accessory Dwelling Units

Accessory Dwelling Unit Service Page Photo


Advisory Regarding Water Availability

Given current water supply and demand projections and the SAFE Water Supplies Ordinance approved by the Voters of the District in 1991, the District’s Board of Directors adopted Resolution 2014-32 directing the denial of applications for new or expanded water service commencing October 1, 2014. The current prohibition applies to Accessory Dwelling Units (ADU) that involve new ADUs built at the same time as a new Single-Family Dwelling (SFD) on properties with water credit that is not sufficient to support the proposed annual demand. However, construction of new ADUs or the conversion of existing structures to create an ADU where a primary dwelling unit already exists on the parcel are not subject to the prohibition. It is highly recommended that property owners considering an ADU project contact the District early in their planning process to confirm the availability of water for the proposed project.

The District provides expedited review for proposed ADUs, and Junior ADUs (which are smaller habitable dwellings up to 500 square feet located entirely within a primary SFD). ADUs may be detached or attached to a primary dwelling or accessory structure on residentially zoned properties.

The following is a summary of steps for obtaining approval of water service for a new ADU:

Step 1 – Determine Water Availability

A. New ADUs or Conversion of existing structures to an ADU where a Single-Family Dwelling (SFD) exists

The District Code allows that no New Water Supply Charge shall be assessed for the establishment of an Accessory Dwelling Unit where there is an existing SFD on the parcel. Projects involving ADUs with an existing SFD are exempt from water demand analysis and thus may be permitted during the current prohibition.

B. Projects involving new structures or additions concurrent with construction of a new SFD

ADU projects that are proposed at the same time as a new SFD structure are subject to water demand analysis to confirm water availability. Upon the property owner’s request, District Water Supply and Conservation (WSC) staff will review District records and provide an overview of any quantified water entitlements available for a parcel. WSC staff can also provide a general indication as to whether the existing entitlements are adequate to allow for a new ADU. However, for projects that could result in annual water use that exceeds the historical credit, the property owner may choose to have their qualified engineer prepare an annual water demand estimate for existing and proposed development for District review.

The ADU projects proposed at the same time as a primary SFD are subject to a determination of adequate water availability and the current prohibition on new or expanded service when there are not adequate pre-existing entitlements. Proposed projects or uses that fall within one of the exceptions specified in the SAFE Ordinance are exempt from the annual demand evaluation step in the application process. The District must deny projects that would increase annual water demands beyond pre-existing entitlements. Applicants may re-apply at a future date when new water becomes available for allocation by the District. New Water Supply Charges for new allocations will apply.

C. Junior ADUs

Junior ADUs are not subject to New Water Supply Charge except that when both the Junior ADU is to be constructed with a new single-family dwelling and the New Water Supply Charge calculation is not based upon the Junior ADU being a separate dwelling unit from the primary dwelling unit, then a New Water Supply Charge shall be assessed.

Step 2 – Request Preliminary Water Service Determination

If it is determined that a parcel has adequate water entitlements for a new ADU, the Property Owner may request a Preliminary Water Service Determination (PWSD). In addition to the determination of water availability described above, it may be necessary for the District to review private water system information to evaluate the adequacy of the meter and service line size. District staff will advise if this is required, depending on the project description.

The District PWSD will confirm for the applicant and County or City: 1) the project description reviewed by the District, 2) whether the project has adequate water available to proceed, and 3) whether a District application for water service is required. A PWSD is generally required by local land use agencies prior to processing applications a land use permit or permit exemption. The District recommends property owners obtain a PWSD for all development projects including ADUs.

A. Separate Meter Requirement

ADU projects involving conversion of existing structures and new construction not exceeding 150 square feet may use the same meter as the primary SFD. Projects involving new ADUs concurrent with new primary SFDs and projects involving conversion of an accessory structure with additions exceeding 150 square feet beyond the same physical dimensions of the existing structure are required to have a separate meter for the new ADU. The meter may be either a District meter or a private sub-meter. (For a District meter, see Step 3.)

A separate meter is not required for a Junior ADU, which is located entirely within the SFD.

B. Evaluation of Meter Size for a private sub-meter or where a Separate Meter is not required

A separate District meter is not required for accessory structures, including residential second units, where the existing meter size is adequate to serve the primary uses and the new ADU, as well as any fire protection sprinkler systems. In order to evaluate the adequacy of the existing meter and service, the District will review the following, as applicable:

  1. Fixture and Appliance Unit Count Summary
  2. Fire Sprinkler Calculations
  3. Irrigation System Calculations
  4. Complete project description including square footages of existing and proposed structures as well as project site, floor and landscape plans (if available)

C. Cross Connection Survey – Backflow Requirement

Applicants must submit a Cross Connection Survey Form with each application or PWSD request. If the District determines that the private system poses a risk of hazard to the public water system, a backflow prevention assembly will be required.

Step 3 – Apply for Changes to Water Service or Separate Meter (Where Applicable)

A full water service application will be necessary if changes to the public water system are required. This may be the case if the District determines that changes to the existing service line or meter are necessary to accommodate the ADU or changes service requirements, including addition of fire sprinkler systems or if the property owner requests a separate meter. Please see the District Outline of Application Process for Water Service for additional information. Note that the physical water delivery system, including shared or separate meters, does not factor in the forecasted water demand determination.

Please contact the District at 805-964-6761 with any questions or for additional information regarding ADUs or the District application process for water services.

Click here to download the Goleta Water District Summary of Process for ADUs PDF.