The city is located in the Livermore-Amador Valley. Within the city's incorporated boundaries and within its sphere of influence are a series of major and minor hills. These hills constitute a significant topographical feature of the community because they are visible to all persons traveling on I-580 and I-680, as well as to citizens residing in and around the community. Although most of the development within the city, caused by the migration of substantial numbers of people, has occurred in the flatlands, some development has occurred in the hills and more development in the hills will occur in the future. In order to insure that a harmonious visual and functional relationship will exist between the existing natural hillside environment and the growing manmade environment, development standards specifically designed for hillside development are required. It is therefore the declared intent of the city that appropriate undeveloped land in hillside areas be placed in a hillside planned development district to be identified by the initials H-P-D, in order to accomplish the following:
A. 
To preserve significant features of a hill area in essentially their natural state as part of a comprehensive open space system;
B. 
To encourage in hill areas an alternative approach to conventional flatland practices of development;
C. 
To minimize grading and cut and fill operations consistent with the retention of the natural character of the hill areas;
D. 
To minimize the water runoff and soil erosion problems incurred in adjustment of the terrain to meet on-site and off-site development needs;
E. 
To achieve land use densities that are in keeping with the general plan; however, in order to retain the significant natural features of the hill areas, densities will diminish as the slope of the terrain increases;
F. 
To insure that the open space as shown on any development plan is consistent with the open space element shown on the general plan; and
G. 
To preserve the predominant views both from and of the hill areas and to retain the sense of identity and imageability that these hill areas now impart to the city and its environs.
(Prior code § 2-2.3201)
The following uses may be permitted in the H-P-D district:
A. 
Single-family dwellings and planned unit developments;
B. 
Recreation facilities, either for general public use or for the exclusive use of the residents of the subdivision or series of subdivisions of which the recreation facilities are a part;
C. 
Recreational vehicle storage, stables, day nurseries, child care centers and managerial offices where any such use is owned by and used exclusively for the residents of the subdivision or series of subdivisions which contain such use;
D. 
Schools, public or private, attendance at which satisfied the compulsory laws of the state;
E. 
Churches and similar religious institutions;
F. 
Public facilities, such as administrative offices and similar uses, but not including storage yards, corporation yards, or similar uses;
G. 
Employee housing (agricultural) that complies with California Health and Safety Code Sections 17008, 17021.5 and the other applicable provisions of the Employee Housing Act at California Health and Safety Code Section 17000 et seq., and to include a residential safety management plan;
H. 
Supportive housing that provides shelter for six or fewer persons in a dwelling unit, subject to the provisions of Chapter 18.107;
I. 
Transitional housing that provides shelter for six or fewer persons in a dwelling unit, subject to the provisions of Chapter 18.107;
J. 
Other uses accessory to any permitted use.
(Prior code § 2-2.3202; Ord. 2061 § 2, 2013; Ord. 2062 § 2, 2013)
Agricultural uses may be permitted in the H-P-D district subject to the granting of a use permit pursuant to the procedure and criteria specified in Chapter 18.124 of this title.
(Prior code § 2-2.3203)
A. 
Property zoned pursuant to the provisions of this chapter shall neither be developed nor shall any grading permit be issued pursuant to any provisions of this code until a hillside planned development (H-P-D) permit has been obtained pursuant to the provisions of Article II of this chapter.
B. 
As used in this section, "developed" means the submittal of any plans required by this code prior to the commencement of construction of any improvements, excepting therefrom those permitted by Section 18.76.070.
(Prior code § 2-2.3204)
The following property development standards shall apply to the H-P-D district:
A. 
Dimensions. There shall be no minimum yards, lot area, lot width, lot frontage or distance between buildings or maximum lot coverage except as may be required by an approved H-P-D permit.
B. 
Building Height. No building shall exceed two stories in height, exclusive of covered parking in the same structure.
C. 
Parking.
1. 
Quantity. For residential use there shall be not less than two covered parking spaces designated for the exclusive use of the occupant of every dwelling unit. In addition to covered parking spaces there shall be a quantity of open parking spaces not in driveways, equal to or greater than the number of dwelling units.
2. 
Location. The open parking spaces required by subsection (C)(1) shall be located within two hundred feet of every dwelling unit provided the terrain is appropriate for such placement. Wherever possible, open space parking shall be placed in groups, if six or more spaces are required; groupings may include parking within street rights-of-way, parking bays, and small parking lots, or any combination of the above.
3. 
Nonresidential Use. Parking for nonresidential uses shall also be required in a quantity commensurate with the specific use.
4. 
Covered Parking. No covered parking shall exceed one story in height.
D. 
Landscaping. All development in H-P-D districts shall include a combination of landscaping consisting of in-tensely planted and maintained areas and open space preserved in its natural condition. Unless otherwise stated in the approval of an H-P-D permit, natural open space may be used for livestock grazing.
E. 
Subdivisions. The final subdivision, land division or parcel map shall show not more than one dwelling unit on any one lot and commonly owned land and facilities on one or more additional lots.
F. 
Common Area. No final subdivision map or parcel map shall be recorded until documents pertaining to the maintenance of the privately owned open space and other facilities owned by or used in common by the subsequent owners of the various real properties within the subject development shall have been approved by the city attorney.
(Prior code § 2-2.3205)
Where applicable, the sign regulations for the R districts as set forth in this chapter shall apply to the H-P-D districts.
(Prior code § 2-2.3206)
A. 
If any land has been zoned H-P-D but no H-P-D permit has been approved thereon, no new use shall be established on such land. Any single-family residential or agricultural buildings lawfully existing at the time of the establishment of H-P-D zoning on that property may be enlarged, structurally altered, or accessory buildings may be constructed. Any remodeling or construction allowed by this section shall conform to the conditions to use applicable to the R-40 district.
B. 
"Agricultural building," as used in this chapter, shall mean any structure, except fences, for the purposes of housing farm animals or farm equipment and shall specifically exclude any building used for processing farm products on a commercial basis. The remodeling or construction of any building as permitted by this chapter shall conform to the various conditions to uses required in the R-40 district.
(Prior code § 2-2.3207)
The grading of land and maximum height of graded slopes shall be governed by provisions of the Uniform Building Code, the provisions of Title 19 of this code relating to subdivisions, and/or the provision of a comprehensive grading ordinance adopted by the city council.
(Prior code § 2-2.3208)
The purpose of the H-P-D permit is to assure that the intent and purpose of the hillside planned development district are effectuated.
(Prior code § 2-2.3209(a))
The terms and symbols used in this section shall have the following meanings:
"Base density"
means the number of dwelling units per gross acre as determined by Section 18.76.150(A).
"Contour interval"
means the difference in elevation between adjacent contour lines on a topographical or planimetric map.
"I"
means the contour interval measured in feet.
"L"
means the summation of the length of all contour lines measured in feet.
"Open space"
means landscaped areas together with areas retained in their original state without enhancement by landscaping, both of which are owned in common by the owners of the residential lots within a development.
"Ridge"
means a connected series of major and minor hills.
"Ridgeline"
means a ground line located at the highest elevation of the ridge running parallel to the long axis of the ridge.
"Weighted incremental slope (WIS)"
means a number assigned to a specific parcel of land for the purpose of determining its relative slope conditions and is determined according to the following formula:
WIS
=
0.0023IL
Area in Acres
The calculation of the WIS shall be performed pursuant to the criteria and procedure set forth in Section 18.76.140(E).
(Prior code § 2-2.3209(b))
Following are the procedures for processing an application for an H-P-D permit:
A. 
Review by Planning Commission. Upon receipt of the data required by Section 18.76.140, the planning commission shall hold a public hearing to consider the request for an H-P-D permit. The public hearing required by this section shall be given pursuant to the provisions of Government Code Section 65854. Following the public hearing, the planning commission may approve, conditionally approve, or disapprove the requested H-P-D permit. The decision of the planning commission shall be placed in resolution form and the reasons for the decision shall be specified therein. A copy of the resolution shall be transmitted to the city council and to the applicant as soon as possible after review by the planning commission. A synopsis of the planning commission's action and rationale shall be transmitted to the city council and the applicant where the planning commission's review will not occur until after the expiration of the appeal period specified in subsection E of this section; said synopsis shall be the unofficial report of the planning commissions pending receipt of the required resolution.
B. 
Review by City Council. Upon receipt of a resolution from the planning commission recommending approval of an H-P-D permit, the city clerk shall schedule a public hearing before the council with notice of the time, date and place of public hearing being given, pursuant to Government Code Section 65854. Following the public hearing the council may approve, conditionally approve, or disapprove the H-P-D permit. In approving a permit, the council may modify the recommendations of the planning commission. In making its decision, the council shall be subject to the same requirements as are placed on the commission by this section.
C. 
Referral. Council may also refer the matter back to the planning commission for further report and recommendation. The planning commission shall not be required to hold a public hearing on a matter referred back to it, but shall submit its report and recommendation within 40 days after the reference; otherwise the proposed modifications shall be deemed approved.
D. 
Denial by Planning Commission. If the planning commission recommends denial of an H-P-D permit application, no further action by the city council is necessary, unless the planning commission's decision is appealed to the city council by the applicant pursuant to the provisions of Section 18.144.020 of this title.
(Prior code § 2-2.3209(c))
In recommending approval of, or in approving an H-P-D permit, the following findings must be made:
A. 
The approval of the plan is in the best interests of the public health, safety and general welfare;
B. 
Off-site and on-site views of the ridges will not be substantially impaired. In determining which ridges are subject to this finding, the following criteria shall be used: the intents and purposes set forth in Section 18.76.010 of this chapter shall be followed;
C. 
Any grading to be performed within the project boundaries takes into account the environmental characteristics of that property, including, but not limited to, prominent geological features, existing streambeds and significant tree cover, and is designed in keeping with the best engineering practices to avoid erosion, slides or flooding, to have as minimal an effect on said environment as possible;
D. 
Streets, buildings and other manmade structures have been designed and located in such a manner as to complement the natural terrain and natural landscape;
E. 
Adequate fire safety measures have been incorporated into the design of the plan;
F. 
The plan conforms to the purpose and intent of the hillside planned development district; and
G. 
The plan is consistent with the city's general plan.
(Prior code § 2-2.3209(d))
In the recommendation of approval and in the approval of an H-P-D permit, conditions may be imposed which are deemed necessary to protect the public health, safety and general welfare in line with the standards set forth in this article.
(Prior code § 2-2.3209(e))
Any application for an H-P-D permit shall be accompanied by the following data prepared by a design team consisting of an architect, landscape architect and registered civil engineer:
A. 
A site plan showing general locations of all streets, on-street and off-street parking, bicycle paths, riding trails, hiking trails, buildings and other manmade structures; typical elevations or perspective drawings sufficient to show building height, building materials, colors, and general design; perspective drawings showing the relationship after development of the proposed buildings and the topographic features of the site; and a table listing land coverages by percentage and acreage for the following: open space (intensely landscaped and natural) coverage by housing unit roof, parking (covered, open, off-street), streets, sidewalks, paths, recreational facilities;
B. 
A topographical map showing existing contours and proposed lot lines, which may be integrated with the site plan described in subsection A of this section; the lot lines may be omitted if building locations on the site plan make proposed lot lines obvious;
C. 
A topographical map at a scale not smaller than one inch equals 100 feet showing contour lines existing prior to grading at an interval of not more than 10 feet; a grading plan showing increments of the depths of all cuts and fills in various colors or any similar display which shows the cuts, fills, depths thereof in colors; and a slope classification map showing, in contrasting colors, all land which has less than a 10 percent slope, that land which has a slope between 10 percent and twenty percent, that land which has a slope between twenty percent and 25 percent, and all land which has a slope greater than 25 percent. The director of housing and community development, or his or her designated representative, may allow a reduction in the scale of the map or an increase in the contour interval when the size of a parcel or its terrain require such changes to make the map more meaningful;
D. 
Profiles showing the relationship of the proposed project to any dominant geological or topographical features which may be on or in the vicinity of the proposed project;
E. 
The calculation of the WIS factor shall be prepared by a registered civil engineer or a licensed land surveyor, and the following criteria and procedure shall be used:
1. 
The contour map shall have 10-foot contour intervals;
2. 
The interval used in WIS calculation shall be two feet and interpolation of the contour intervals shall be made if required;
3. 
Topographic map scale:
Parcel Size
Scale
Less than 2.0 acres
1″—20′
2.0 acres to 20 acres
1″—50′
Over 20 acres
1″—100′
F. 
Any tree(s) including size and species as defined in Chapter 17.16 of this code, whether or not such tree(s) is to be removed, or destroyed, on the site plan or on a separate plat;
G. 
Sufficient dimensions to show right-of-way widths, pavement widths, radii of curvature of center lines, street grades, whether streets are to be public or private, and all proposed frontage improvements on new and existing streets;
H. 
A current preliminary soils and geological report prepared by a registered civil engineer and a registered geologist;
I. 
A detailed landscaping plan showing the natural open space which will remain upon completion of development, all existing trees (and indicating which trees are scheduled for removal), and the precise boundaries of additional landscaping; the landscape plan shall include container size of all trees and shrubs, species of all plant material, irrigation system plan, street lighting, low level path lighting, street furniture and fencing materials, dimensions and locations;
J. 
A statement in writing stipulating to the total number of bedrooms to be constructed; and
K. 
The initial plan shall indicate the density allowed by subsection A of Section 18.76.150 and the location of the proposed units. Any request for density adjustments allowed by subsection B of Section 18.76.150 shall be shown on an alternate plan detailing the location of the additional units and amenities.
Notwithstanding the requirements of this subsection, an applicant for an H-P-D permit for the development of five or more acres, which development will occur in stages, may submit general information relating to subsections A and I of this section for review by the planning commission. Precise and detailed plans setting forth the information required by these items shall be submitted to the planning commission for its review and approval prior to the approval of a tentative subdivision map, building permit or other construction authorized by the H-P-D permit.
(Prior code § 2-2.3209(f)
A. 
Base Density. A base density for a piece of property shall be determined by the following:
Percent slope
10%
15%
20%
25%
Greater than 25%
*WIS
9.9
14.9
19.6
24.2
Greater than 24.2
Base Density
3.5
2.8
1.8
1
0.2
Notes:
*Corrected number values.
Any WIS not shown in the table shall be determined by interpolation, using the graph set forth in Exhibit A of the ordinance codified in this chapter, and incorporated in this chapter by reference.
B. 
Density Adjustments. The effectiveness of hillside development can be affected by a number of factors such as the physical characteristics of a specific parcel, the amount of landscaped and natural open space existing within a development, the existence of amenities within a development and the number of people who will reside in the hill area. Therefore, in order to encourage hillside developments which take into consideration the factors provided in this subsection, adjustments may be made in the base density in the recommendation for approval and approval of an H-P-D permit, pursuant to any of the following:
1. 
The existence of open space beyond that required by Section 18.76.160;
2. 
The existence of amenities or on-site or off-site improvements which are not normally found or required in residential developments;
3. 
The existence of a mixture of housing types which provides a variation in the appearance of the development and allows a range of housing prices;
4. 
The existence of landscaping of a type, size and quantity which exceeds that of a standard residential development;
5. 
The existence of a topographical feature, including, but not limited to, a cliff or deep ravine, or extensive land area over 25 percent slope, of a magnitude which causes the WIS to be significantly greater than would be the case if the topographic feature was not considered; and
6. 
The offer to and acceptance by the city of land in excess of the parkland dedication requirements of Chapter 17.46 of this code.
(Prior code § 2-2.3209(g))
The percentage of the parcel to be developed which must remain in open space and/or public parkland shall be a minimum of 25 percent plus one and one-half times the WIS factor. Public parkland shall include only those areas which are offered for dedication as public parks and which are accepted by the city.
(Prior code § 2-2.3209(h))
A. 
Size and Treatment. In order to keep all graded areas and cuts and fills to a minimum, to eliminate unsightly grading and to preserve the natural appearance and beauty of the property as far as possible as well as to serve the other specified purposes of this chapter, specific requirements may be placed on the size of areas to be graded or to be used for building, and on the size, height and angles of cut slopes and fill slopes and the shape thereof. In appropriate cases retaining walls may be required.
B. 
Restrictions. All areas indicated as natural open space on the approved development plan shall be undisturbed by grading, excavating, structures or otherwise except that riding trails, hiking trails, picnic areas, stables and similar amenities may be placed in natural open space pursuant to the approval of an H-P-D permit.
C. 
Landscaping. The H-P-D permit shall include the planting of newly created banks or slopes for erosion control or to minimize their visual effect.
(Prior code § 2-2.3209(i))