TO: HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL
FROM: David Chantarangsu, AICP, Development Services Director
PREPARED BY: Chris Tracy, Senior Planner, Advanced Planning
SUBJECT:
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Introduction of an Ordinance Concerning the Hillside Development Standards (DCA-2021-2396) to Amend the Murrieta Municipal Code (Titles 8 and 15), Chapters 8.20, 15.52, and to Amend Murrieta Development Code (Title 16) for the Purpose of Revising and Updating Chapters 16.08, 16.14, 16.18, 16.22, 16.24, 16.28, and Adding New Sections 16.24.080, Entitled “Exceptions,” 16.24.090, Entitled “Reserved,” and 16.24.100, Entitled “Hillside Overlay Map”
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ABSTRACT
Since 2022, the City has undertaken a comprehensive update of its hillside regulations to establish more objective hillside development standards and to clearly define the geographic areas where those standards apply. The amendments included in the proposed Ordinance clarify slope, building height, retaining walls (updates limited to hillside areas), landscaping, and fuel modification standards, while improving predictability for property owners and applicants. Staff also incorporated a threshold for minimal development. The draft ordinance states that development that requires grading less than 50 cubic yards would not be subject to a zoning application but would be reviewed administratively, potentially saving applicants significant time and money. Council may wish to increase this threshold to a range between 200 to 500 cubic yards.
RECOMMENDATION
recommendation
Open the Public Hearing;
Receive public testimony;
Find that the proposed ordinance is consistent with standards originally evaluated and implemented pursuant to the Negative Declaration adopted for implementation of the Comprehensive Development Code on October 28, 1997, and that the proposed updates are consistent with the Murrieta General Plan Final Environmental Impact Report (FEIR) and Supplemental Environmental Impact Report (SEIR) certified by the City of Murrieta in 2021 (SCH No. 2010111084) in accordance with Public Resources Code Section 21166 and CEQA Guidelines Section 15162; and
Conduct the first reading and introduce Ordinance No. 638-26 entitled: An Ordinance of the City Council of the City of Murrieta, California, to Amend the Murrieta Municipal Code (Titles 8 and 15), Chapters 8.20, 15.52, and to Amend Murrieta Development Code (Title 16) for the Purpose of Revising and Updating Chapters 16.08, 16.14, 16.18, 16.22, 16.24, 16.28, and to Add New Sections 16.24.080, Entitled “Exceptions,” 16.24.090, Entitled “Reserved,” and 16.24.100, Entitled “Hillside Overlay Map.
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PRIOR ACTION/VOTE
Please see the Discussion Section of this report.
STRATEGIC ALIGNMENT
This item aligns with the City Council goal to maintain a high performing organization that values fiscal sustainability, transparency, accountability and organizational efficiency. Updating the Hilliside Ordinance is a Tier 1 priority project.
DISCUSSION
The City adopted its first General Plan in 1994, following incorporation in 1991. Until the adoption of its own zoning regulations, the City continued to rely on Riverside County Ordinance No. 348 (Zoning), provided those regulations did not conflict with the General Plan. Following public workshops and a comprehensive code development process beginning in 1996, the City adopted its Development Code in early 1998, replacing the County’s regulations. The Development Code, contained in Title 16 of the Murrieta Municipal Code (MMC), serves as the primary tool for implementing the General Plan and includes hillside development standards. Except for minor amendments in 2003, these standards have remained largely unchanged.
When adopted, the hillside standards applied citywide rather than to specifically designated hillside areas. A hillside features map was later developed and used during project review; however, it was never codified in the MMC, and questions have remained regarding its accuracy and application. Advances in Geographic Information System (GIS) technology now allow the City to objectively identify and map hillside areas using reliable topographic data. In addition, inconsistencies within the Development Code, particularly regarding slope and building height, have contributed to inconsistent application of the standards giving rise to concerns from applicants about the complexity and inconsistent application of the standards.
In response, the City Council directed staff at its March 29, 2022, annual priority goal setting workshop to review the hillside development standards contained primarily in MMC Chapter 16.24, “Hillside Development.” The proposed amendments are intended to modernize and clarify these regulations by resolving code inconsistencies, establishing more objective and predictable standards, incorporating current technology and best practices, and improving usability for applicants and staff.
It should be noted that, as part of the City’s extensive public outreach efforts since 2022, the proposed hillside development standards have been discussed and refined through numerous public meetings and workshops. These efforts have included a community workshop at Alderwood Park, three (3) Planning Commission workshops, three (3) Planning Commission public hearings, and six (6) City Council workshops, providing multiple opportunities for public input throughout the development of the updated standards. Collectively, these meetings have provided numerous opportunities for residents, property owners, applicants, and other interested parties to review the proposed changes, provide feedback, and participate in developing the updated standards. Public input received throughout this process has helped inform and refine the proposed amendments, including revisions intended to address community concerns and to provide a framework for clearer, more objective, and consistently applied hillside development regulations.
The primary objective of these updates is to modernize the City’s hillside development regulations by replacing outdated formulas and subjective criteria with clear, objective, and consistently applied standards. Using modern GIS technology, the City has established a formal Hillside Overlay Map (Attachment 3) that clearly identifies where hillside regulations apply. This approach ensures that the hillside development standards, including the 25 percent slope threshold, are applied only within designated hillside areas, rather than citywide, which was never the intent of the regulations, according to Council verbal direction at the 2022 Council Priority Goals Workshop.
The proposed amendments also include several technical refinements intended to improve administrative efficiency, regulatory clarity, and project predictability for both applicants and City staff. Key changes include establishing a standardized methodology for measuring building height on sloped properties; replacing manual average-slope calculations with GIS-based data; and providing a Computer-Aided Drafting (CAD) based alternative when an applicant disputes the City’s GIS determination. The amendments also clarify standards for retaining walls in hillside areas, landscaping, and fuel modification requirements to address fire safety while minimizing impacts on the natural terrain.
Through this review process, the City Council directed that a comprehensive update to citywide retaining wall regulations be addressed through a separate future ordinance. The current hillside criteria amendments incorporate enhanced design standards intended to reduce the visual impact of retaining walls in hillside areas. These provisions include the use of muted, earth-tone colors, terraced wall configurations, and landscaping between wall terraces where feasible. Collectively, the amendments provide a more transparent and predictable regulatory framework while balancing future development opportunities, public safety, and preservation of the City’s natural hillside character.
Planning Commission Additions
At the Planning Commission’s public hearing on July 8, 2026, staff brought forward suggested thresholds to identify when a property owner must file a zoning application and pay a fee for review by the Planning Division, verses an administrative process. While public comments have been made throughout this process about various circumstances that might trigger the need for a zoning application, no specific direction has been provided. Staff suggested the Planning Commission consider three scenarios that could be used to determine when a zoning application would be required. The approach involves adding the following definitions to the City’s hillside regulations:
• Agricultural Use;
• Developed/Disturbed; and
• Undeveloped/Undisturbed.
These distinctions recognize that prior physical alteration of a site may affect the applicability and level of hillside development review needed. Each is described in more detail below.
• Agricultural Use - “Developed” as it relates to a disturbed hillside area condition does not include agricultural uses or improvements customarily associated with agricultural operations, including but not limited to crop cultivation, grazing, orchards, vineyards, irrigation systems, fencing, or agricultural access roads. The installation or maintenance of such agricultural improvements shall not, by itself, cause a hillside area to be considered “developed” for purposes of this Chapter.
• Developed/Disturbed - Means land that has been altered from its natural state through grading, excavation, fill placement, construction, paving, landscaping, or installation of infrastructure improvements.
• Undeveloped - Means land within a hillside area that remains in a substantially natural state and has not been significantly altered by grading, construction, paving, or installation of infrastructure improvements.
In the proposed ordinance, Table 16.24-1 has been added to address these new criteria. The following information summarizes the table’s requirements:
• Undeveloped/Natural Areas: Continue to require a Hillside Development Plan Permit and remain subject to applicable grading requirements.
• Previously Developed Areas: Minor improvements within legally developed or disturbed portions of a site may be exempt from a Hillside Development Plan Permit when grading does not exceed 50 cubic yards, including improvements such as flatwork, pools, and spas.
• Determining Developed Status: Prior development may be demonstrated through grading or building permits, certificates of occupancy, and approved grading plans. Where records are unavailable, historical aerial imagery may be considered by the Development Services Director, with disputed determinations referred to the Planning Commission.
• Agricultural Areas: Agricultural activities and customary agricultural improvements do not, by themselves, cause a hillside area to be classified as “developed.”
• Grading and Drainage: Grading exceeding 50 cubic yards and fine grading/drainage activities remain subject to applicable Engineering review and permitting requirements under MMC Chapter 15.52.
• ADUs and Accessory Structures: ADU processing remains governed by State law, including tolling for required discretionary approvals. Accessory structures of 1,000 square feet or greater require a Hillside Development Permit.
• Hillside Design Standards: All development within a designated Hillside Area remains subject to applicable hillside design standards, regardless of whether the affected portion of the property is developed or undeveloped.
It’s important to note that in situations where a Hillside Development Permit (zoning application) is not required, the slightly elevated standards included in the Hillside Ordinance still apply. However, those standards would be applied during grading and/or building permit review and would not require the more extensive review associated with a zoning application.
Increasing the Threshold for Requiring a Hillside Development Permit
Within the draft ordinance the City’s current Hillside Development Permit standards use 50 cubic yards of grading as a threshold for determining when certain hillside activities require additional discretionary review. For context, 50 cubic yards is approximately equivalent to the volume of dirt that would fill one typical residential swimming pool.
As part of this Hillside Development Code update, the City Council may wish to consider whether the existing 50 cubic yard threshold remains an appropriate trigger for requiring a Hillside Development Permit, or whether the threshold could be increased to 200 cubic yards (approximately four swimming pools of dirt) or another amount. The intent with these regulations would be to identify a threshold that allows relatively minor grading or earthwork activities to proceed without the additional time, cost, and discretionary review associated with a Hillside Development Permit, while continuing to ensure that activities with the potential to materially affect hillside character, landform, or visual resources remain subject to appropriate review.
In considering a potential increase, the key policy question is whether a greater volume of earthwork can reasonably be accommodated without creating significant visual or physical changes to a hillside area. A revised threshold could provide greater flexibility for modest improvements while maintaining the Hillside Development Permit process for projects of a scale or intensity that warrants closer review.
Potential approaches to include in the Final Ordinance (Attachments 4 through 7):
• Option 1 - Maintain 50 cubic yards as drafted in Ordinance - Retains the existing, more conservative threshold and provides greater oversight of relatively small grading activities.
Visually, the following is a representation of this:
• Option 2 - Increase to 200 cubic yards - Approximately equivalent to four (4) residential swimming pools and would allow more modest grading activities to occur without automatically triggering a Hillside Development Permit.
For Comparison Purposes:
o City of Tustin: Hillside projects involving less than 200 CY of cut/fill can be treated as “minor” hillside review and approved administratively by the Community Development Director. Projects not considered minor go to the Planning Commission.
Visually, the following is a representation of this:
• Option 3 - Establish another threshold - Council could select an intermediate or higher threshold based on the desired balance between administrative flexibility, property improvements, and protection of hillside resources.
For Comparison Purposes:
o City of Lake Forest: 500 CY on a building site with slopes greater than 15% is subject to approval of a Site Development Permit.
o City of Laguna Hills: 500 CY on a building site with slopes greater than 15% is subject to approval of a Site Development Permit, or the proposed project requires movement of five thousand 5,000 CY of earth regardless of slope.
o City of Los Angeles: Hillside grading is subject to specialized grading requirements. Excavation or fill of 250 CY or more in a hillside area triggers a grading bond requirement.
Conclusion
In conclusion, the proposed amendments represent the culmination of a multi-year effort to modernize hillside development regulations that have remained largely unchanged for nearly three decades. Building upon extensive public input and direction from the City Council and Planning Commission, the updated framework is intended to replace outdated, ambiguous, and potentially inconsistent provisions with clearer, more objective, and more predictable standards.
The use of GIS-based mapping will further ensure that hillside regulations are applied to areas where hillside conditions are present, rather than through a citywide regulatory framework that may unnecessarily affect properties without meaningful hillside constraints. Collectively, the proposed amendments seek to preserve the original purpose and intent of the City’s hillside regulations by protecting public safety, environmental resources, hillside character, and visual quality, while providing a more transparent, efficient, and consistently administered regulatory framework for property owners, applicants, the public, and City staff.
While no regulatory framework can anticipate every circumstance or achieve perfection at the outset, the proposed amendments provide a sound and practical foundation for moving forward. Importantly, the updated regulations incorporate a built-in appeals process, providing an additional procedural safeguard and a mechanism to address disagreements or unique circumstances that may arise in interpreting or applying the updated standards.
As the regulations are implemented, staff will also have the opportunity to evaluate how they function in practice and identify any unforeseen issues, unintended consequences, or areas where additional clarification may be warranted. Should broader or recurring issues emerge, the City Council retains the ability to revisit and further refine the regulations. In this respect, the proposed amendments establish a workable framework that can be implemented now, evaluated through real-world application, and adjusted over time as necessary to ensure the regulations continue to achieve the City’s hillside development objectives and remain consistent with the General Plan’s Goals and Policies related to hillside development.
PUBLIC NOTICING
A notice of public hearing for this item was published in the Press Enterprise on September 4, 2026.
CEQA AND REGULATORY OVERVIEW
The proposed action was previously reviewed for consistency with the Citywide Comprehensive Development Code in 1998. The standards were originally evaluated and implemented pursuant to the Negative Declaration adopted for implementation of the Comprehensive Development Code on October 28, 1997. Furthermore, the proposed updates have been evaluated for consistency with the current project proposal in consideration of the previously adopted Negative Declaration and the Murrieta General Plan Final Environmental Impact Report (FEIR) and Subsequent Supplemental Environmental Impact Report (SEIR) certified by the City of Murrieta in 2021 (SCH No. 2010111084) in accordance with Public Resources Code Section 21166 and CEQA Guidelines Section 15162.
Based on this evaluation, staff determined that the proposed updates would not result in significant new environmental impacts, a substantial increase in the severity of previously identified impacts or changed circumstances that would require preparation of a subsequent or supplemental environmental document. Accordingly, the previously adopted environmental documents adequately address the proposed modifications (Attachments 9 and 10).
FISCAL IMPACT
Should the City Council create an exemption threshold for hillside development, there may be a de minimis reduction in permit fee revenue received.
ATTACHMENTS
ATT 1 - Ordinance No. 638-26
ATT 2 - Ordinance Redlines
ATT 3 - Hillside Overlay Map
ATT 4 - 45 Cubic Yard Visual Example
ATT 5 - 50 Cubic Yard Visual Example
ATT 6 - 200 Cubic Yard Visual Example
ATT 7 - 200 Cubic Yard Visual Example with Home Office
ATT 8 - Hillside Updates City Council Public Notice
ATT 9 - 15162 Consistency Analysis
ATT 10 - 15162 Draft Notice of Determination (NOD) - Subsequent Action
ATT 11 - Riverside County Airport Land Use Comm (ALUC) Approval Letter - 8-27-26