Ross Municipal Code § 18.39 Referenced Standards

18.39.010 Purpose. 18.39.020 Chapter application. 18.39.030 Submittal requirements. 18.39.040 Review authority and notice requirement. 18.39.060 Approval--Special conditions and findings. 18.39.090 Hillside lot design regulations and guidelines. 18.39.100 Noncompliance. 18.39.120 Variances.

18.39.005 Title. This ordinance shall be known and may be cited as the Hillside Lot Ordinance. (Ord. 620 (part), 2010).

18.39.010 Purpose. The purpose of this chapter is as follows:

(a) Ensure that development is consistent with the goals, policies and criteria of the general plan;

(b) Protect and preserve public and private open space as a limited and valuable resource;

(c) Preserve significant features of the natural environment including watersheds, watercourses, canyons, knolls, ridgelines and rock outcroppings and minimize disturbance to the natural terrain;

(d) Protect steep slopes, creeks, significant native vegetation, wildlife and other environmental resources;

(e) Limit development to a level consistent with available public services and road access that can be reasonably provided to and within the parcel;

(f) Ensure that development will not create or increase fire, flood, slide or other hazards to public health and safety;

(g) Protect the public health, safety and general welfare and the property of people in the vicinity of steep hillside building sites;

_____________ * Prior ordinance history: Ords. 413, 430, 435, 440 and 472.

(h) Ensure that development will not create or increase the potential of major financial loss to the town or any other governmental entity through claim or litigation related to physical development of the site.

(i) Reduce the visual impacts of construction on hillsides and encourage building designs compatible with hillside areas.

This chapter establishes procedures and standards for the review of land divisions and the construction of buildings, structures and improvements necessary to meet this purpose. (Ord. 620 (part), 2010; Ord. 521 (part), 1993).

18.39.020 Chapter application.

(a) This chapter shall apply to hillside areas. Hillside areas are defined as parcels which have a slope of thirty percent or greater or are wholly or partially within Hazard Zones 3 or 4 as identified on the town slope stability map. An application for a hillside lot review is required for any development or subdivision of a hillside lot.

(b) A hillside lot application is also required on improved parcels having thirty percent or greater overall natural or building site slope, or containing Hazard Zones 3 or 4, for the following projects and for staged, phased or cumulative improvements that exceed these thresholds:

(1) All new buildings, building relocations, and for all exterior remodeling resulting in additions, extensions or enlargements to existing buildings exceeding two hundred square feet of new floor area, including enclosing existing open areas;

(2) The construction of any retaining wall greater than forty eight inches in height as measured from bottom of footing to top of wall or any terraced retaining walls totaling more than forty-eight inches in height;

(3) Retaining walls totaling more than one hundred linear feet;

(4) Any activity or project resulting in more than fifty cubic yards of grading or filling, whether or not a building permit is required;

(5) Any construction, improvements, grading/filling or other site work within twenty-five feet of the top bank of a creek, waterway or drainageway, whether or not a building permit is required; and

(6) For any project on a lot that previously received a hillside lot application

approval.

(7) A hillside lot application is not required for an attic improvement permitted under Chapter 18.46 or a basement improvement under Chapter 18.45 unless the project involves exterior work within twenty-five feet of a creek, waterway or drainageway, or if the attic or basement project is associated with a larger project that requires a hillside lot permit.

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(c) A hillside lot application is also required for any land division which has a natural slope or building site slope of thirty percent or greater for any existing or proposed lots.

(d) No building permit for buildings or structures shall be issued for hillside areas, and no map of any proposed subdivision containing hillside areas shall be approved, until a hillside lot application is approved by the town consistent with the requirements of this chapter. (Ord. 704 (part), 2020; Ord. 636 (part), 2012; Ord. 620 (part), 2010; Ord. 611 (part), 2008; Ord. 604 (part), 2008: Ord. 521 (part), 1993).

18.39.030 Submittal requirements. (a) An applicant shall file an application for hillside lot review with the planning department on forms prepared by the Planning and Building Director or their designee. The applicant shall pay a fee as set by the town council.

(b) Every hillside lot application shall include drawings, plans, reports, specifications and graphic or written material as required by the Planning and Building Director or their designee or town council to clearly and accurately describe the proposed work, its effect on the environment and its relationship to existing improvements. Standard submittal requirements will be prepared by the Planning and Building Director or their designee. Such submittals shall include a proposed Erosion Control Plan, and if required by Chapter 12.28 of the town code, a Stormwater Control plan and a Stormwater Facilities Operation and Maintenance Plan. Additional information may be required by the planner or town council. The town engineer will review all applications to determine the appropriate level of geotechnical report necessary to evaluate the safety of the proposed improvement.

(c) Independent evaluation and report by an architect, landscape architect, registered engineer or similarly qualified individual may be required by the Planning and Building Director or their designee or council to assist the town in evaluating the application. This consultant will be selected by the town and retained at the applicant's expense.

(d) Any necessary review by a certified engineering geologist shall include an evaluation of the risk to adjoining property or structures by the proposed development, including the construction of roads and other improvements, or by the condition of the property after development has occurred. The review shall evaluate if the condition of adjacent property indicates any significant risk of future damage to proposed structures. The review shall discuss the need for earth repair to mitigate soils conditions on the site and the effects of this repair on environmental concerns such as vegetation removal or massive grading. (Ord. 728 (part), 2025; Ord. 657 (part), 2014; Ord. 620 (part), 2010; Ord. 521 (part), 1993).

18.39.040 Review authority and notice requirement. The town council shall review the hillside lot applications required by this chapter at a public hearing. At least 10 days prior to the hearing a public notice shall be posted in at least three public places within the town, including the project site, and mailed to the property owner and to all owners of property as shown on the latest equalized assessment roll within 500 feet of the exterior boundary of the property. (Ord. 620 (part), 2010; Ord. 521 (part), 1993).

-- 18.39.060 Approval Special conditions and findings. (a) The town council may approve, conditionally approve or deny an application for hillside lot review. The town council

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shall include conditions necessary to meet the purpose of this chapter and for substantial compliance with the hillside lot design standards set forth in this chapter. The council may adopt by resolution standard conditions for all projects to meet.

(b) The town council shall make the following findings to approve a hillside lot application:

(1) The project complies with the stated purposes of this Chapter;

(2) The project complies with the development regulations of Section 18.39.090, or that the Town Council has considered and approved a variance; and

(3) The project substantially conforms to the hillside development guidelines in Section 18.39.090. (Ord. 620 (part), 2010; Ord. 534 (part), 1996; Ord. 521 (part), 1993).

18.39.090 Hillside lot design regulations and guidelines. This section provides both regulations and guidelines for hillside development. Regulations are identified by use of the term “shall” and compliance is mandatory. Guidelines are identified by use of the term “should” and compliance is not mandatory but is strongly recommended. The Town Council may deny an application where there are substantial inconsistencies with one or more guidelines in a manner that is counter to any purpose of this ordinance.

If any provision of this ordinance is in conflict with another area of the municipal code, the more restrictive regulation, guideline or policy shall apply.

(a) Maximum Floor area. The maximum floor area for lots having thirty percent or greater overall natural slope shall be limited based on the lot slope and lot size using the following formula:

Maximum floor area = (0.15 - 0.002S)A - 0.005 (A² /43,560)

A = lot area in square feet, up to a maximum of 3 acres

S = slope of the lot, up to a maximum of 55%

For example, a 15,000 square foot lot with a slope of 33 percent would be permitted up to 1,234 square feet of floor area.

(b) Building setbacks. Minimum yards shall be provided as follows.

(c) Grading and retaining walls. Grading, cutting and filling and retaining walls should be minimized for hillside development by using building techniques which reflect the natural topography of the site. Applicants should balance cut and fill on site. Graded slopes shall not

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exceed 2:1. Individual retaining walls shall not exceed a height of six feet. Terraced retaining walls should be at least three feet apart to allow for screening vegetation. The aggregate height of retaining walls should not exceed eighteen feet for any particular slope. Upslope walls up to four feet in height may be constructed of pressure-treated timber. All walls up to six feet in height may be constructed of reinforced concrete block. All other walls shall be constructed of reinforced concrete. Visible concrete and concrete block walls should have an appropriate architectural finish.

(d) Architecture.

• (1) Architectural design should complement the form of the natural landscape.

• (2) Designs should be well-articulated to minimize the appearance of bulk.

• (3) Materials and colors should be of subdued tones to blend with the natural

landscape.

(4) Building design and the placement of driveways should conform to the natural contours of the site.

(5) The town council may consider limiting floor area to account for tall wall heights and other volumes that exaggerate the height, bulk and mass of a building but are not included in floor area.

(6) Decks, particularly elevated decks, should enhance the appearance of a house and be of a scale and style which are compatible with the house, adjacent development, and the surroundings. The town council may limit deck and patio area based on considerations of aesthetics, potential for noise, bulk and mass, privacy of adjacent sites, and visibility. The maximum guideline area of decks over 18 inches in height (including car decks) is 25% of the maximum permitted floor area for the site under this chapter.

(e) Landscape Architecture.

(1) Native shrubs and trees should be retained on hillside terrain wherever possible to help reduce erosion and preserve the character of the hillside environment. Newly introduced landscaping shall blend with the site setting.

• (2) Drought and fire-resistant plantings are recommended.

• (3) Native vegetation and trees shall be protected from damage during

construction.

• (4) An irrigation system shall be required to establish new hillside

• landscaping.

• (5) Landscaping should preserve the penetration of sunlight to neighboring

• properties.

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(6) Small patios, terraces and pathways are allowed. They should be porous in nature wherever possible.

(7) Fences and walls enclosing a parcel are not recommended. All fences and walls are subject to review as part of the landscaping plan or design review as mandated.

(8) Railings should be transparent and compatible with the architectural

design.

(f) Views.

(1) Hillside development should minimize the obstruction of views from surrounding properties and public vantage points, with particular care taken to protect primary views.

(2) No building shall be located on a ridge.

(g) Public Safety.

(1) Class A roofing assembly is required.

(2) The fire official shall ensure the adequacy of the water supply for fire fighting purposes by requiring water mains and the upgrade of fire hydrants as necessary.

(3) Sprinkler systems shall be provided as required by the fire official.

(4) Clearance of brush or vegetative growth from structures and driveways shall be in accordance with the California Fire Code and approved by the fire official.

(5) Defensible spaces around each building and structure shall be created in accordance with the vegetation clearance requirements prescribed in California Public Resource Code 4291 and California Government Code 51182.

(6) Development shall adhere to the wildland urban interface building standards within the California Building Standards Code, as amended by Chapters 15.05 and 15.06 of the Ross Municipal Code.

(h) Geology.

(1) All newly created slopes shall be planted or otherwise protected from the effects of storm runoff and erosion within thirty days after completion of grading.

(2) Development shall avoid unstable areas on the site, such as slides, severe creep areas and debris flows. Locating improvements in such areas shall be grounds for project denial. Projects plans should include repair of all unstable areas on the site, such as slides, severe creep areas and debris flows, both in the immediate area of the proposed development and elsewhere on the site including any roadways traversing undeveloped areas as required by the town or project engineers.

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(3) Prior to any approval of a final subdivision map, all slides to be repaired shall be bonded to guarantee the repair during the normal construction of subdivision improvements. In the case of parcel maps, bonding shall be provided prior to the recordation of the parcel map.

(4) All slide repair work shall be accomplished under a building permit and the direction of a registered civil engineer specializing in soils engineering or a certified engineering geologist. At the conclusion of work, the engineer or geologist shall submit written confirmation to the town that all work accomplished under their jurisdiction is acceptable.

(5) Erosion control measures shall be required for all development. Erosion control plans shall comply with the County of Marin stormwater regulations and shall meet the National Pollutant Discharge Elimination System (NPDES) permit requirements for Marin County and Chapter 12.28 of this code.

(i) Hydrology.

(1) Residences and accessory structures shall not traverse, encroach or impede a natural watercourse or drainage swale.

(2) Site drainage shall be designed by a licensed engineer. The plan shall be designed to produce no net increase in peak runoff from the site compared to pre-project conditions. Site plans should include techniques for low impact development for stormwater management (see design review guideline 18.41.100(t)).

(j) Circulation.

(1) The design of the circulation system should provide for an adequate transition and maximum compatibility with adjoining patterns of development and open space.

(2) The design of the circulation system should follow the natural contours of

the land.

(3) The points of ingress and egress to a street shall have a minimum visual clearance commensurate with adequate safety requirements. In any event, the visual clearance shall not be less than one hundred feet. (4) All roadway improvements shall meet the specifications determined by the director of public works and town engineer. (Ord. 728 (part), 2025; Ord. 691 (part), 2018; Ord. 657 (part), 2014; Ord. 622 (part), 2011; Ord. 620 (part), 2010; Ord. 611 (part), 2008; Ord. 604 (part), 2008: Ord. 521 (part), 1993).

18.39.100 Noncompliance. Failure to comply in any respect with the conditions or approved plans constitutes grounds for the town to immediately stop work related to the noncompliance until the matter is resolved. Such violation will be subject to the enforcement penalties and procedures of Chapter 18.64 of this code. (Ord. 620 (part), 2010; Ord. 521 (part), 1993).

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18.39.120 Variances. Consistent with State law, an applicant may apply to the town council for a variance from any development regulation in this chapter, pursuant to Chapter 18.48 of this Title. (Ord. 620 (part), 2010).

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Chapter 18.40

GENERAL REGULATIONS

Sections: