La Mirada Municipal Code Ch. 20.16 Design Standards

To ensure that a proposed subdivision shall reflect the best interests of the city, all subdivisions under the provisions of this title shall conform to the standards of subdivision design of this title and the Standard Details. In the event of conflict between this title and the Standard Details, this title shall govern.

(Ord. 121 Art. 4 (part), 1967).

The street pattern of each proposed subdivision shall reflect the general plan of the city and shall be designed in accordance with the following design standards:

(1) Street design shall be in accordance with the provisions of Sections 20.16.090 and 20.16.100, "Minimum Requirements;"

(2) Reserve strips controlling the access to streets or other public right-of-way shall not be approved unless such strips are deemed necessary by the city planning commission for the protection of the public welfare of substantial property rights, and in no case unless the control and disposal of the land comprising such strips are placed in the control of the city;

(3) Where the subdivision adjoins unsubdivided land, streets in the subdivision shall ordinarily be extended to the adjacent unsubdivided land as prescribed by the city planning commission to provide access to said unsubdivided land in the event of its future subdivision;

(4) No street name shall be used which duplicates or may be confused with the name of any street existing in the city or any other Los Angeles County city or county street name and all street names shall be approved by the planning commission;

(5) Streets and alleys at their present intersections shall be provided with twenty foot radius turns at property lines in all subdivisions;

(6) The length of cul-de-sac streets in a residential subdivision shall not exceed five hundred feet except that a cul-de-sac of up to six hundred feet in length may be permitted provided that it has frontage of no more than sixteen lots excluding corner lots except in undue hardships where minor variances may be granted;

(7) All streets shall normally intersect as nearly as possible at right angles, and the centerlines of intersecting streets shall be tangents or have a radius greater than six hundred feet for a distance of one hundred feet from their intersection. Streets entering upon opposite sides of any given street shall have their centerlines directly opposite each other or the centerlines shall be offset by at least one hundred fifty feet for all minor residential streets and two hundred feet for all other streets, except in undue hardship where minor variances may be granted;

(8) Entrance from a frontage road to a major thoroughfare shall be designed to assure satisfactory traffic flow and safety;

(9) Curbs shall be concrete vertical type, Standard Detail No. A-1;

(10) Sidewalks shall be unobstructed by utility installations wherever reasonably possible, or by planting, and shall be made of concrete and shall be at least four feet wide, Standard Detail No. A-2;

(11) Grade of streets normally shall not be less than one- half percent and shall not be greater than ten percent for minor streets and seven percent for collector streets;

(12) Excessive fill and cut slopes when necessary in the opinion of the city engineer shall have an easement equal to the cut or fill distance plus ten feet;

(13) Whenever a street shall intersect another street, the maximum grade of either street within an intersection shall be four percent except in undue hardships where minor variances may be granted;

(14) The minimum distance between points of access to a major thoroughfare shall be fifteen hundred feet;

(15) The structural design of the roadbed shall include determination of the thickness of subbases, bases and surfacings to be placed over subsoils, based on standards of the superintendent of streets. In no case shall the thickness of base material be less than six inches nor shall the thickness of asphaltic concrete surfacing be less than two inches.

(Ord. 121 § 400, 1967).

(a) The width of blocks shall ordinarily be sufficient to allow for two tiers of lots with rear easements as required.

(b) Depth and width of properties reserved for commercial or industrial purposes shall be adequate to provide for development which includes off-street parking and loading areas.

(c) Block lengths in residential subdivision shall not exceed fifteen hundred feet.

(d) Pedestrian paths at least twelve feet in width shall be provided across blocks when required for public convenience or access to school playgrounds, shopping centers or to other community facilities. All paths shall be improved according to Section 20.16.090 and shall be delineated in a manner approved by the city planning commission, provided, that where the average grade of the path right-of-way within a block prior to improvement exceeds fifteen percent, groups of steps of concrete or other approved material shall be placed at appropriate locations in the path. In all paths within which steps are provided, the portion of the path above such steps shall slope away from the steps for a minimum distance of ten feet.

(e) Residential lots shall have an area of at least six thousand square feet and a minimum average width of sixty feet and lots that fan out from a cul-de-sac must have a minimum frontage of forty feet. Lot arrangement and design shall be such that lots will provide satisfactory sites for buildings and shall be properly related to topography and to existing and probably future requirements. To this end all lots shall normally be of a proportion to provide a minimum average width in accordance with the following schedule:

(f) In residential subdivisions corner lots and reversed corner lots shall have an area of at least ten percent greater than that of the minimum lot area required.

(g) Through lots, reverse frontage lots and reverse corner lots shall be avoided except where essential to provide separation of residential development from traffic arteries or otherwise required by topography and/or orientation.

(h) Side lot lines shall be substantially perpendicular or radial to street lines.

(i) No subdivision shall be accepted which leaves unsubdivided islands, strips, or parcels of property unsuited for subdividing and not accepted by the city for appropriate use, and all lots must be buildable except those dedicated to public use.

(j) Residential lots abutting a major thoroughfare shall not front on such major thoroughfare, but shall front on a minor or collector street.

(k) Commercial lots shall have an area of at least ten thousand square feet and a minimum frontage of seventy feet.

(l) Industrial lots shall have an area of at least twenty thousand square feet and a minimum frontage of one hundred feet.

(Ord. 121 § 401, 1967).

(a) Planting shall be provided in, or bordering all public ways, with trees of an approved type which shall be provided in amounts of two trees for each sixty feet of lot line bordered by the public way or as directed by the superintendent of streets.

(b) Existing trees shall be preserved within any public way whenever such trees are suitably located, healthy or of a desirable variety and when approved grading shall so permit. When such trees exist the city staff shall make an inspection to determine the health and desirability of species and make its recommendations to the city planning commission.

(Ord. 121 § 402, 1967).

(a) Monuments shall be set at or near all angle points of tangency in the boundary of the subdivision, at intervals not to exceed five hundred feet along the subdivision boundary or at such lesser distances as required by the city engineer, at the intersections of all street lines with the subdivision boundaries at all street intersections at the beginning and ending of curves of the center lines and at other locations that may be specified by the city engineer. In no case shall there be less than two monuments on any exterior subdivision. boundary line or less than two street monuments in any street. Street monuments shall be set on centerlines or offset as directed by the city engineer. All monuments set shall be of a type and standard as established by the Los Angeles County engineer.

(b) Corners and curve points of all lots in a subdivision shall be marked by hubs all of which shall be identified by the number of the registered engineer or land surveyor surveying the subdivision which shall be legibly stamped on the tack or attached noncorrosive tag. When the lot corner hubs are within the area affected by street improvement work, they may be temporarily marked by offset hubs.

(Ord. 121 § 403, 1967).

(a) The following definition of terms apply to the minimum drainage requirements contained in this title:

(1) "Primary drainage channels or conduits" mean those channels or conduits which have a drainage area of more than 1.0 square miles;

(2) "Minor drainage channels or conduits" mean those channels or conduits having a drainage area of 1.0 square miles or less;

(3) "Inundation" is used to indicate ponded water or water in motion of sufficient depth to damage property due to the mere presence of the water or deposition of silt;

(4) "Flood hazard" means overflow of water having sufficient velocity to transport or deposit debris, to scour the surface soil, or to dislodge or damage buildings, or to cause erosion of the banks of channels;

(5) "Possible flood hazard" means possible extension of areas denoted as subject to "flood hazard" and shall reflect the uncertainty of degree or extent of bank erosion;

(6) "Sheet overflow" means water of minor depth either quiescent or flowing at velocities less than those necessary to produce serious scour;

(7) "Ponding of local storm water" means the standing of water in local depressions. As distinguished from "sheet overflow" this water originates on or in the vicinity of the property and due to the condition of the ground surface is unable to reach a drainage channel or conduit.

(b) Runoff design shall be made for the frequency of occurrence hereinafter stipulated in these standards of modified rational method using basic data in accordance with the requirements set forth in the Standard Specifications. Runoff design shall accommodate the full and future developments within the drainage area. In cases where such drainage areas are underdeveloped fully improved conditions shall be determined for future by conditions as indicated in the general plan of the city for future development and by the zoning ordinance of the jurisdiction within which such areas are located. Any outlet channel required to carry storm water from the proposed subdivision to a defined drainage channel or conduit shall be in accordance with these standards for the ultimate state of development in the drainage area resulting from the particular subdivision.

(c) Drainage channels and conduits directly affecting the proposed subdivision shall have the following minimum capacities:

(1) Primary drainage channels and conduits shall have sufficient capacity to contain a twenty-five-year frequency of occurrence runoff;

(2) Minor drainage channels or conduits shall have sufficient capacity to contain a ten-year frequency of occurrence runoff, including undefined overflow originating within the tract or adjacent thereto.

(d) Storm waters within street areas shall be placed in closed conduits when the maximum depth of in-gutter runoff computed in accordance with the provisions of the supplemental design standards in the specifications exceeds desirable depths in relationship to the velocity, as determined by the city engineer.

(e) Proposed subdivision shall not cause inundation or flood hazard conditions of existing inhabited areas.

(f) Drainage shall be accomplished by gravity without surcharge into catch basins or manholes except by design.

(g) Catch basins shall have inlets of varying lengths so designed that the water is diverted into the catch basin without a reversed direction of the flow of the water. The inlets shall be designed in accordance with Standard Detail No. A-3.

(h) Drainage channels, conduits and appurtenances shall conform in all respects to good engineering practice.

(Ord. 121 § 404, 1967).

Street name signs shall be installed by the subdivider at all intersections of name streets and paths and shall be conspicuous to pedestrian and vehicular traffic in all directions. The installation at the intersections of two such ways shall consist of at least one four-way street name sign and post; provided that where the pavement width of one or both of the streets exceeds forty feet, two signs shall be installed at such intersection; provided that at least one such sign shall be installed wherever there shall occur an angular change of direction of a street centerline of sixty degrees or more. In all cases, installation shall be made as close as practicable to the curb. All street name signs shall be of a type specified and shall be installed in accordance with the specifications as prepared by the superintendent of streets. If more than two streets intersect, sufficient signs shall be installed clearly to identify all such streets.

(Ord. 121 § 405, 1967).

(a) Adequate lighting shall be provided in all subdivisions along streets, paths or other pedestrian or vehicular ways. An agreement to so provide by the subdivider shall be accomplished prior to acceptance of a final plan.

(b) Street lighting shall be accomplished by installation of standards carrying luminaries mounted over the roadway of size, height and type in accordance with the specifications, as established by the superintendent of streets.

(c) Spacing of street lighting standards, and type and size of luminaries on all streets which primarily serve residential dwellings shall be such as to furnish not less than 0.075 foot candle or more than 0.6 foot candle over any portion of the street right-of-way. The average illumination as determined by the superintendent of streets shall be approximately 0.2 foot candle.

(d) Wherever existing trees or other plants are to be preserved within the street right-of-way, street lighting standards shall be carefully located in such a manner as to receive minimum interference from such trees or plants.

(Ord. 121 § 406, 1967).

(a) Curbs, gutters and sidewalks shall be required in all residential subdivisions in accordance with Standard Detail No. A-1 and A-2.

(b) Minor and collector streets shall be required in all residential subdivisions in accordance with Standard Detail No. A-4.

(Ord. 121 § 407, 1967).

(a) Curbs and gutters shall be required in all commercial and industrial subdivisions in accordance with Standard Detail No. A-1 and A-2.

(b) Commercial type sidewalk with tree wells shall be required in all commercial subdivisions in accordance with Standard Detail No. A-2.

(c) Streets shall be required in all commercial subdivisions in accordance with Standard Detail No. A-3.

(Ord. 121 § 408, 1967).